Vegetables of Canada

Vegetables of Canada NRC Monograph Publishing Program Editor: R.H. Haynes, OC, FRSC (York University) Editorial Bo...

Author: Ernest Small | Derek B. Munro

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Vegetables of Canada

NRC Monograph Publishing Program Editor: R.H. Haynes,

OC, FRSC

(York University)

Editorial Board: W.G.E. Caldwell, FRSC (University of Western Ontario); P.B. Cavers (University of Western Ontario); G. Herzberg, CC, FRS, FRSC (NRC, Steacie Institute of Molecular Sciences); K.U. Ingold, OC, FRS, FRSC (NRC, Steacie Institute for Molecular Sciences); W. Kaufmann (Editor-in-Chief Emeritus, Annual Reviews Inc., Palo Alto, CA); M. Lecours (Université Laval); L.P. Milligan, FRSC (University of Guelph); G.G.E. Scudder, FRSC (University of British Columbia); E.W. Taylor, FRS (University of Chicago); B.P. Dancik, Editor-in-Chief, NRC Research Press (University of Alberta) Inquiries: Monograph Publishing Program, NRC Research Press, National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada

Correct citation for this publication: Munro, D.B., and Small, E. 1997. Vegetables of Canada. NRC Research Press, Ottawa, Ontario, Canada. 417 p.

A Publication of the National Research Council of Canada Monograph Publishing Program

Vegetables of Canada Derek B. Munro, System Data Manager and Ernest Small, Principal Research Scientist Research Branch Agriculture and Agri-Food Canada Central Experimental Farm Ottawa, Ontario, Canada K1A 0C6 (http://res.agr.ca/ecorc/)

NRC RESEARCH PRESS Ottawa 1997

© 1997 National Research Council of Canada All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted by any means, electronic, mechanical, photocopying, recording or otherwise, without the written permission of the National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada. Printed in Canada on acid-free paper ISBN 0-660-16708-5 NRC No. 40700

Canadian Cataloguing in Publication Data Munro, Derek B., 1950– Vegetables of Canada Issued also in French under title: Les légumes du Canada. Issued by the National Research Council of Canada. Includes an abstract in French. Includes bibliographical references and index. ISBN 0-660-16708-5 1. Vegetables — Canada. 2. Food crops — Canada. I. Small, Ernest, 1940– . II. National Research Council Canada. III. Title. SB320.8.C3M86 1997

615′.0971

C96-980455-5

Contents Common name guide to the vegetables of Canada discussed in detail vii Scientific name guide to the vegetables of Canada discussed in detail ix Abstract xi Résumé xii Preface xiii Medicinal warning xv Acknowledgments xvi Sources of illustrations xvi Introduction 1 What is a vegetable? 1 The evolution of vegetables 2 Scope of this book 3 Crops included 3 Crops excluded 3 Potential vegetables 5 Use of plant parts as vegetables 6 Preserving germplasm of heritage vegetable varieties 7 Diseases and pests 8 Recommended reading on vegetables 9 World Wide Web internet links 9 The vegetable economy of Canada 11 Important vegetables of Canada (including farm value statistics) 11 Regional production 17 Vegetables and crop diversification in Canada 19 Plant classification and plant names 20 Natural and artificial classifications 20 The importance of nomenclature 21 What is a variety? 22 French names 22 Format used for presentation of scientific and common names 23 Detailed information on vegetables of Canada (alphabetized by genus, from Abelmoschus to Zea) 24 Bibliography 387 Index of English names 407 Index of French names 411 Index of scientific (Latin) names 413 Index of Asian language names 417

Common name guide to the vegetables of Canada discussed in detail (Many of the vegetables discussed in this book are known by more than one name. Only the most frequently encountered names are given here. For a complete list of all common names mentioned and their occurrence throughout the book, see the index of English names at the end of the book, and also the index of Asian names.) Alfalfa (Medicago sativa) 271 Amaranth (Amaranthus tricolor) 43 Artichoke globe (Cynara scolymus) 188 Jerusalem (Helianthus tuberosus) 213 Arugula (see rocket) Asparagus (Asparagus officinalis) 61 Aubergine (see eggplant) Bean asparagus (see bean, yard-long) broad (see bean, faba) common (Phaseolus vulgaris) 297 faba (Vicia faba) 364 lima (Phaseolus lunatus) 302 mung (Vigna radiata) 372 scarlet runner (Phaseolus coccineus) 306 soya (see soybean) Windsor (see bean, faba) yard-long (Vigna unguiculata subsp. sesquipedalis) 376 Beet (Beta vulgaris subsp. vulgaris) 82 Bok choy1 Broccoli (Brassica oleracea var. italica) 114 Broccoli raab (Brassica ruvo) 115 Brussels sprouts (Brassica oleracea var. gemmifera) 109 Burdock, great (Arctium lappa) 58 Cabbage (Brassica oleracea var. capitata) 105 celery (see cabbage, Chinese) Chinese (Brassica rapa subsp. pekinensis) 126 savoy (Brassica oleracea var. sabauda) 106 Cardoon (Cynara cardunculus) 185 Carrot (Daucus carota) 192 Cauliflower (Brassica oleracea var. botrytis) 101 Celeriac (Apium graveolens var. rapaceum) 55 Celery (Apium graveolens var. dulce) 51 turnip-rooted (see celeriac) Chard, Swiss (Beta vulgaris subsp. cicla) 79 Chicory (Cichorium intybus) 151 1

Chop suey green (Chrysanthemum coronarium) 145 Chrysanthemum, garland (see chop suey green) Collard (see kale) Corn (Zea mays) 379 Corn salad (Valerianella locusta) 361 Cress Garden (Lepidium sativum) 245 Upland (Barbarea verna) 70 Water (see watercress) Cucumber (Cucumis sativus) 167 African (see kiwano) bitter (see melon, bitter) Chinese (Cucumis melo var. conomon) 162 horned (see kiwano) Dandelion (Taraxacum officinale) 351 Eggplant (Solanum melongena) 331 Endive (Cichorium endivia) 148 Belgian (see chicory) French (see chicory) Escarole (see endive) Fennel, Florence (Foeniculum vulgare var. azoricum) 202 Fern, ostrich (Matteuccia struthiopteris) 264 Fiddlehead (see fern, ostrich) Gobo (see burdock, great) Good King Henry (Chenopodium bonus-henricus) 142 Gourd bottle (Lagenaria siceraria) 240 calabash (see gourd, bottle) sponge (see loofah, smooth) wax (Benincasa hispida) 76 Groundnut (Apios americana) 47 Gumbo (see okra) Hop (Humulus lupulus) 219 Kale (Brassica oleracea var. viridis) 119 Chinese (Brassica alboglabra) 119 Scotch (Brassica oleracea var. sabellica) 119 sea (Crambe maritima) 157 Kiwano (Cucumis metuliferus) 164

“Pei tsai” and “pai-tsai” as well as “bok choy” and “bok choi” are sometimes used interchangeably to refer to both Chinese mustard (Brassica rapa subsp. chinensis) and Chinese cabbage (Brassica rapa subsp. pekinensis).

viii

Kohlrabi (Brassica oleracea var. gongylodes) 112 Leek (Allium ampeloprasum) 29 Lettuce (Lactuca sativa) 234 lamb’s (see corn salad) miner’s (see purslane, winter) Loofah angled (Luffa acutangula) 248 smooth Luffa aegyptiaca) 251 Mâche (see corn salad) Maize (see corn) Melon, bitter (Momordica charantia) 279 Mizuna (Brassica rapa subsp. nipposinica) 126 Mustard celery (see mustard, Chinese) Chinese (Brassica rapa subsp. chinensis) 126 spinach (Brassica perviridis) 123 Mustard greens (Brassica juncea) 93 Nappa (Brassica rapa subsp. pekinensis) 126 Okra (Abelmoschus esculentus) 24 Onion (Allium cepa) 33 Japanese bunching (Allium fistulosum) 38 Orach, garden (Atriplex hortensis) 67 Oyster plant (see salsify) black (see scorzonera) Pak choy (see mustard, Chinese) Parsley turnip-rooted (Petroselinum crispum var. tuberosum) 294 Hamburg (see parsley, turnip-rooted) Parsnip (Pastinaca sativa ) 290 Pea (Pisum sativum) 309 Pei tsai1 (see mustard, Chinese; also see cabbage, Chinese) Pepper (Capsicum annuum) 137 Potato (Solanum tuberosum) 335 sweet (Ipomoea batatas) 229 Pumpkin (see squash)

1


Purslane (Portulaca oleracea) 315 winter (Montia perfoliata) 283 Radicchio (see chicory) Radish (Raphanus sativus) 318 Rampion (Campanula rapunculus) 134 Rappini (= edible-leaved turnip; see turnip) Rocket (Eruca vesicaria) 199 Rutabaga (Brassica napus subsp. rapifera) 96 Salsify (Tragopogon porrifolius) 358 black (see scorzonera) Spanish (see scorzonera) Savoy cabbage (see cabbage, savoy) Savoy, Chinese (Brassica rapa subsp. narinosa) 127 Scorzonera (Scorzonera hispanica) 324 Skirret (Sium sisarum) 327 Soybean (Glycine max) 207 Spinach (Spinacia oleracea) 346 Malabar (Basella alba) 73 New Zealand (Tetragonia tetragoniodes) 355 water (Ipomoea aquatica) 226 Squash (the following four species are known both as squash and pumpkin) Cucurbita argyrosperma 173 Cucurbita maxima 175 Cucurbita moschata 178 Cucurbita pepo 180 Swede (see rutabaga) Tomato (Lycopersicon esculentum) 254 currant (Lycopersicon pimpinellifolium) 261 Turnip (Brassica rapa subsp. rapa) 130 Vegetable marrow (see squash, Cucurbita pepo) Vegetable oyster (see salsify) Vegetable sponge (see loofah, smooth) Watercress (Nasturtium officinale) 285 Yam (see potato, sweet) Zucchini (see squash, Cucurbita pepo)


Scientific name guide to the vegetables of Canada discussed in detail (Many of the vegetables discussed in this book are known by more than one scientific name. The correct (recommended) names are given here. For a complete list of scientific names of all plants mentioned and their occurrence throughout the book, see the index of scientific (Latin) names at the end of the book.) Abelmoschus esculentus (okra, gumbo) 24 Allium ampeloprasum (leek) 29 cepa (onion) 33 fistulosum (Japanese bunching onion, Welsh onion) 38 Amaranthus tricolor (amaranth) 43 Apios americana (groundnut) 47 Apium graveolens var. dulce (celery) 51 graveolens var. rapaceum (celeriac, turnip-rooted celery) 55 Arctium lappa (great burdock, gobo) 58 Asparagus officinalis (asparagus) 61 Atriplex hortensis (garden orach) 67 Barbarea verna (upland cress) 70 Basella alba (Malabar spinach) 73 Benincasa hispida (wax gourd) 76 Beta vulgaris subsp. cicla (Swiss chard) 79 vulgaris subsp. vulgaris (beet) 82 Brassica alboglabra (Chinese kale) 119 juncea (mustard greens) 93 napus subsp. rapifera (rutabaga, swede) 96 oleracea var. botrytis (cauliflower) 101 oleracea var. capitata (cabbage) 105 oleracea var. gemmifera (brussels sprouts) 109 oleracea var. gongylodes (kohlrabi) 112 oleracea var. italica (broccoli) 114 oleracea var. sabauda (savoy cabbage) 106 oleracea var. sabellica (Scotch kale) 119 oleracea var. viridis (kale, collard) 119 perviridis (spinach mustard) 123 rapa subsp. chinensis (Chinese mustard, celery mustard, pei tsai,1 bok choy,1 pak choy) 126 rapa subsp. narinosa (Chinese savoy) 126 rapa subsp. nipposinica (mizuna) 126 1

rapa subsp. pekinensis (Chinese cabbage, bok choy,1 pei tsai,1 nappa 126 rapa subsp. rapa (turnip, rappini) 130 ruvo (broccoli raab) 115 Campanula rapunculus (rampion) 134 Capsicum annuum (pepper) 137 Chenopodium bonus-henricus (good King Henry) 142 Chrysanthemum coronarium (chop suey green, garland chrysanthemum) 145 Cichorium endivia (endive, escarole) 148 intybus (chicory, raddicchio, Belgian endive, French endive) 151 Crambe maritima (sea kale) 157 Cucumis melo var. conomon (Chinese cucumber) 162 metuliferus (African cucumber, horned cucumber, kiwano) 164 sativus (cucumber, common cucumber) 167 Cucurbita argyrosperma (pumpkin, squash) 173 maxima (squash, pumpkin) 175 moschata (crookneck squash) 178 pepo (pumpkin, squash) 180 Cynara cardunculus (cardoon) 185 scolymus (globe artichoke) 188 Daucus carota (carrot) 192 Eruca vesicaria (rocket, arugula) 199 Foeniculum vulgare var. azoricum (Florence fennel) 202 Glycine max (soybean) 207 Helianthus tuberosus (Jerusalem artichoke) 213 Humulus lupulus (hop) 219 Ipomoea aquatica (water spinach) 226 batatas (sweet potato) 229 Lactuca sativa (lettuce) 234 Lagenaria siceraria (bottle gourd, calabash gourd) 240


x

Lepidium sativum (garden cress) 245 Luffa acutangula (angled loofah) 248 aegyptiaca (smooth loofah, sponge gourd, common vegetable sponge) 251 Lycopersicon esculentum (tomato) 254 pimpinellifolium (currant tomato) 261 Matteuccia struthiopteris (ostrich fern, fiddlehead) 264 Medicago sativa (alfalfa) 271 Momordica charantia (bitter melon, bitter cucumber) 279 Montia perfoliata (winter purslane, miner’s lettuce) 283 Nasturtium officinale (watercress) 285 Pastinaca sativa (parsnip) 290 Petroselinum crispum var. tuberosum (turnip-rooted parsley, Hamburg parsley) 294 Phaseolus coccineus (scarlet runner bean) 306 lunatus (lima bean) 302 vulgaris (bean, common bean) 297


Pisum sativum (pea) 309 Portulaca oleracea (purslane) 315 Raphanus sativus (radish) 318 Scorzonera hispanica (scorzonera, black salsify, Spanish salsify, black oyster plant) 324 Sium sisarum (skirret) 327 Solanum melongena (eggplant, aubergine) 331 tuberosum (potato) 335 Spinacia oleracea (spinach) 346 Taraxacum officinale (dandelion) 351 Tetragonia tetragoniodes (New Zealand spinach) 355 Tragopogon porrifolius (salsify, oyster plant, vegetable oyster) 358 Valerianella locusta (corn salad, mâche, lamb’s lettuce) 361 Vicia faba (faba bean, broad bean, Windsor bean) 364 Vigna radiata (mung bean) 372 unguiculata subsp. sesquipedalis (yard-long bean, asparagus bean) 376 Zea mays (corn, maize) 379

Abstract This book is a comprehensive, extensively illustrated, practical reference guide to Canadian vegetables. It covers both commercial and home garden crops, and includes essentially all of the major, minor, and potentially new vegetables of Canada. Information is presented in categories, allowing the reader to quickly find details needed for particular purposes. Categories of information covered in considerable detail for about 100 vegetables include: nomenclature (botanical family, English and French names, correct scientific name and common scientific synonyms), description and classification (including cultivars), uses (including a guide to recipe sources), importance (nationally and internationally, including statistics where available), detailed cultivation requirements (soil, climate, propagation, harvest, storage), human interest information, selected key literature, and a summary evaluation of problems and potential from an economic and agricultural viewpoint. All species discussed in detail are illustrated, with over 200 drawings in the book. Brief information is presented on many additional species of lesser importance to Canada. Introductory material reviews such topics as: just what a vegetable is, the vegetable economy of Canada, preserving germplasm, crop diversification, and internet sources of information. While the publication is oriented to Canada, it is also a useful reference text for most of the vegetables that are grown in other temperate countries.

Résumé Cet ouvrage exhaustif et richement illustré constitue un guide pratique des légumes cultivés au Canada. On y traite de l’ensemble des légumes cultivés en potager ainsi qu’à l’échelle commerciale, soit les principaux légumes, ceux plus rares ainsi que ceux qui pourraient faire leur apparition dans l’agriculture canadienne. L’information est divisée en catégories, ceci afin de faciliter la recherche de données précises pour les lecteurs. On retrouvera de l’information détaillée sur une centaine de légumes, y compris leur nomenclature (famille botanique, noms français et anglais, nom scientifique exact et synonymes scientifiques courants), leur description et classification (y compris les cultivars), la façon de les consommer (y compris des renvois à des recettes), leur importance (à l’échelle nationale et internationale, y compris les statistiques commerciales, le cas échéant), des détails quant à leur culture (sol, climat, propagation, récolte, entreposage), de l’information d’intérêt humain, des renvois à de l’information d’importance, et une évaluation sommaire des problèmes et du potentiel des points de vue économique et agricole. L’ouvrage comprend plus de 200 illustrations des principales espèces. On y fait aussi le survol des espèces moins importantes pour l’économie canadienne. Dans l’introduction, on retrouve de l’information sur des sujets tels que ce qu’est un légume, l’économie de la culture des légumes au Canada, la préservation du matériel génétique, la diversification des cultures et les sources d’information sur l’Internet. Bien qu’elle rende compte de la culture des légumes au Canada, cette publication s’avérera un outil de référence utile sur la culture de légumes dans les autres pays tempérés.

Preface This book is a guide to the classification, biodiversity, agriculture, economics, and prospects of virtually all vegetables grown in Canada. So much information is available for many cultivated plants that the renowned American student of horticulture, L.H. Bailey, once pointed out that the art of preparing a reference work to such plants is not in deciding what to include, but rather in choosing what to exclude. Our aim has been to provide a manual of general agricultural and economic information about the vegetables of Canada, including the familiar, unusual, and potential. Most Canadian provinces regularly issue production recommendations for the principal vegetable crops. This book is neither intended to provide such local recommendations, nor to be a guide to gardening of vegetables in Canada; however, much of the information will be useful for both the commercial and home gardener. Anyone interested in Canadian vegetables should find much basic information here. Our intended audience is broad and includes executives in government and the private sector who require a rapid overview of information on given crops (e.g., for establishing, reviewing, and altering priorities for research) information service specialists in government (e.g., for answering inquiries on unfamiliar crops) farmers and research station personnel (e.g., for considering suitable crops for diversification in their region and soil type) teachers in educational institutions (e.g., for use as a reference text to all the vegetables of interest in Canada) staff in agri-food industries (e.g., for identifying regions of Canada where particular vegetables are grown). Indeed, although this book is titled Vegetables of Canada, much of the information provided will also be of interest in the northern United States. This is because some or all of 26 American states (including the American agricultural breadbasket, California) lie north of the southernmost Canadian boundary, and the same vegetables are or can be grown. Crop diversification is a principal current concern for Canadian agriculture. New crops require research, development, production, and marketing. To make sound choices and decisions, knowledge and background information of the status of crops actually and potentially available are essential. Unfortunately, much of this information exists in widely scattered, often obscure locations. Surprisingly, in view of the importance of crop plants to agriculture, no satisfactory information base presently brings together fundamental data that would allow intelligent, efficient selection of potentially valuable new crops in Canada, for purposes of diversification, sustainability, and responsiveness to new markets. The present treatment provides an overview of information on vegetables of Canada, which we hope will contribute to future development of the vegetable industry.

xiv


Naturally, a work of this type can only present a summary of information, so we have provided extensive references and have suggested where to obtain additional information. Because many vegetables are familiar, some readers may need less general information and more specific details. We have endeavored to identify sources where these readers may find such information in up-to-date agricultural treatments. With less-familiar vegetables, our treatments are usually considerably longer than indicated by the importance of the vegetable in Canada. This detail reflects the need for more information for the less commonly grown vegetables, where literature is limited or unavailable in the context of Canadian cultivation. The potential of little-known vegetables is often greater than one might think. Who would imagine, for example, that more than 100 tonnes of dandelion greens, worth $400 000, are marketed in Toronto alone in some years? In preparing this work, we have been impressed by how much important literature about the vegetables grown in Canada lies buried in obscure Canadian sources or is available from foreign countries. We trust that this book will enable more people to access more information relevant to Canadian vegetables than they could before. The importance of most of the categories of information included will be self-evident; however, three require comment. Notable vegetable varieties are mentioned (in “Example cultivars” under “Cultivation notes”) simply to indicate some popular forms; their inclusion should not necessarily be interpreted as a recommendation. Under “Example recipes” we have included sources of recipes for marketing purposes, because consumer acceptance of vegetables, especially unfamiliar ones, depends heavily on such information. Then, since “man does not live by bread alone,” we have included human interest information in “Curiosities” under “Additional notes.” Learning about some of the fascinating history and science of vegetables can increase our respect for them and perhaps stimulate us to pay more attention to what they can do for us.

Medicinal warning For thousands of years plants have been used in treating human diseases. Indeed, many plant-derived medicines continue to be used today; others are being investigated for their pharmacological potential. Although we have provided information on many historical medicinal uses of vegetables, most of these are now considered unsuitable, and some are even considered dangerous. Where we have mentioned potential pharmacological values of plants, these require further research. As we note for a number of less-familiar, less-domesticated vegetables, their consumption should be limited as harmful constituents may be present. Moreover, just as prescription medicines can have different effects on individuals, so can some plants. Indeed, as we point out, even for some familiar vegetables (e.g., faba bean), some individuals can have toxic reactions after ingestion. Accordingly, the reader should rely on qualified medical advice before using vegetables for medical or pharmacological applications. However, we do not want to leave this caution on a sour note. Vegetables are healthful, nutritious, delicious, and an indispensable part of the Canadian diet.

Acknowledgments We would like to thank the following for their important help: P. Catling and K. Switzer-Howse for their strong administrative backing of this project; B. Brookes, B. Flahey, M. Jomphe, and L. Yuzyk for preparing several figures; M. Jomphe for preparing a layout template for this book; B. Brookes for acquiring and verifying information; J. Cayouette for checking French names; G. Baillargeon and S. Warwick for review of our treatment of Brassica; B. Fraleigh, A. Francis, and C. Crompton for review of the entire preliminary manuscript; S. Redhead for providing information on mushrooms; G. Staples and D.F. Austin for information on Ipomoea; H. Apple and S. Rempel for information on the Heritage Seed Program; E. Gavora and the other librarians of our centre for obtaining considerable literature; K. Spicer for organizing much of the literature; and J. Buckley and E. Kidd for expert editing and many suggestions that improved the text. We have incorporated numerous copyright-free illustrations into the manuscript, produced by anonymous artists over a century ago (as Alice said, “What is the use of a book … sans pictures?”); their contribution, albeit involuntary, is also appreciated.

Sources of illustrations Agriculture and Agri-Food Canada Media Services slide collection. Page 266. Bailey, L.H. 1900–1902. Cyclopedia of American Horticulture. 4 Volumes. Virtue & Company, Toronto, ON, Canada. 2016 p. Page 248. Brookes, B.—illustrator (Agriculture and Agri-food Canada, Ottawa). Pages 61 and 364. Flahey, B.—illustrator (Agriculture and Agri-food Canada, Ottawa). Page 344. Harter, J. (Editor). 1988. The plant kingdom compendium. Bonanza Books, New York, NY, USA. 374 p. Pages 11 (tomato), 16 (corn), 16 (green peas), 16 (beet), 16 (carrot), 17 (cabbage), 17 (Brussels sprouts), 17 (pepper), 17 (onions), 17 (asparagus), 26, 34, 52, 80, 83, 84, 86, 95, 105 (bottom illustration), 122 (both illustrations), 140, 167, 189, 192, 219, 229, 304, 305, 335, 379, 385. Jomphe M.—illustrator (Agriculture and Agri-Food Canada, Ottawa). Cover, spine, pages 17 (cauliflower), 47, 92 (all illustrations), 97 (both illustrations), 100 (all illustrations), 124, 143, 145, 152 (top illustration), 162, 165, 174, 223, 226, 235 (bottom illustration), 251, 275, 279, 373.

Sources of illustrations

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Millspaugh, C.F. 1887. American medicinal plants. An illustrated and descriptive guide to the American plants used as homeopathic remedies: their history, preparation, chemistry, and physiological effects. Boericke and Tafel, New York, NY, USA. 2 vols. ca. 80 p. (irregularly paginated). Page 352. Nicholson, G. (Editor). 1885. The illustrated dictionary of gardening. Vol 1. L. Upcott Gill, London, UK. 544 p. Pages 17 (broccoli), 43, 64, 105 (top illustration), 106, 109, 115 (top illustration), 146, 149, 153, 157, 178 (both illustrations), 183 (bottom illustration), 185, 188, 216, 232, 285, 298, 367. Nicholson, G. (Editor). 1886. The illustrated dictionary of gardening. Vol II. L. Upcott Gill, London, UK. 544 p. Pages 112, 203, 234 (top illustration), 356. Nicholson, G. (Editor). 1887. The illustrated dictionary of gardening. Vol III. L. Upcott Gill, London, UK. 537 p. Pages 324, 358. Nicholson, G. (Editor). 1889. The illustrated dictionary of gardening. Vol IV. L. Upcott Gill, London, UK. 608 p. Page 130. Parsons, F.T. 1899. How to know the ferns. Charles Scribner’s Sons, New York, NY, USA. 215 p. Page 265. Vilmorin-Andrieux, M.M. 1885. The vegetable garden. John Murray, London, UK. 620 p. Pages 11 (potato, mushrooms), 16 (cucumber, beans, parsnip, rutabaga, radishes), 17 (lettuce, celery, spinach), 24, 29, 31, 33, 37, 38, 54, 55, 57, 58, 65, 67, 70, 73, 76, 81, 82, 83 (bottom illustration), 85 (both illustration), 93, 99, 101, 103, 108 (both illustrations), 111, 115 (bottom illustration), 119, 120, 126, 132, 133, 134, 137, 138, 148, 150, 151, 152 (bottom illustration), 159, 168, 172, 176, 177, 180, 181, 183 (top illustration), 186, 194, 197, 199, 205, 207, 211, 214, 231, 234 (bottom illustration), 235 (top illustration), 237, 240, 243, 246, 247, 254, 256, 259, 261, 283, 288, 290, 295, 299, 301, 303, 306, 309, 310 (both illustrations), 313, 315, 316, 318, 319 (both illustrations), 321, 326, 327, 331, 332, 333, 338, 339, 346, 348, 351, 354, 355, 359, 361, 362, 366, 376, 383. Yuzyk, L.—illustrator (Agriculture and Agri-Food Canada, Ottawa). Page 271.

Introduction What is a vegetable? In 1887 this question became the subject of a famous legal battle, when a merchant launched an attempt to evade paying duties on tomatoes imported into New York from the West Indies. The tax had been collected under a tariff act that levied duties on vegetables. In 1893 his argument that tomatoes were exempt because they really were fruits was carried to the Supreme Court of the United States of America. The Supreme Court ruled as follows: “Botanically speaking, tomatoes are the fruit of a vine, just as are cucumbers, squashes, beans and peas. But in the common language of the people, whether sellers or consumers of provisions, all these are vegetables, which are grown in kitchen gardens, and which whether eaten cooked or raw, are, like potatoes, carrots, parsnips, turnips, beets, cauliflower, cabbage, celery and lettuce, usually served at dinner in, with, or after the soup, fish or meats, which constitute the principal part of the repast, and not, like fruits generally, as dessert.” Webster’s Third International Dictionary defines a vegetable as “an edible part of a plant (as seeds, leaves, or roots) that is used for human food and usually eaten cooked or raw during the principal part of a meal rather than as a dessert …” Although some vegetables may be consumed both during the principal part of the meal and as dessert (e.g., sweet potatoes and sweet potato pie), most vegetables are distinguished by their predominant use during the main part of the meal. It is usually possible to distinguish vegetables from plants categorized as edible “herbs,” “spices,” or “condiments” by the use of the latter in small amounts to impart flavor, aroma, and seasoning to foods. For example, the herbs parsley and basil are usually eaten in small quantities, although they may be used in considerable amounts like vegetables in some ethnic dishes. A second book (Culinary Herbs, Small 1997) addresses herbs and most condiment plants of Canada and the northern United States. If a particular “vegetable” is not treated in this book, it will likely be found in the culinary herb book. In some cases, one or more species of a genus are treated in our vegetable book, and one or more species of the same genus are dealt with in the culinary herb book. Thus for Allium, species such as A. cepa (onion) are treated as vegetables because of their predominant use as such (this is not to deny that dehydrated onions are used as a spice or seasoning). Other species such as chives (A. schoenoprasum) and garlic (A. sativum) are treated as herbs.

2


Sometimes one part of a plant is used as a vegetable and another part as a herb or spice. Thus Brassica juncea provides both the vegetable spinach mustard (treated in the present volume) and the condiment mustard seed (treated in Small 1997); and Petroselinum crispum furnishes the vegetable turnip-rooted parsley and the herb parsley. Other examples of species treated here as vegetables for which information on use as a herb will be found in Small (1997) include Capsicum annuum (pepper), Foeniculum vulgare (Florence fennel), and Apium graveolens (celery). Usually where one species is used both as a vegetable and a herb, different cultivars, sometimes different subspecies, are used for the vegetable and for the herb.

The evolution of vegetables Agriculture is believed to trace back no more than 10 000 years. Before that time, as hunter-gatherers, people relied on plants for much of their subsistence diet. Several progressive stages can be recognized in the domestication and cultivation of crops. With respect to any particular crop, the stage of progression does not necessarily depend on when that crop was first used or cultivated historically. Some wild plants, such as sugar maple, continue to provide a satisfactory wild harvest. The only vegetable of this kind treated in this book is fiddleheads. Without any care at all, a plant cannot be said to be “cultivated,” but just how much care is needed is arbitrary. One can observe even today how some undeveloped societies provide minimal care such as weeding to wild plants, which they periodically harvest. Planting seeds in prepared soil is generally what is understood by cultivation. Sometimes the word “domesticated” is used to describe both plants and animals under the care of humans, but scientists concerned with domestication generally reserve the word to designate plants and animals that have been selected genetically. Sometimes cultivated plants are basically wild plants, unaltered genetically from related plants growing free in nature. Usually, however, cultivated food plants differ from their wild ancestors. The term cultigen is often used to designate domesticated plants that differ significantly from their wild ancestors. Cultigens may have cultivars, i.e., named distinct races that are useful for particular purposes. The wild plant from which a cultivated plant has been selected may continue to grow in nature, although generally it does not provide as satisfactory a harvest. Sometimes the wild ancestor has been exterminated, so that the plant is only known in cultivation. Sometimes there are three kinds of plants for a particular crop species: a cultigen, its wild ancestor, and wild-living escapes from cultivation. For each vegetable treated in this book, these distinctions are clarified, as far as information is available. Although there are as many as 300 families of higher plants, vegetables (and indeed other kinds of crops) have not been selected equally from these families.

Introduction

Families providing many vegetables

3

The following families are especially important with respect to vegetables (those treated in this book are listed): Chenopodiaceae: beet, garden orach, good King Henry, spinach, Swiss chard Compositae (Asteraceae): cardoon, chicory, chop suey green, dandelion, endive, globe artichoke, great burdock, Jerusalem artichoke, lettuce, salsify, scorzonera Cruciferae (Brassicaceae): numerous brassicaceous vegetables, garden cress, radish, rocket, sea kale, upland cress, watercress Cucurbitaceae: angled loofah, smooth loofah, bitter melon, bottle gourd, several cucumbers, pumpkins and squashes, wax gourd Leguminosae (Fabaceae): alfalfa, common bean, faba bean, groundnut, lima bean, mung bean, pea, scarlet runner bean, soybean, yard-long bean Solanaceae: eggplant, peppers, potato, tomato Umbelliferae (Apiaceae): carrot, celeriac, celery, Florence fennel, parsnip, skirret, turnip-rooted parsley

Scope of this book Crops included

All the vegetables included, except for ostrich fern, are obtained from flowering plant species. We have included a few plants that are generally not known as vegetables in Canada, which can be grown in this country. Most of the unusual vegetables treated are obtainable in Canadian garden catalogs. Seeds of a few are available only from some of the larger foreign seed catalogs but can easily be imported by mail. Two of the vegetables, fiddleheads from the ostrich fern and groundnut, are wild plants native to Canada. Fiddleheads are presently obtained by harvesting wild stands and are already a significant vegetable crop in Canada. The possibility of cultivating both is under active exploration. Many other wild plants of Canada are eaten on occasion as vegetables (Szczawinski and Turner 1980). The possibility of their development as vegetables has been noted (Turner 1981), but they are not treated in this book. Most of the vegetables described here originated in the Old World, although an appreciable number arose in Central and South America. Canada simply has not been a site of origin of any commercially significant vegetable species, and so a treatment of vegetables of interest in Canada necessarily requires examination of international information.

Crops excluded

We have excluded all food plants that cannot be considered to be vegetables grown either commercially or popularly in home gardens in Canada. We had sought a precise definition of vegetable that would help us in deciding what to include and exclude. Eventually we decided simply to include plants commonly known as vegetables. We have excluded most grains that might be used in the same way as vegetables. We have also excluded most pulses (plants of the legume family the fruit or seeds of which are consumed by humans), such as lentils. However, peas and beans are widely understood to fall within

4


the term vegetables and we have included vegetable soybean (although it is mostly grown as an oilseed). The following lists some excluded pulses and grains growable in Canada that are sometimes consumed as vegetables. (Note: where a genus is treated in this book, its foreign species of economic interest as vegetables are usually mentioned, and this information is not repeated here.) Pulses: – Chick pea, garbanzo bean (Cicer arietinum L.) – Fenugreek (Trigonella foenum-graecum L.) – Grass pea (Lathyrus sativus L.; can be poisonous!) – Lentil (Lens culinaris Medic.) – Peanut (Arachis hypogaea L.) – Silky lupine (Lupinus sericeus Pursh; can be poisonous!) Grains: – Barley (Hordeum vulgare L.) – Buckwheat (Fagopyrum esculentum Moench) – Oats (Avena sativa L.) – Wild rice (Zizania aquatica L.) – Wheat (Triticum species) Excluded also are two classes of nonflowering plants, the fungi (notably including the mushrooms) and the algae (notably including the seaweeds). One species of cultivated mushroom (Agaricus bisporus (Lge.) Sing.) is economically important as a vegetable in Canada. Information on cultivating mushrooms is available from Tape (1975), Stamets and Chilton (1983), and Chang (1991). The interested reader should also note the journal Mushroom World (Official Publication of the Canadian Mushroom Growers’ Association). Some specialty mushrooms are also cultivated in Canada, particularly the oyster mushroom (Pleurotus ostreatus in the wide sense) and shitake (Lentinula edodes (Berk.) Pegler). Harvesting of wild mushrooms has become a multimillion-dollar industry in Canada, especially in British Columbia, where three wild mushrooms are collected in commercial amounts (de Geus et al. 1992). Substantial amounts of the pine mushroom (Tricholoma magniverale (Peck) Redhead) are exported to Japan; morels (Morchella species) and chanterelles (Cantharellus cibarius Fr.) are exported to Europe. Several species of seaweeds are harvested from the wild, and a few are cultivated. Although most are economically important for the substances they yield rather than their value as vegetables, several are eaten as vegetables. Perhaps the most notable of these is dulse (Palmaria palmata (L.) O. Kuntze), which is popular as a vegetable in eastern maritime Canada. Information on edible seaweeds distributed along Canadian shorelines is found in Schofield (1989), Szczawinski and Turner (1980), Turner (1975), and Small et al. (1997). Information on the economic value of Canadian seaweeds is provided in Bird and

Introduction

5

van der Meer (1993). A general review of seaweeds as vegetables is given in Madlener (1977). Potential vegetables

The choice of vegetables that deserve attention in the future is not limited to those mentioned in this book. Hundreds more species are used as vegetables in other countries. Although most are unsuitable for the Canadian climate and many are wild plants that require considerable crop development, several of these vegetables probably have excellent potential because of the unique properties they possess. Vegetables that might be of interest in Canada, at least as garden oddities, are listed in the table below. Several vegetables listed are from the Andes, where plants have evolved considerable cold tolerance, as is needed in Canada. About 500 years ago, the Incas farmed dozens of fruits and vegetables, which they had domesticated. Unfortunately, except for the potato and lima bean, most have been ignored by modern agriculture. By comparison with most modern crops, they require considerable improvement by breeding and have limitations that must be overcome, such as a need to grow where day and night are about equal as in the tropics. Some vegetable oddities not mentioned elsewhere in the book but potentially growable in Canada. Scientific name Arracacia xanthorrhiza E.N. Bancr. Canna edulis Ker-Gawl

Common name Peruvian carrot, Arracacha Edible canna

Chaerophyllum bulbosum L. Mirabilis expansa R.&P. Oxalis tuberosa Mol.

Turnip-rooted chervil Mirabilis Oca

Petasites japonicus (Siebold & Zucc.) Maxim. Polymnia sonchifolia Poepp. & Endl. Salicornia europaea L.

Butter bur

Scolymus hispanicus L.

Spanish oyster plant Chinese artichoke Mashua

Stachys affinis Bunge = S. sieboldii Miq. Tropaeolum tuberosum R.&P. Ullucus tuberosus Caldas Vigna angularis (Willd.) Ohwi & Ohashi

Parts eaten, and where cultivated Inca root crop grown in high Andes Andean tuber crop, also grown in Australia for starch Grown in Europe for its bulbs Andean tuber crop Andean root crop grown in Mexico and New Zealand Grown in Japan for its edible leaf stalks

Yacon

Andean root crop

Glasswort

Young shoots harvested in NW Europe Roots (rarely) harvested as vegetable in Europe Grown in Eurasia for its tubers

Ulluco Adzuki bean

Root crop grown in Andes Inca root crop grown in high Andes Used in Old and New Worlds as bean sprouts and for young pods

6


Use of plant parts as vegetables1 Different parts of plants furnish vegetables, and it is useful to know what choice is possible. For example, one might wish to grow different root crops in rotation, to avoid buildup of disease organisms, or one might wish to specialize in leafy salad vegetables. The following list may be useful for those wishing to choose crops grown for the same plant part. Etiolated shoots (above-ground stem “blanched” or whitened, by blocking out sunlight, which increases taste and tenderness). Belgian endive,2 cardoon, celery,2 dandelion,2 rampion, sea kale2 Flowers. Angled loofah, chicory, chop suey green, dandelion, pumpkin (Cucurbita pepo), scarlet runner bean, squash (Cucurbita pepo), smooth loofah Flower heads. Artichoke (globe), broccoli,2 cauliflower2 Fruits (pods, gourds). African cucumber,2 angled loofah, bitter melon, bottle gourd, Chinese cucumber,2 common bean, corn,2 cucumber,2 currant tomato,2 eggplant, faba bean, okra, pea,2 pepper,2 pumpkin, scarlet runner bean, smooth loofah, squash, tomato,2 wax gourd, yard-long bean, zucchini2 Leaves (including swollen leafstalks). Amaranth, arugula,2 beet, cabbage, celery,2 collards, chicory,2 Chinese cabbage,2 Chinese kale, Chinese mustard,2 Chinese savoy,2 chop suey greens, corn salad,2 dandelion,2 endive,2 fiddlehead, Florence fennel,2 garden cress,2 good King Henry, kale, leek, lettuce,2 Malabar spinach, mizuna,2 mustard greens,2 New Zealand spinach, onion,2 orach, parsley,2 purslane,2 radicchio,2 rampion, sea kale,2 spinach, spinach mustard, Swiss chard, upland cress,2 winter purslane,2 watercress,2 water spinach Seeds. Common bean, faba bean, lima bean, pea,2 scarlet runner bean, soybean Seedlings (seed sprouts). Alfalfa,2 faba bean, garden cress,2 leek,2 lima bean,2 mung bean,2 onion,2 radish,2 soybean2 Stems (branches, shoots and spears). Amaranth, asparagus,2 Brussels sprouts,2 cardoon, chop suey greens, good King Henry, hop, Malabar spinach, New Zealand spinach, orach, spinach, water spinach Swollen ground-level stems. Celeriac,2 kohlrabi j Underground parts (roots, tubers, bulbs). Beet, carrot,2 great burdock, groundnut (Apios), Jerusalem artichoke, onion,2 parsnip, potato, radish,2 rampion,2 rutabaga, salsify, scorzonera, skirret,2 sweet potato, turnip, turnip-rooted parsley

1 2

Plant parts are defined botanically and technically, so classification may seem odd in a few places. For example, corn kernels are technically fruits, and peas are seeds. Can be eaten raw.

Introduction

7

Preserving germplasm of heritage vegetable varieties Conservation of crop genetic resources is a large and important topic, but only a few remarks will be made here; for a highly readable introduction, see Hoyt (1992). Germplasm refers to the genetic endowment carried by a race. The term is usually used with reference to the genetic constitution of economic and related wild plants (less so with animals). Plants that harbor valuable germplasm are most commonly preserved as seeds in gene banks; they are also preserved as frozen tissues, living collections in gardens and arboreta, and most importantly as wild plants in nature, sometimes in specially designated reserves. Gene “banks” are aptly named, because some of the seeds they contain have genes capable of improving the value of crop plants by millions, even billions, of dollars. In light of the current crisis of vanishing wild areas and the plants they sustain, preserving germplasm resources is extremely important. International networks have been established, such as the International Board for Plant Genetic Resources, centred in Rome, Italy. As well, many countries have national genetic resources systems for plants. The United States has a National Plant Germplasm System, with about 400 000 collections stored in 26 locations around the country. This system, the most important national genebank in the world, started modestly in 1898 with a cabbage variety introduced from Russia. Canada’s national system is centred in the Plant Gene Resources of Canada (part of Agriculture and Agri-Food Canada). It has a seed collection in Saskatoon of more than 100 000 accessions. There is also a clonal collection of more than 2500 accessions (for vegetatively reproduced fruit crops such as apples and strawberries) at Harrow, Ontario, and specialized research collections at various research stations across Canada. Like the United States, Canada is an important international contributor to genetic preservation. An appreciable cost is associated with every stock that is maintained in a gene bank, and although so-called “obsolete” cultivars are often maintained, they frequently vanish without trace. This loss can be far-reaching, because modern breeders often sacrifice taste and novelty for such considerations as resistance to damage during long-distance transportation. Old-time varieties of vegetables are commonly too tender to withstand mechanical harvesting and ripen irregularly, providing a long-term harvest. Such qualities, although desirable in the home garden, are not valued by large-scale producers, who have concentrated on high-yielding, disease-resistant hybrids. Fortunately, some organizations have developed to save the older, heirloom varieties, many of which are maintained by home gardeners as a family keepsake; however, these plants are in constant danger of extinction when these gardeners die. These organizations may simply offer seeds of heritage varieties, much like most commercial seed companies. More typically they also provide the opportunity for one to participate in the maintenance of particular varieties, to engage in societal activities, and to receive publications. The best known of these organizations in North America are noted below.

8


In the United States, The Seed Savers Exchange was founded in 1975 by Kent Whealy (Ponte 1990). This organization lists 4000 varieties of vegetables for exchange and maintains 8000. It is one of the very few sources of the Black Krim tomato (usually various shades of brown or purple). Those wishing to participate in the seed exchange service may write for further information to: Seed Savers Exchange, Rural Route 3, Box 239 Decorah, IA 52101, USA. Importation of vegetable seeds into Canada is generally not difficult but some seeds (notably for corn and faba beans) require importation permits. Also, weed seed regulations such as those covering chicory (see discussion under this crop) might prohibit importation. If in doubt, write for information to: Permit Office, Plant Protection Division Canadian Food Inspection Agency 59 Camelot Drive Nepean, ON K1A OY9, Canada. In Canada, an organization similar to the American Seed Savers Exchange began in 1984 under the name the Heritage Seed Program. Although still widely known by this title, its current corporate name is Seeds of Diversity Canada. This is Canada’s principal society dedicated to the preservation of heirloom varieties, and the work is conducted on a volunteer basis. The organization currently has over 2000 members, and over 1200 varieties of plants, including many vegetables. Notable vegetables in the collection are Pruden’s Purple tomatoes (which are actually pink) and B.C. blue potatoes (actually violet when baked). Those wishing to participate in the seed exchange service may write for further information to: Seeds of Diversity Canada, P.O. Box 36, Station Q, Toronto, ON M4T 2C7, Canada.

Diseases and pests It has been estimated that, even with plant protection programs, the average losses caused by diseases and pests in Canada are 15.5 and 12.5%, respectively, and that reduced yield and quality from pest damage in the field may be exceeded by lossses in storage (Howard et al. 1994). On average, diseases and pests may cause the loss of about half of the value of vegetable crops. Diseases of vegetables are due to a wide variety of microorganisms, including bacteria, actinomycetes, fungi, viruses, and virus-like pathogens. Pests include not only insects but also a variety of other animal groups (often confused with insects by non-specialists), especially nematodes, mites, centipedes, millipedes, symphylans (centipede-like animals), sowbugs, and pillbugs, as well as birds and mammals. Although diseases and pests are extremely important to vegetable culture in Canada, little information on these aspects is presented in this book. Diseases and Pests of Vegetable Crops in Canada (Howard et al. 1994)

Introduction

9

is an extremely thorough and competent manual that deals with these problems

Recommended reading on vegetables (All literature cited is listed in the Bibliography.) Bennett 1982, Buishand et al. 1986, Cole 1991, Coleman et al. 1991, Facciola 1990, Halpin 1978, Harrington 1978, Herklots 1972, Hinton 1991, Janick and Simon 1990, Nicholson et al. 1975, Nonnecke 1989, Richardson 1990, Schneider 1986, Simmonds 1976, Splittstoesser 1990, Szczawinski and Turner 1980, Tindall 1983, Yamaguchi 1983.

World Wide Web Internet links Numerous World Wide Web sites deal with vegetables and related research, marketing, gardening, and other topics. The most important Canadian agricultural sites which have relevance to vegetables are Agriculture Research Branch (http//:res.agr.ca/) and Agriculture and Agri-Food Canada Electronic Information Service (http://aceis.agr.ca/) including Agriweb (http://aceis.agr.ca/agriweb/agriweb.htm). A comprehensive source of information on agricultural topics, including vegetables, is the United States Department of Agriculture web site (http://www.usda.gov/). A world internet list is the World Wide Web virtual library of Agriculture (http://ipm_www.ncsu.edu/cernag/cern.html). Some other notable sites available on the web at the time this book was prepared are as follows (many of these provide links to additional sites of interest): General sites

Associations/producer organizations

Gardening and Agriculture http://mail.databits.com/garden.html Canadian and American Agriculture Links http://www.spectramedia.com/agrinet/links/ Internet directory for botany http://herb.biol.uregina.ca/liu/bio/idb.shtml Internet directory for botany/Ethnobotany http://www.helsinki.fi/kmus/botecon.html#ethno Internet directory for botany/Crops http://www.helsinki.fi/kmus/botecon.html#crops Internet directory for botany/ Gardening http://www.helsinki.fi/kmus/bothort.html Canadian Agricultural Associations http://www.experts.ca/agriasso.html Canadian Produce Marketing Association http://www.cpma.ca/ Ontario Fruit and Vegetable Growers Association http://www.ofvga.org/ Foodnet http://foodnet.fic.ca/welcome.html

10

Climate zone maps


American Associations http://agrinet.tamu.edu/groups/gfruitvg.htm

Canadian climate zones http://www.ICanGarden.com/zone.htm U.S. Dept. Agriculture climate zones http://www.dicom.se/fuchsias/usdazones.html Climate zone map for Europe http://www.klippo.se/nilsson/eurozoner.html

Economics/markets and growing

Gardening information

Fresh Produce Market Information http://www.sbed.com/secag1.htm Farm Business Management Information Network http://fbminet.ca/index.htm Vegetable Guide from Singapore (includes vegetables covered in this book) http://www.sci-ctr.edu.sg/ssc/publication/veg/contents.html Phillipine Vegetables (includes vegetables discussed in this book) http://www.tribo.org/vegetables/sampler.html Home Horticulture of Vegetables http://www.msue.msu.edu/cgi-bin/impsrch/mod03?vegetable Gardening catalogs (includes Canadian sites) http://www.cog.brown.edu:80/gardening/cat.html Gardening catalogs http://trine.com/GardenNet/CatalogCenter/mocatmst.htm Discovery Channel Garden links http://eagle2.online.discovery.com/DCO/doc/1012/world/garden/ g arden060496/weblinks.html Garden Web http://www.gardenweb.com/ The Plant Tracker http://www.axis-net.com/pfaf/

Home use and preparation of vegetables

Oasis garden network http://www.produceoasis.com/default.htm

Research

Agricultural Research Service Phytochemical and Ethnobotanical Databases http://www.ars-grin.gov/~ngrlsb/ Gateway to the New Crop Resource Online Program http://www.hort.purdue.edu/newcrop/ Unusual Vegetables http://csf.colorado.edu/sustainability/plants/vegies.html

World Wide Web (WWW) links change, move, and may become defunct. As the WWW is a transient, volatile medium, addresses may become inaccurate. It is important to utilize the sophisticated search engines and web crawlers available on the WWW. Even if many of the above URLs become dated, their titles furnish key words for a search. On the whole, the World Wide Web is a valuable addition to information concerning vegetables obtained from printed sources,

Introduction

11

especially for recently generated information. There are numerous illustrations that are available, usually in color, and this pictorial capacity of the internet is very impressive. We certainly urge those who have not yet become acquainted with the World Wide Web to do so, as this is an efficient, cheap, and entertaining mode of communication that is becoming the world’s central storehouse of information. However, it is clear that, as of this writing, most of the knowledge that has been accumulated concerning vegetables is not yet available on the internet. Moreover, the quality and reliability of internet information concerning vegetables is variable. Scholarly, academic work is usually recognizable by its nature and is relatively trustworthy. Sites that are maintained by governments, universities, and other major research organizations tend to produce reliable information.

The vegetable economy of Canada

Important vegetables of Canada The following notes are based on Coleman et al. (1991), who provide an authoritative economic analysis of vegetables in Canada. The vegetables for which Statistics Canada published production and farm value statistics for the period 1989–1995 are given in the table that begins on page 12. Potatoes, mushrooms, and tomatoes represent about two-thirds of the total value of Canadian vegetables. Potatoes

Potatoes (ranked first in dollar value) are the most important vegetable crop in Canada, representing about 40% of the total value of Canadian-grown vegetables. About half of the potato crop originates in Atlantic Canada, particularly in New Brunswick and Prince Edward Island. Canada is a net exporter of both fresh and seed potatoes. Frozen french fries and potato chips represent substantial industries in Canada.

Mushrooms

Mushrooms represent the second most valuable vegetable crop in Canada, with production concentrated in Ontario and British Columbia. About half the mushrooms consumed in Canada, mostly canned mushrooms, are still imported, but over the last decade domestic production has increased. Exports of fresh mushrooms are mainly from British Columbia, destined for the United States and Japan. Tomatoes are the third-ranking Canadian-produced vegetable crop. Tomatoes for processing have represented over 80% of total output in recent years, with fresh field tomatoes and greenhouse tomatoes accounting for approximately 10% and 5%, respectively. All regions of Canada produce fresh tomatoes, but processed production is concentrated in southwestern

Tomatoes

12


Regional and total farm values for major Canadian vegetables ($ million)

1

Asparagus Beans Beets Cabbage Carrots Cauliflower Celery Corn Cucumbers3 Lettuce Mushrooms Onions Parsnips Peas Peppers Potatoes Radishes Rutabagas Spinach Tomatoes3 Totals

Atlantic Provs. — — 0.4 3.4 3.6 1.2 — 1.5 1.2 1.0 4.1 4 — 0.2 — — 229.5 — 4.1 — 2.8 253.0

19905


— — 0.4 3.7 2.6 1.5 — 1.0 1.5 1.0 4.7 6 — 0.3 — — 170.3 — 4.4 — 2.2 193.6

19917

Asparagus Beans Beets Cabbage Carrots

1989

— — 0.4 3.6 4.7

Que. 1.3 7.8 1.5 14.4 15.4 6.0 5.4 16.6 7.5 15.5 4.1 4 6.0 — 5.8 3.4 63.4 1.2 3.9 0.6 12.7 192.5

Ont. 5.7 6.1 2.3 11.0 17.0 9.7 5.5 41.1 32.8 3.7 85.4 19.6 0.6 11.6 7.1 41.8 1.7 5.7 1.2 118.5 428.1

Prairie Provs. 0.1 — 0.2 1.9 3.8 0.4 0.5 2.2 3.2 — 27.6 2.5 0.4 — — 96.3 — 0.9 — 0.7 140.7

B.C. 0.4 1.8 0.4 3.1 4.5 3.3 1.9 4.2 5.5 5.2 37.7 2.9 0.3 4.1 0.3 21.0 0.5 0.9 0.2 8.2 106.4

Canada2 7.5 17.5 4.8 33.8 44.4 20.5 13.2 65.6 52.5 25.4 159.0 31.0 1.5 28.1 10.8 452.0 3.4 15.5 2.0 143.0 1131.5

1.8 6.3 1.7 13.3 22.3 6.2 4.4 18.7 7.6 13.2 4.7 6 6.6 — 5.7 3.9 49.2 1.6 4.5 0.7 16.4 188.8

5.4 5.7 3.1 10.8 14.5 13.9 2.2 45.1 26.9 5.3 76.0 13.6 0.6 15.2 13.7 42.1 1.4 7.5 1.1 104.8 408.9

0.2 — 0.2 2.7 5.9 0.6 0.3 3.3 7.1 — 22.4 2.4 0.6 — — 95.0 — 0.8 — 1.1 142.6

0.4 1.8 0.4 2.9 3.3 2.9 1.1 3.2 5.8 5.3 45.7 3.5 0.2 3.5 0.3 16.9 0.4 0.8 0.3 8.2 106.9

7.8 15.1 5.8 33.4 48.6 25.1 7.9 71.3 49.0 25.0 153.6 26.1 1.6 30.4 17.8 373.5 3.4 18.0 2.0 132.9 1048.3

1.4 7.0 1.8 13.3 27.2

4.0 6.4 2.7 7.6 17.8

0.2 — 0.4 2.8 5.5

0.4 1.5 0.5 2.3 4.7

6.0 17.3 5.7 29.6 60.0

Introduction

13

19917

Cauliflower Celery Corn Cucumbers3 Lettuce Mushrooms Onions Parsnips Peas Peppers Potatoes9 Radishes Rutabagas Spinach Tomatoes3 Totals

Atlantic Provs. 1.9 — 2.1 0.4 0.9 4.6 8 — 0.3 — — 167.8 — 3.9 — 1.2 191.8

Que. 5.7 6.5 18.1 5.1 15.6 4.6 8 12.9 — 6.9 3.5 54.4 2.3 5.5 1.0 7.3 200.1

Ont. 7.1 4.9 38.4 7.9 5.0 74.4 19.8 0.6 8.2 14.8 41.6 1.6 3.6 0.7 75.7 342.8

Prairie Provs. 2.2 0.3 3.4 1.5 — 21.6 3.1 0.6 — — 95.3 — 0.8 — 0.2 137.9

B.C. 1.8 0.9 2.9 0.9 4.5 44.6 2.0 0.2 3.2 0.4 23.2 0.7 0.7 0.7 1.4 97.5

Canada2 18.8 12.6 64.9 15.8 25.9 149.8 37.8 1.7 24.5 18.7 382.3 4.6 14.4 2.3 85.8 978.5

199210


— — 0.5 3.0 3.0 1.5 — 1.7 1.8 1.7 2.5 11 — 0.3 — — 145.1 — 5.0 — 3.0 169.1

1.4 5.7 1.6 11.2 29.9 6.0 8.5 20.4 7.2 20.0 2.5 11 13.6 — 7.5 2.8 49.9 1.7 7.4 1.3 19.0 217.6

5.4 8.6 1.9 10.3 19.0 8.8 3.6 33.1 28.6 7.9 76.9 16.4 0.4 11.9 10.6 42.0 1.4 4.0 0.7 94.2 385.7

0.2 0.9 0.4 2.4 5.7 2.2 0.4 2.0 9.3 0.4 20.2 2.9 0.6 3.8 0.1 116.4 0.6 0.9 0.2 2.4 172.0

0.5 1.4 0.5 3.0 6.1 2.7 1.0 3.7 10.4 5.7 45.8 1.8 0.2 2.4 0.5 22.1 0.8 0.7 0.6 10.7 120.6

7.5 16.6 4.9 29.9 63.7 21.2 13.5 60.9 57.3 35.7 147.9 34.7 1.5 25.6 14.0 375.5 4.5 18.0 2.8 129.3 1065.0

199312

Asparagus Beans Beets Broccoli Brussels Sprouts Cabbage Carrots Cauliflower Celery Corn

— 0.1 0.6 3.6 0.9

1.2 5.6 2.0 10.4 0.9

5.5 6.8 1.2 4.1 0.7

0.2 0.8 0.4 1.0 —

0.6 0.9 0.6 3.7 2.3

7.5 14.2 4.8 22.8 4.8

4.0 5.8 1.6 — 1.5

14.7 24.6 6.1 6.8 20.1

8.6 18.9 6.1 3.8 25.0

3.1 6.2 2.2 0.4 2.2

2.5 5.7 3.0 0.8 3.1

32.9 61.2 19.0 11.8 51.9

14


199312

Cucumbers3 Lettuce Mushrooms Onions Parsnips Peas Peppers Potatoes Pumpkins Radishes Rutabagas Shallots Spinach Squash Tomatoes3 Totals

199412

Asparagus Beans Beets Broccoli Brussels Sprouts Cabbage Carrots Cauliflower Celery Corn Cucumbers3 Lettuce Mushrooms Onions Parsnips Peas Peppers Potatoes Pumpkins Radishes Rutabagas Shallots Spinach Squash Tomatoes3 Totals

199515

Asparagus Beans Beets Broccoli

Atlantic Provs. 2.0 1.5 2.0 13 — 0.6 — — 271.8 — — 4.4 — — 0.1 3.5 304.0

Que. 8.2 21.1 2.0 13 14.8 3.6 4.9 3.7 79.9 0.7 2.4 5.7 2.3 1.5 1.2 32.2 276.6

Ont. 29.2 4.3 85.2 26.2 0.5 7.2 10.7 55.6 — 1.4 3.9 3.8 0.5 — 121.3 430.5

Prairie Provs. 7.8 0.3 25.9 3.5 0.4 3.1 0.1 126.7 0.1 0.6 1.3 1.2 0.3 0.4 1.4 189.6

— — 0.6 5.0 0.7

1.3 7.6 2.4 10.0 0.8

4.8 11.1 1.9 7.0 1.1

0.2 0.9 0.3 1.2 —

0.7 0.9 0.6 4.5 1.6

7.0 20.5 5.8 27.7 4.2

3.7 6.3 1.5 — 1.7 2.1 1.7 2.2 14 1.6 0.5 — — 282.3 — — 4.8 — — — 4.1 318.8

1.2 — 7.9 7.0 19.2 8.3 19.4 2.2 14 — 3.6 4.4 4.0 66.9 0.8 2.4 — 2.6 1.3 1.4 30.6 205.3

11.5 14.4 7.5 3.1 29.0 30.1 6.2 97.8 11.9 0.4 7.6 12. 64.2 3.3 1.6 5.1 3.5 0.3 3.5 120.9 460.4

2.7 6.5 2.4 0.5 4.4 8.5 0.4 28.0 2.7 0.4 2.9 — 149.6 0.2 0.7 0.9 1.4 0.3 0.4 1.0 216.5

2.6 6.0 2.6 1.2 3.9 11.1 3.4 38.6 2.7 0.2 3.4 0.5 30.2 1.0 0.8 0.8 0.9 0.7 1.1 14.1 134.1

21.7 33.2 21.9 11.8 58.2 60.1 31.1 168.8 18.9 5.1 18.3 17.1 593.2 5.3 5.5 11.6 8.4 2.6 6.4 170.7 1335.1

— 1.7 0.6 3.6

1.1 6.4 2.1 9.2

6.5 9.3 1.7 6.4

0.3 1.2 0.5 1.3

0.7 1.1 0.7 5.5

8.5 19.8 5.6 26.7

B.C. 10.5 3.0 36.6 3.5 0.2 1.8 0.5 24.1 0.2 0.8 0.8 — 0.7 1.1 11.5 118.5

Canada2 57.7 30.2 151.7 48.0 5.3 17.0 15.0 558.1 1.0 5.2 16.1 7.3 3.0 2.8 169.9 1319.2

Introduction

15

199515

Brussel Sprouts Cabbage Carrots Cauliflower Celery Corn Cucumbers3 Lettuce Mushrooms Onions Parsnips Peas Peppers Potatoes Pumpkins Radishes Rutabagas Shallots Spinach Squash Tomatoes3 Totals2

Atlantic Provs. 0.7

Que. 0.9

Ont. 1.2

Prairie Provs. —

B.C. 1.2

Canada2 4.0

2.0 2.6 2.1 — 1.4 0.2 1.2 3.8 16 1.5 0.3 1.5 — 254.0 0.4 — 3.8 — — 0.5 0.4 282.3

14.2 28.5 7.0 8.0 17.2 8.2 23.9 3.8 16 14.6 3.3 3.7 5.6 72.6 0.9 2.6 8.4 3.6 1.8 1.5 34.8 283.9

12.9 13.8 9.4 5.3 28.4 36.7 6.6 109.0 15.7 0.5 9.5 12.1 54.0 2.4 2.9 4.9 3.7 0.6 5.2 120.3 479.0

4.3 10.0 2.8 0.6 5.3 8.4 0.5 27.3 3.6 0.7 2.5 — 167.2 0.5 0.9 1.1 1.5 0.7 0.6 1.6 243.4

2.9 6.4 1.6 1.2 3.9 11.9 4.2 48.2 3.3 0.2 2.2 1.0 38.6 1.2 0.9 0.8 0.9 0.7 1.9 18.6 159.8

37.5 63.8 22.8 15.1 56.2 67.7 36.4 192.2 38.8 5.0 21.6 18.8 586.3 5.3 7.2 19.1 9.7 3.7 9.7 178.7 1460.2

1 Based

on Anonymous 1991c. 1989–91, values are as reported by Statistics Canada; Canadian totals occasionally exceed regional totals because some provincial statistics are confidential. For 1992–95, values were obtained by summing the regional values, which slightly underestimates the Canadian totals. 3 Includes greenhouse crops for tomatoes and cucumbers. Due to changes in methodology, the pre 1992 estimates for greenhouse cucumbers and tomatoes are not directly comparable with post 1992 estimates. 4 Separate figures not available for Maritimes and Quebec; their cumulative value was $8.2 million. 5 Based on Anonymous 1992h. 6 Separate figures not available for Maritimes and Quebec; their cumulative value was $9.4 million. 7Based on Anonymous 1993b. 8 Separate figures not available for Maritimes and Quebec; their cumulative value was approximately $9.2 million. 9Taken from Anonymous 1994a. 10Based on Anonymous 1995a. 11Separate figures not available for Maritimes and Quebec; their cumulative value was $5.0 million. 12Based on Anonymous 1995b. 13Separate figures not available for Maritimes and Quebec; their cumulative value was $4.0 million. 14Separate figures not available for Maritimes and Quebec; their cumulative value was $4.4 million. 15Based on Anonymous 1997. 16Separate figures not available for Maritimes and Quebec; their cumulative value was $7.8 million. 2 For

Ontario and greenhouse production is mainly found in Ontario and British Columbia. However, more than half the tomatoes consumed in Canada are imported. Cucumbers

Cucumbers are grown both in the field and in greenhouses. Field-grown cucumbers represent about 40% of the farm value of

16


production, with production centred in Ontario and Quebec. Pickle manufacture is appreciable in Canada. Greenhouse produce, concentrated in Ontario, is sold completely on the fresh market. More than one-third of all cucumbers consumed in Canada are imported. Corn, green peas, and beans

Several crops are produced mostly for processing, including corn, green peas, and beans. About 80% of corn and beans and over 50% of green peas are produced in Ontario and Quebec. Most of these crops are raised domestically.

Root crops

Parsnips, rutabagas, radishes, beets, and carrots all produce edible roots. These crops are produced in all regions of Canada, but mostly

in Ontario and Quebec. More than half the beets and about one fifth of the carrots are processed; the remaining crops are produced mainly for the fresh market. Except for radishes, the domestic supply is responsible for most Canadian consumption. Cole crops

Cole crops include cabbage, cauliflower, Brussels sprouts, and broccoli. Cabbage and cauliflower are grown particularly in central

Canada, where Quebec is the leading cabbage producer and Ontario is the leading cauliflower producer. Broccoli is produced in Ontario, Quebec, and British Columbia, with significant production also in the Maritime Provinces, Manitoba, and Alberta. Most Brussels sprouts are processed, whereas most of the broccoli crop is marketed fresh. About 5% of cabbage and 10% of cauliflower are processed. About half of cole crops consumed in Canada are grown domestically.

Introduction

Lettuce

Celery

Peppers

Onions

17

Lettuce is grown in central Canada, particularly Quebec, and in British Columbia, but is not processed (i.e., incorporated into any frozen or

cooked products or into fresh salad preparations) in Canada. Only about 20% of lettuce consumed in Canada is produced in this country. Celery is produced mostly in central Canada, particularly in Ontario, and in British Columbia. About 5% of Ontario’s celery is processed. About 25% of celery consumed in Canada is produced in this country. Peppers are produced in central Canada and in British Columbia. About a quarter of Ontario’s peppers are processed. About a third of peppers consumed in Canada are produced domestically. Onions are widely grown in Canada, except in the Atlantic Provinces. Ontario is responsible for more than 60% of national production. About 50% of onions consumed in Canada are produced here. However, domestic production is mainly of yellow onion; most of the milder Spanish onion need to be imported because the climate in much of Canada is not suitable for its growth.

Asparagus

Asparagus is produced mainly in Ontario (75%), with appreciable production also in Quebec and British Columbia. Most processing occurs in British Columbia. Only about 10% of asparagus consumed in Canada is produced domestically.

Spinach

More than half of Canadian commercial spinach is grown in Ontario, with significant production also in Quebec and British Columbia. Only about 15% of spinach purchased in Canada is produced domestically.

Regional production The most important province of Canada for vegetable production is Ontario, which accounts for about 40% of the national farm value. The five most important vegetable crops of Ontario are tomatoes, mushrooms, potatoes, corn, and cucumbers. Atlantic Canada accounts for about 20% of the national farm value for vegetables; potatoes represent about 90% of this value. Quebec produces about 20% of Canada’s vegetable farm value, the most

18


important crops being potatoes, corn, lettuce, and carrots. British Columbia produces about 10% of the value of Canada’s vegetables; the largest crops are mushrooms, potatoes, tomatoes, cucumbers, and lettuce. The Prairie Provinces account for about 10% of the value of vegetable production, with potatoes and mushrooms as the most important crops. Within the provinces of Canada, some regions have become well known for production of particular crops, as shown in the following table (based on Nonnecke 1989). Based on the 1986 Census of Agriculture, there were 11 800 farms growing vegetables in Canada, of which 40% were in Ontario and 26% Major vegetable-producing regions in Canada Province Ontario

Region Holland/Thedford Grand Bend Leamington Essex–Kent Toronto region

Quebec N.B. P.E.I. Nova Scotia Manitoba Alberta B.C.

Alliston Montreal La Pocatière Atlantic Atlantic Atlantic Prairie Prairie Lower Fraser Valley

Major crops Carrot, onion, lettuce Celery, cauliflower Greenhouse tomato and cucumber, onion, pepper, asparagus Processing tomato, peas, sweet corn Broccoli, cauliflower, cabbage, Brussels sprouts, mushroom, salad crops Potato Carrot, onion, mixed vegetables Potato, rutabaga Potato Potato, rutabaga Carrot Potato, onion, cabbage, rutabaga Potato, carrot, cabbage Lettuce, cabbage, cauliflower, broccoli, carrot, potato

in Quebec. The average area devoted to vegetable production was 15.8 ha (39 acres). Of the farms, 48% were specialized vegetable farms with an average of 26.3 ha (65 acres) devoted to vegetables. Large producers were responsible for much of the overall production: about 25% of vegetable producers accounted for 80% of all vegetable sales. The 1991 Census of Agriculture (note Read 1994 for analysis of vegetable data) produced a similar picture. A total of 123 000 ha of land were planted with vegetables, 5% more than in 1986. Ontario devoted 62 500 ha to vegetables, while Quebec had 37 000 ha. Sweet corn, green peas, and tomatoes accounted for 55% of the vegetable area. There were 10 700 farms reported growing vegetables. The average size of a farm growing vegetables was 62 ha. In 1991, each Canadian consumed an average of 11 kg of tomatoes and 11 kg of lettuce, roughly equivalent to 58 average-size tomatoes and 16 heads of iceberg lettuce. Because of the long, cold winters in most of Canada, greenhouses are important, not only for producing vegetables but also for growing bedding plants for home vegetable gardeners. The 1991 Census of Agriculture showed that Canada had about 5000 commercial

Introduction

19

greenhouses, mainly in Ontario, Quebec, and British Columbia. Ontario is the province with the most important greenhouse culture. Canada’s greenhouse-grown vegetables often exceed $1 000 000 in value annually, and the same is true for vegetables raised in greenhouses for sale as bedding plants (Anonymous 1991a; Anonymous 1994b). Total greenhouse area was about 8.5 million square metres, 17% more than in 1986. About half the greenhouse area was filled with flowers, 30% with vegetables, and 20% with vegetable seedlings and other products (Read 1994). The top three greenhouse vegetables are tomatoes, cucumbers and lettuce.

Vegetables and crop diversification in Canada Crop diversification is a principal current concern for Canadian agriculture. Agricultural production in Canada is based primarily on a handful of plant species, mostly cereals. However, hundreds of species are grown as crops in Canada, and there is considerable potential to develop these more fully and to use others. It is important to identify new crop species that will permit economic diversification, and to develop new cultivars that are suitable for Canadian conditions and meet specific market requirements. Four “pillars” have been identified as essential to the Canadian Agri-Food sector, namely market responsiveness, self reliance, regional diversity, and environmental sustainability (Anonymous 1990d). The development of new Canadian crops is important in each of these respects. New crops require research, development, production, and marketing. Of the categories of crops, vegetables are not the best candidates for diversification. In general, there are now so many human food plants that forages and fodders for livestock represent better possibilities for development of alternative crops. Even more likely to find new markets are crops that yield industrial and medicinal products. Nevertheless, some possibilities exist for diversifying with vegetable crops. For many vegetables (as for other crops), plant diversification can be achieved either by growing unusual or new varieties of familiar crops, or by finding nontraditional markets, or sometimes by growing vegetables out of their normal season. We offer a brief analysis of market potential for each vegetable treated in this book. For purposes of plant diversification, it is often for the least known crops that the need for information is greatest. The foremost Canadian vegetable, the potato, represents 40% of the value of the Canadian vegetable market; not surprisingly, an enormous literature is available. By contrast, relatively little information exists on the possibilities of Canadian cultivation of some unusual vegetables for ethnic markets in Canada. Few Canadians have ever heard of such vegetables as celtuce, gobo, Chinese winter melon, cardoon, globe artichoke, African cucumber, Chinese okra, bitter melon, turnip-rooted chervil, good King Henry, sea kale, arugula, skirret, corn salad, vegetable oyster, water celery, water spinach, witloof chicory, scorzonera, yard-long bean, and French spinach. Most of these have been grown

20


in Canada, but in small quantities. Such specialties have limited potential, but, because of the loyalty of consumers to ethnic and distinctive crops, markets are often stable and dependable and therefore of interest to enterprising farmers and marketers. Expert marketing is important for all new food crops. Consumers are conservative and reluctant to try unfamiliar foods, particularly vegetables for which they already have considerable choice. Except for the relatively stable ethnic markets, the introduction of each new vegetable needs careful marketing. The vegetable should be sold only in its optimal condition, and recipes and guidance on its use provided. The growing success of wild vegetable harvests such as wild rice and fiddleheads shows that Canadian consumers can be persuaded.

Plant classification and plant names

Natural and artificial classifications In this book we provide considerable detail on the classification and scientific names of plants. Classifications are important because they help people to identify plants and retrieve information and make it easy to understand the relationships of the plants being classified. In most cases we have presented so-called “natural classifications,” which are based on genetic and evolutionary relationships. Economic plants, however, are often classified only on the basis of selected economic characteristics, and, while such “artificial classifications” usually do not reflect natural relationships, they are often useful. For example, classifications of cultivars on the basis of earliness of flowering, or fruit color, may not reflect genetic relationships, but if one is interested in finding early maturing varieties with a certain fruit color, such a classification is useful. Although much research has been done on the classification of economic plants, in most cases knowledge is incomplete. Sometimes it is not even clear whether the basis of classification is natural or artificial. We have tried to make clear the basis of classifications of most of the genera we have included. It can be very important to have a natural classification, because this reflects closeness of genetic relationships, and sometimes it is useful to know what vegetables are related. For example, root crops susceptible to a given soilborne disease usually should not be rotated with related crops. They too may be susceptible, with the result that the disease organism may accumulate in harmful concentration. People who have allergies to one kind of plant may also react to related plants in the same genus or even in the same family. The ultimate objective of classifications is simplicity. Unfortunately, simplicity has not always been achieved, sometimes because not enough effort and study has yet gone into the classification, and sometimes simply because some groups of plants are so complex. The brassicaceous vegetables (those belonging to the genus Brassica) exemplify an extremely variable and difficult group.

Introduction

21

The importance of nomenclature Plant nomenclature is important in ways that most people do not appreciate. Because both common and scientific names of plants are often ambiguous, the literature can easily be misinterpreted (this is not a question of whether something is correctly identified or not, but a question of what one is talking about). For example, “pumpkins” are fruits of four different species: Cucurbita argyrosperma, C. maxima, C. moschata, and C. pepo. The name C. argyrosperma came into common use only in 1989 and replaced the previously widely used name C. mixta. The common names are even more confusing; three of the species have varieties called “winter squash,” two have “gourds,” and one has varieties called “summer squash.” If the classification and terminology of such groups are not clearly understood, they can be easily confused. Because the ecological, agricultural, and economic properties of these species differ, their correct names must be available, so that the literature can be interpreted correctly. The “correct” scientific name of a plant (be it at the genus, species, subspecies, or varietal levels) is governed by codified, internationally accepted rules. Unfortunately, the operation of some of these rules has resulted in changes of names; in some cases it has not yet been authoritatively determined which name should be used. Experts in plant classification are sometimes needed to determine which names are synonymous (equivalent), and when the same given name is being used to denote different plants. As a result, interpretation of names used in the literature can be misleading. In many cases we have listed synonymous, older, discarded names because they are often encountered in the literature. Like scientific names, common names also can be very difficult to interpret. For example, in North America broccoli refers to an annual green-sprouting form known in Britain and Italy as calabrese. In Britain, the term broccoli is sometimes used to denote cauliflower. The word corn has the same meaning as maize (Indian corn) in North America, but in much of the Old World “corn” means wheat, or sometimes simply the predominant local cereal. “Gobo” is an alternative name for both great burdock and okra. Rutabagas are similar to turnips, and some users of these names confuse the two. Pumpkins are often squashes. Most of the time the way names are being used can be correctly interpreted, but sometimes, even after detective work, it just isn’t clear what a writer means or what a garden catalog is selling. A relatively unimportant but annoying feature of common (vernacular) names is the different spellings and forms of words that are encountered. For examples, Brussels sprout and Brussels sprouts; the alternative names for okra: “gumbo," “gobo," and “gombo”; and the alternative names for purslane: “pusley” and “pursley." Names transliterated into English from foreign languages are often encountered in several versions; e.g., as pointed out in the treatment of Oriental cabbages, the following are alternative names for Chinese mustard: bok choy, bok choi, pak choy, pak choi. Other examples will

22


be found in the list of common names we present for each species treated in detail.

What is a variety? The word “variety” is ambiguous, because it has both a scientific and a common meaning. Scientifically, variety denotes a formal classification category, which is lower than a subspecies. For example, Daucus carota var. sativus denotes the common cultivated carrot. However, in common speech the word variety refers to a kind, which has been taken up by horticulturists who use the term “cultivar” to designate cultivated varieties by descriptive names or phrases rather than by Latin words. By convention, cultivar names are either shown in single quotation marks or after the abbreviation cv. (for cultivar), following the scientific name. For example, Daucus carota ‘Spartan Sweet’ (or Daucus carota cv. Spartan Sweet) is a cultivar of the common carrot. However, it is permissible to simply refer to Spartan Sweet, when it is clear what species is under discussion. Sometimes cultivars are grouped into classes, and although these class names can be recognized by the formalized categories of “scientific” nomenclature, this is rarely done. For example, some informal classes of the common carrot are Chantenay and Nantes, each of which may have many recognized cultivars. The formal, Latin, scientific system of nomenclature is compatible with the system described here for denoting cultivars and cultivar groups. Sometimes classifications combine elements of both the Latin and informal systems of classification (see, for example, the treatment of carrot).

French names French names are important for Canadian vegetables, not only because French is an official language of Canada, but also because, in many parts of the English culinary world, French names are used for vegetable dishes to impart a sense of haute cuisine. Even some English seed catalogs specializing in vegetables give French names (e.g., The 1993 Gourmet Gardener published in Leawood, Kansas). We have given at least one principal name in French. Generally, we have followed Boivin (1992), occasionally Croteau (1991), which present recommended French names to follow in Quebec. A few names were taken from Richardson (1990). In some cases, especially where a wild form of a vegetable plant can be harvested in Canada, names have been added from Quebec floristic treatments (e.g., Marie-Victorin 1964). For some vegetables that are sufficiently rare in Canada that an established name is unavailable in Quebec, we have followed Organ (1960) and international French dictionaries (e.g., Mansion et al. 1972–1980); however, some entries can be misleading. Vilmorin-Andrieux (1885) is an excellent source of French names for vegetables used in France a century ago, and indeed today. We have used this now somewhat archaic book only when other sources were unhelpful.

Introduction

23

Format used for presentation of scientific and common names As an example of the format adopted, consider the information for Cichorium and for the first species of this genus examined, endive (C. endivia): Under Cichorium, the following is presented: 1. Compositae (Asteraceae) 2. Sunflower family 3. Composées, famille de la marguerite Entry 1 gives the Latin scientific name of the family to which Cichorium belongs, and the alternative family scientific name if available (nine plant families have alternative names). Entry 2 presents the English common name for the family. Entry 3 provides (a) a French version of the Latin family name (Composées, following Grisvard et al. 1964). Currently in Quebec Latin family names are used, as in English (e.g., Compositae). However, in international French the Latin names have been given French suffixes; (b) a French family common name (famille de la marguerite), usually following Fleurbec (1978, 1981, 1983). Under Endive, the following is presented: 1. Scientific (Latin) name: Cichorium endivia L. 2. English common name: endive 3. Also: escarole 4. French common name: scarole (f) 5. Also: chicorée scarole, chicorée endive 6. [To avoid: escarole (Boivin 1992). Chicorée endive (from Organ 1960) is international. Scarole and chicorée scarole are accepted in Quebec. The French word endive designates C. intybus (sometimes called French endive) discussed later. By contrast, the English word endive designates C. endivia.] Entry 1 supplies the correct scientific name (for many of the vegetables discussed in this book, additional scientific names that are commonly encountered are also given). Entry 2 gives the principal English name (occasionally names) used in Canada. Entry 3 gives additional English names (irrespective of whether or not they are used in Canada). Entry 4 gives the principal name or names used in Quebec (f = feminine, m = masculine). Entry 5 gives additional French names (irrespective of whether or not they are used in Canada). Entry 6 in square brackets gives supplementary information (such additional information is also occasionally presented for English names).

Abelmoschus Okra Malvaceae Mallow family Malvacées, famille de la mauve

Genus notes Abelmoschus comprises 6–20 species of annual or perennial herbs, depending on taxonomic treatment. Many species of this genus have been included in the closely related Hibiscus. Indeed, okra has been placed in Hibiscus by some authors (as H. esculentus L.). Charrier (1984) described recent advances in the classification of Abelmoschus, and Bates (1968) discussed the taxonomy of the cultivated species. The genus is found in tropical Africa and Asia. Several species are cultivated, most notably A. esculentus. Other important species include A. manihot (L.) Medic., commonly known as aibika, the leaves of which are used as a vegetable; and A. moschatus Medic., musk mallow, which has leaves used as a vegetable and musk-scented seeds employed in making a perfume.

Names Scientific (Latin) name: Abelmoschus esculentus L. Frequent scientific synonym: Hibiscus esculentus L. English common name: okra Also: gumbo, gobo, gombo, lady’s-finger French common name: gombo (m) Also: okra

Description and taxonomy Okra is an annual herbaceous plant, apparently only known as a cultigen. The most closely related wild relative is A. tuberculatus Pal & Singh of northern India. Other wild relatives occur in Ethiopia, the upper Nile in Sudan, and West Africa. A second cultigen, provisionally called “Guineen” okra, has been described from parts of Africa (Martin 1982). Okra was used in Egypt from at least A.D. 1200 and its use spread into the eastern Mediterranean and subsequently to India. African

Abelmoschus (okra)

25

slaves introduced it to the Americas (Yamaguchi 1983), and the French brought it to the Mississippi delta in the 17th century. It is still an important part of Creole cooking of Louisiana (Halpin 1978). Okra is commercially grown in climates warmer than Canada’s. However, recently developed cultivars have allowed home garden production in parts of Canada. The fruiting structure of the genus Abelmoschus is technically a capsule. However, the term “pod” is commonly used to describe the fruit in agricultural literature and this practice is followed here.

Uses Okra pods are used fresh as a cooked vegetable and are added to soups, stews, and casseroles. The pods are also frozen or dehydrated for later use. Okra should be picked and consumed while still unripe, as it becomes coarse and fibrous when fully mature. Young okra pods can be batter- or stir-fried and are important in Creole cooking for “gumbo” soups. In parts of the southern United States, the pods are dried and used in the winter. The pods can be pickled. The seeds can be used similarly to dried beans. Young okra leaves can be used as cooked greens (Halpin 1978; Charrier 1984). In addition to its use as a vegetable, dehydrated okra is used as a flavoring and emulsifier in food processing, commonly in salad dressing. In India, okra seeds are used as a coffee substitute (Hedrick 1972). Okra stems have also been used for paper and cordage (Grieve 1978; Nonnecke 1989). Example recipes

Baked okra and ground beef casserole (Morash 1982) Barbara Spiegel’s Cape Cod gumbo (Schneider 1986) Fried okra (Morash 1982) Okra and lamb stew (Morash 1982) Okra curry (Buishand et al. 1986) Okra ratatouille (Richardson 1990) Okra salad (Buishand et al. 1986) Okra soup (Morash 1982) Tomato and okra stew (Ornish 1990) Shellfish gumbo (Morash 1982)

Importance Okra is used in the warmer parts of Africa, the Mediterranean, and the Americas (Charrier 1984). Some cultivars developed in the United States produce 7 t/ha. The major production areas in North America are the southeastern United States, Texas, and California. Seed production is concentrated in southwestern Arizona (Nonneke 1989). In Canada, okra production is restricted to home gardens and is usually started indoors. Some okra may be encountered in Canadian market gardens for local consumption.

26


Cultivation notes Soil

Maximum production occurs on deep, well-drained soils. Okra tolerates a pH range of 6.0–7.5. The plant does poorly in waterlogged soils. A side dressing of nitrogen, usually applied midway through the season, is beneficial (Yamaguchi 1983; Nonnecke 1989).

Climate

Okra is a tender crop, unable to tolerate low temperatures for long, and is susceptible to frost. Commercial production of okra requires sustained warmth, with optimum temperatures of 21–30°C. Okra also requires high moisture levels.

Propagation and cultivation

Okra is propagated by seeds, which have hard coats that prevent prompt germination. In commercial production, seeds are sometimes subjected to concentrated sulfuric acid for 2–3 h. Alternatively, seeds are soaked in a water bath at 45°C for 1.5 h (Nonnecke 1989). Because of the short growing season in Canada, it is beneficial to start the plants indoors to increase eventual production of fruit pods (Nonnecke 1989).

Harvest and storage

Okra has indeterminate growth; fruit production continues throughout the growing season as long as pods are not allowed to mature. The young pods are hand-harvested when they reach maximum quality, generally at 6–10 cm long. If the pods are longer, they become fibrous and tasteless. The pods are picked by lightly twisting them off the stem. Care must be taken because they bruise easily. Removal of the young pods encourages the plant to produce new flowers and pods. Okra pods respire at high rates. Commercially, the pods are immersed in cool water to reduce their temperature quickly to 10°C; they are then stored at 95% relative humidity. The pods store for a week at 2–13°C.

Example cultivars

Annie Oakley, Blondy, Clemson Spineless, Perkins Mammoth Long Pod. Bettencourt and Konopka (1990) listed institutions in various countries conserving okra germplasm. Genetic resources in okra were discussed by Hamon et al. (1991). Facciola (1990) provided an extensive description of okra cultivars available in the United States.

Additional notes Okra seeds have been found to have a more balanced amino acid protein pattern than soybeans, although the protein content is lower. Sulfur-containing amino acids are limited but may be compensated for by combining okra seeds with other ingredients, such as sesame seeds and wheat flour. Baking tests showed that the addition of 5% okra to wheat flour yielded acceptable loaves with a distinctive flavor (Halpin 1978).

Abelmoschus (okra)

Curiosity

27

Okra came to the Americas with the slave trade, and indeed names applied to okra are often linked to the African slave trade. The name okra originates from the word nkruman, from twi, a language of the Gold Coast of Africa. The name gumbo originates from the word ngumbo, used by slaves from Angola.

Problems and potential Okra is a minor crop commercially in Canada, with little potential for expansion because it is far better adapted to warmer climates.

Selected references Bates 1968; Charrier 1984; Amor 1992.

Allium Onion crops Liliaceae Lily family Liliacées, famille du lis

Genus notes Opinion varies on the size of the genus Allium, with estimates ranging from 400 to more than 500 species (for a recent review, see Hanelt et al. 1992). The plants are biennial or perennial, mostly with bulbs, and are strongly odorous when bruised. The genus is widely distributed throughout the warm-temperate and temperate zones of the northern hemisphere. The economically important species are mostly Old World, although chives (A. schoenoprasum L.) has circumpolar distribution and is native to Canada. Several other species are native to Canada. Wild leek (A. tricoccum Ait.) is found in rich moist woods from Manitoba east to Nova Scotia, excluding Prince Edward Island. Wild leek is considered by Gibbons (1962) to be the sweetest and best of the native onion bulbs. Erichsen-Brown (1979) noted that this plant was baked in ashes by native Canadians. Moerman (1981) recorded that the Chippewa used boiled wild leek as an emetic, the Iroquois ate it as a spring tonic and antihelmintic (anti-worm medicine) for children, and the Cherokee consumed it for colds and used it as a mild laxative. Canada garlic (A. canadense L.) is found in thickets, woods, and meadows from Ontario to New Brunswick. Gibbons (1962) noted that Canada garlic is sweet and palatable after boiling. This wild garlic has proven so popular in Gatineau Park, Que., near Ottawa, that its collection has been forbidden. Because the plant has a 7-year cycle from seed to seed, overharvesting threatened its survival. The taxonomic relationships of Allium are controversial. This genus has been historically placed in the Liliaceae. Some botanists have included it in the Amaryllidaceae on the basis of inflorescence structure. More recently, it has been segregated as a distinct family, Alliaceae (Hanelt 1990). We have chosen to follow the traditional, broader family concept that includes the genus in the Liliaceae. Generally a clear distinction exists between species of Allium employed as vegetables and those used as herbs and seasonings. The vegetable species discussed below include A. ampeloprasum, leek; A. cepa, common onion; and A. fistulosum, Japanese bunching onion. Those used primarily as herbs and seasonings are described in a companion volume (Culinary Herbs, Small 1997) and include A. sativum, garlic; A. schoenoprasum, chives; A. tuberosum, garlic chives or Chinese chives; and A. ×proliferum, Egyptian onion.

Allium (onions and leeks)

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In addition to the Allium species discussed below, others are important in Asia. One notable species is A. chinense G. Don, known as rakkayo, which is native to central eastern regions of China. Today it is widely cultivated in China and Japan where it is mostly consumed as pickles; it is sometimes exported to North America (Toyama and Wakamiya 1990). The International Board for Plant Gene Resources lists all designated seed base collections for Allium. The two centres with global collections are the Institute of Horticultural Research, Wellesbourne, UK, and the National Seed Storage Laboratory, Fort Collins, USA (Astley 1990).

Leek

Names Scientific (Latin) name: Allium ampeloprasum L. Frequent scientific synonym: Allium porrum L. English common name: leek French common name: poireau (m)

Description and taxonomy Leek is a biennial herbaceous plant that is grown as an annual. It has both wild and domesticated forms. Van der Meer and Hanelt (1990) presented a formal infraspecific classification of the leeks. Most cultivated leeks have a distinctive appearance. The part of the plant of interest as a vegetable occurs just above the root, as an elongated stemlike structure composed of the overlapping lower leaves. The commercial form is often whitish, because the grower protects the basal part of the plants from light. In the following discussion, this key part is referred to as a “pseudostem.” The first three forms of the domestic leek (subsp. ampeloprasum) noted below are most widely recognized. European. This type has a relatively short and thick pseudostem. Turkish. This form has a relatively long, thin pseudostem and is grown in Turkey, Bulgaria, and northern Egypt. Kurrat. Labeled as A. kurrat Schweinfurt ex Krausse by some authors, this type lacks a pronounced pseudostem and is grown in the Near East, mainly in Egypt. Other, relatively poorly known forms that have been recognized include the following:

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Pearl onions. Known as A. ampeloprasum L. var. sectivum Lued. by some authors, this type produces small bulblets. These onions are used domestically in Germany and, until 1982, were produced commercially in The Netherlands. The plants do not have pseudostems. The bulbs are used mostly for pickling. Great-headed garlic. Known as A. ampeloprasum L. var. ampeloprasum, by some authors, this type produces about six big cloves during its second season of growth. The robust plants have a garliclike odor. The cloves are used like garlic, and the leaves may also be consumed as a condiment. This plant is used in Egypt but is also cultivated in the eastern Mediterranean, western Asia, and the United States. Elephant garlic belongs to this type (Yamaguchi 1983). “Taree Irani.” This type is grown near Teheran, Iran, for its green leaves. “Poireau perpétuel.” This form is used in France, Algeria, and Greece for its leaves. “Prei anak.” This vegetatively propagated leek is grown commercially in West Java at about 1000 m altitude. A moderate-sized leek plant develops from a vegetative shoot and then produces up to 10 side shoots. The vegetable is firmer than European leeks. Several wild taxa have been recognized. The wild form of subsp. ampeloprasum (a subspecies that also includes some cultivated plants) is characterized by small, helmet-shaped or spherical bulblets appressed to the mother bulb. This form occurs in the Mediterranean region from Portugal and northwest Africa to Turkey and Iran. Some isolated variants from western Europe (var. babingtonii (Borr.) Syme, and var. bulbiferum Syme) have been placed in subsp. ampeloprasum. Subspecies truncatum (Feinbr.) Kollm., found in Israel, has bulblets that develop on horizontal stems up to 10 cm long. Subspecies iranicum Wendelbo, found in western Iran, also has bulblets that develop on stolons. The leek was cultivated more than 4000 years ago by the ancient Egyptians. Later the Romans introduced leeks throughout Europe. Its use in North America is more recent; it was first cultivated in the southern United States in 1775 (Halpin 1978; Hedrick 1972). The leek has never gained the popularity in North America of the other major cultivated species of Allium, namely onion and garlic.

Uses Leek has a milder flavor than either onion or garlic and makes an excellent substitute for them. Leeks may be eaten raw, alone or mixed in salads. They are also steamed, fried with other vegetables, or boiled. Leeks are added to soups, quiche, stews, and casseroles (Halpin 1978; Buishand et al. 1986). The large bulbs of elephant garlic, some exceeding 500 g, have a more delicate flavor than garlic (Allium sativum) and are mild enough to be served steamed as a vegetable.


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Example recipes

Arugula, potato, and leek soup (Schneider 1986) Baked scallops and leeks (Morash 1982) Chanterelle feuilletés with vegetable julienne (Levy 1987) Chicken and leeks Oriental (Hamilton 1982) Green vichyssoise (Owen 1978) Leek and barley soup (Morash 1982) Leek and mushroom crêpes (Levy 1987) Leek and pork pie (Morash 1982) Leek mornay (Tudge 1980) Leek tartlets (Morash 1982) Leekaroni and cheese (Hamilton 1982) Mushroom and leek crêpes (Ornish 1990) Soup of winter vegetables and dried mushrooms (Schneider 1986) Spinach, leek, and pumpkin pancakes (Levy 1987) Stewed fava beans and leeks with lemon (Schneider 1986) Stir-fried shrimp and leeks (Morash 1982)

Importance The European Economic Community typically produces over 600 000 t of leeks annually (Rabinowitch and Brewster 1990a). By contrast, Canada produces only a few thousand tonnes annually, while importing more than it produces. For example, in Canada in 1991, 1385 t of domestic and 2765 t of imported leeks were unloaded at 10 major Canadian wholesale markets (Anonymous 1992a); in 1992, 1996 t of domestic leeks were unloaded in these markets (Anonymous 1993a). Most of Canada’s leeks are grown in Quebec, with smaller amounts in Ontario, British Columbia, and other provinces. Dietz (1991) reported that elephant garlic is being grown in British Columbia. More than 20 farmers, some planting more than 1 ha, are growing elephant garlic on a commercial scale. The bulbs can sell for three times the value of garlic bulbs.


Leeks require rich, loamy, well-drained soils. The pH may range from 6.0 to 8.0. The leek is more responsive to nitrogen than other onions, which encourages heavy foliage formation (Yamaguchi 1983; Nonnecke 1989).

Climate

The leek is more frost tolerant than many other cultivated onions. However, cold temperatures may cause undesirable premature flowering. Leeks grown consistently at 15°C form flower stalks. The tendency to form bulbs, which is undesirable, is also controlled by temperature and occurs between 15°C and 18°C. Supplemental irrigation promotes uninterrupted growth (Nonnecke 1989). Plants grown from seed must be planted as early as possible in Canada.

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Leeks are propagated by seeds and are best started indoors in Canada to compensate for the short growing season. Leeks are planted in trenches about 10 cm deep. As the leeks grow, soil is gradually placed around the base of the plants up to the place where the leaves diverge. This practice results in blanching (whitening) and a tastier, more tender pseudostem (Halpin 1978).

Harvest and storage

Commercial production of leeks is labor intensive. Harvesting is carried out after the pseudostems reach 2.5 cm in diameter, when they may vary from 15 to 25 cm in length. Leeks are more desirable when tender, before the stalks get overly thick. At harvest the plant is undercut and the roots and leaves trimmed. Leeks can remain in storage for 2–3 months if kept near 0°C with 90% humidity (Nonnecke 1989). The bulbs of elephant garlic may not mature until the second season.

Example cultivars

Early season: Titan. Main season (summer/fall): Kalima, Splendid. Late season and storage types: Alaska, Longina. (Some leeks, such as Alaska, are winter-hardy.) Elephant garlic is sold as cloves in some Canadian garden catalogs. Malo and Bourque (1992) discussed recent tests of cultivars in Montreal. Bettencourt and Konopka (1990) listed institutions in various countries conserving leek germplasm. Facciola (1990) gave an extensive description of leek cultivars available in the United States.

Additional notes Curiosities

The Israelites complained to Moses of being deprived of Egytian leeks during their wanderings in the wilderness (Hedrick 1972). The Roman Emperor Nero demanded leek soup daily because he believed that leeks, being good for the vocal chords, would make his orations more distinct and sonorous. Tradition has it that the leek was instrumental in helping the Welsh defeat the Saxons in A.D. 640 after St. David ordered the Welshmen to distinguish themselves from the enemy by wearing leeks on their hats before going into battle. The Welsh now wear leeks on their headgear on St. David’s Day, and leeks were adopted as the national plant of Wales. Englishmen in Northumberland regard leek growing as a competitive sport; each tries to grow the largest leeks. Some men become so absorbed in this activity that their wives are called “leek widows” (Halpin 1978). Competition is fierce. Some competitors even sabotage or steal their rivals’ leeks at night. Some leeks have been enormous—the tallest was nearly 2 m and the fattest was 28 cm around (Dunphy 1992).


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Problems and potential Amor (1992) noted that leeks are generally grown on tiny parcels of land in Canada, which may be in part because they are not an important vegetable to many ethnic groups. Interest in the use of leeks has been traditionally from people of European descent. There is potential for increased production of leeks to offset the amount imported into Canada. With current interest in greater culinary experimentation, the use of leeks may increase.

Selected references Halpin 1978; van der Meer and Hanelt 1990; Dunphy 1992.

Common onion

Names Scientific (Latin) name: Allium cepa L. English common name: onion French common name: oignon (m)

Description and taxonomy Allium cepa is a biennial herbaceous plant grown as an annual. It is unknown in the wild but is presumed to have been selected in the Middle East and parts of Asia. It has a wide variation of bulb characteristics, reflecting extensive selection during domestication. The bulb is a storage organ responsible for vegetative (asexual) reproduction. It consists of condensed stem tissue bearing fleshy scale leaves with buds in the axils. The bulbs are usually globose to pear-shaped. Skin and flesh of the bulbs take many forms. Several older infraspecific classification schemes are complicated. Additional research is required to better understand the taxonomy of the onion. A simple division developed recently, recognizes three horticultural groups (Hanelt 1990; Rabinowitch and Brewster 1990a). Common onion group. This group is known by various scientific names (Allium cepa L. var. cepa, A. cepa L. subsp. cepa, A. cepa L. subsp. australe Trofim.). The bulbs are large and normally solitary, and the plants reproduce from seeds or seed-grown onion sets (transplants). These onions are cultivated in most regions of

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the world for dry onions, salads, and pickling. Great diversity still exists in the onion gene pool of this group in southwest Asia and in the eastern Mediterranean. Aggregatum group. Formal names for this group include A. cepa L. subsp. orientale Kazak. and A. ascalonicum L. of some authors. Included are forms with small bulbs that are in aggregated clusters generated by rapid Multiplier formation. Reproduction is almost exclusively onion vegetative, by offspring bulbs. Onions of this group are mainly grown in home gardens. They are popular in tropical areas because they resist bolting. The shallots are the only ones grown commercially to any degree. The so-called potato or multiplier onions (sometimes called A. aggregatum G. Don) have larger main bulbs and fewer offspring bulbs. They can be found in home gardens in Europe, western Asia, and North America. Ever-ready onion group. Sometimes known as A. cepa L. var. perutile Stearn, this group has prolific vegetative growth and lacks the dormant period of the other two groups. Bulbs and leaves can be used any time during the year, mainly for salads. Two cultivated hybrids occur between A. cepa and A. fistulosum, the Japanese bunching onion, discussed below. The wakegi onion, A. wakegi Araki, has been cultivated as a green salad onion for centuries in China, Japan, and southeast Asia (Hanelt 1990). This is considered by some to be part of A. ×proliferum (Hanelt 1990). It has sterile seeds and therefore reproduces only vegetatively (Inden and Asahira 1990). Allium ×proliferum (Moench) Schrad. includes the top onion, tree onion, Egyptian onion, and catawissa onion and has flowers that develop into bulbils (topsets). The topsets and young sprout leaves are eaten. Onions have been cultivated for more than 4000 years. They appear in pyramid wall carvings from the third and fourth dynasties of Egypt (2700 B.C.). The ancient Greeks and Romans used onions. Onions had reached most of Europe by the Middle Ages, and the Spaniards brought them to North America (Nonnecke 1989).

Uses Onion bulbs as well as the chopped leaves are used raw or cooked in many vegetable dishes to which they impart an added zest. Onions are boiled, fried, stewed, baked, creamed, roasted, and pickled. They are deep-fried as onion rings. Salad bars have greatly increased the per capita consumption of onions (Nonnecke 1989; Brewster and Rabinowitch 1990).


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Example recipes

Baked onion with dill butter (Levy 1987) Crêpes with peppers, onions, and peas in curry sauce (Levy 1987) Grandma Ziegler’s onion pie (Owen 1978) Hearty, thick onion soup (Owen 1978) Kidney with shallots (Morash 1982) Mrs. Culler’s onion dinner rolls (Morash 1982) Onions stuffed with spinach (Levy 1987) Onions stuffed with wild rice (Morash 1982) Pissaladière (onion pie) (Morash 1982) Plum tomatoes with shallot purèe (Levy 1987) Sweet-and-sour broth-braised onion rings (Morash 1982) Escalloped onions (Morash 1982)

Importance Onions are one of the world’s most important vegetables. World annual production often is about 25 000 000 t of onion bulbs, with an estimated value of US$5 billion (Rabinowitch and Brewster 1990a). Canada produces over 100 000 t annually. Onions are grown commercially in several provinces in Canada. Ontario produces more than all the other provinces together, but large amounts are also produced in Quebec. Although Canada grows more onions than it imports, substantial amounts are imported. Most of the imports are the milder Spanish onions, whose production is restricted in Canada because of the climate. Most imports are from the United States, but Mexico also provides significant quantities. Mexico is able to harvest onions year-round and is an important supplier from November to May. It may be noted that some onion statistics may include Japanese bunching onion (A. fistulosum).


Young onions are very fragile upon emergence. Therefore, the soil should be friable and free from weeds, stones, and debris. Well-drained muck soils are best for sowing. In Canada, muck soils are used to grow onions in Ontario (Bradford, Leamington, Brand Bend, and Thedford marshes) and in Quebec. In lighter sandy soils, which are drier and warmer, yield tends to be lower. Onions are slightly tolerant of acidic soils but grow best where the pH is 7.5–7.8. Onions require soil with high fertility (Anonymous 1988a; Nonnecke 1989).

Climate

Onions are a cool-weather crop, adapted to growth at temperatures between 13 and 24°C. Germination occurs between 10 and 35°C. High soil moisture is desirable because of the small root system. Onions are sensitive to photoperiod, and long days promote leaf growth, which is directly related to bulb growth. Early varieties require about 13 h of daylight for bulb initiation, late varieties about 16 h. In Canada, early seeding or transplanting is essential for good onion yields. For the most part transplants are used in Canada

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because of the short season. However, an unusually cool spring can cause normally nonflowering young onions to bolt, which prevents bulb production. In muck soils frequent irrigation is desirable to maintain uniform moisture throughout the growing season. If the water level remains above 60 cm below the soil surface, swelling of the bulb will cause unmarketable “thicknecks” (a condition where the onion fails to ripen normally and continues to develop leaf blades rather than forming a bulb). Irrigation is reduced 2–3 weeks before harvesting to allow ripening (Anonymous 1988b; Nonnecke 1989; Brewster 1990). Propagation and cultivation

Onions are propagated by seeds, sets, or transplants. Traditionally, commercial onions were grown in Canada from transplants started in the southern United States. As hybrids became popular, more and more onions were direct-seeded. Various single or multiple vegetable seeding drills have been used but with the advent of precision seeders, onions can now be sown exactly where desired, allowing for large harvestable yields of higher grade than previous seeding methods. Onion sets are obtained by sowing shallots, potato, or multiplier onions very thickly. Under crowded conditions the onions mature at a much smaller stage. Shallots develop individual bulbs, which are mostly used for home gardens; they produce a bulb much earlier than if sown from seed. The potato or multiplier onions form clusters of bulbs. Spanish-type onions are still mainly grown from transplants, which ensure earlier maturity, larger bulbs, and greater uniformity. Larger seedlings generally provide higher yields (Nonnecke 1989).

Harvest and storage

When the tops of storage onions start to bend over and dry out, the bulbs have reached maturity. Sprout inhibitors may be used at this time. The tops must bend over naturally to ensure that the neck area closes and dries out. Storage onions are undercut and allowed to dry on the soil surface when at least 50–60% of the tops are down. If the season is too damp, bulbs may have to be lifted and dried in storage, such as in tobacco kilns. Onions for sets are pulled and cured in late summer or early fall when the bulbs have reached 2 cm in diameter and while the tops are still green. Larger bulbs produce too many onion sets that will be prone to bolting when planted the following year (Nonnecke 1989; Rabinowitch and Brewster 1990b). Onions are generally stored in temperature-humidity controlled structures at 0°C and 60–70% humidity. These conditions inhibit bulb sprouting and root growth (Nonnecke 1989). Storage diseases are discussed by Maude (1990).

Example cultivars

Transplants (Spanish type): Riverside Sweet Spanish, Monarch. Cooking (seeded): Canada Maple, Norstar, Sentinel. Sets: Stuttgarter, Golden Mosque, Ebenezer. Pickling: Barletta, Pompeii Perla Prima, Silver Queen. Bunching: Southport White Globe.


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Onions are available in many interesting shapes, sizes, and colors of flesh. For example, Kelsae Sweet Giant is a spanish onion that has been grown to 3.368 kg in size, whereas Lucifer produces bloodred bulbs. Cultivars such as Southport White Globe are used for the production of green bunching onions. Pike (1986) dealt with onion breeding in depth. International standards for grading onion bulbs were discussed in Spanish onion Anonymous (1984a). Legault et al. (1988) described testing of varieties of large onions (over 7.5 cm in diameter) that were successfully seeded in Quebec. Production was as good as that of yellow onions. The authors concluded that direct seeding of these varieties by more growers could diversify the onion market in Canada and reduce the importation of Spanish onions. Onion variety trials were also recently conducted in Prince Edward Island (Stevenson and Cutcliffe 1991). Peters (1990) extensively discussed onion seed production. Bettencourt and Konopka (1990) listed institutions in various countries conserving onion germplasm. Facciola (1990) provided an extensive description of onion classes and cultivars available in the United States.

Additional notes Augusti (1990) discussed the therapeutic use of chemicals found in onion. Allicins and related disulfide compounds are mildly bactericidal. Onion compounds also lower blood sugar and lipids and decrease blood platelet aggregation. This finding supports popular ideas that onions are “good for the blood.” On the negative side, cases of dermatitis have been reported after handling of fresh and dehydrated onions (Mitchell and Rook 1979). Curiosities

Onions were highly revered by the ancient Egyptians, who used them in religious ceremonies (Hedrick 1972). Oaths of office were sworn over an onion by the Egyptians, who believed that the layers forming spheres within a sphere symbolized eternity. This reverence for the symbolic onion shape is also reflected in Byzantine architecture, which frequently has onion domes in religious structures. In the 18th century Captain James Cook refused to sail to remote areas of the Pacific until each of his crew members had consumed about 14 kg (30 lb) of onions within 3 days, as a precaution against scurvy. Similarly during the American Civil War, General Ulysses S. Grant sent the following wire to the War Department during the summer of 1864: “I will not move my army without onions.” The next day three trainloads of onions were dispatched. Onions were considered essential for controlling dysentery and other ills (Nonnecke 1989).

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Pigments obtained from the scales of yellow onions were used in 19th century Germany to color Easter eggs.

Problems and potential Onions are susceptible to a variety of diseases (Crête et al. 1981). Onion maggot and thrips are major insect pests of onions. Weeds are a serious problem in the spring. Yellow nut sedge (Cyperus esculentus L.) is one of the most serious weeds on muck soils in Ontario. Amor (1992) noted that the new herbicide Prowl was used for the first time in 1991 and proved extremely helpful in onion production. There is potential for increased growth in onion production to reduce the amount of imported onions.

Selected references Legault et al. 1988; Anonymous 1990c; Brewster 1990; Brewster and Rabinowitch 1990; Hanelt 1990; Rabinowitch and Brewster 1990a, 1990b; Stevenson and Cutcliffe 1991.

Japanese bunching onion

Names Scientific (Latin) name: Allium fistulosum L. English common name: Japanese bunching onion Also: Welsh onion, spring onion, two-blade onion, green bunching onion, green tail, Chinese small onion, Spanish onion (not to be confused with forms of Allium cepa that develop large bulbs, commonly known as Spanish onion in Canada). French common name: ciboule (f) In France: oignon de Strasburg (Inden and Asahira 1990), ail fistuleux, oignon d’hiver (Schultze-Motel 1986).

Description and taxonomy Japanese bunching onion is a perennial herbaceous plant, usually grown as an annual for its edible leaves or white leaf bases, or both. It is unknown in the wild but probably originated in northwestern China, from an unknown progenitor. The species name, fistulosum,

Japanese bunching onion


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refers to the hollow or fistulous, tubelike leaves. The leaves are circular in cross section in contrast to the slightly flattened leaves of common onion. The bases of the leaves overlap to form a neck (pseudostem). However, unlike the common onion A. cepa, Japanese bunching onion develops only a small bulb, with a diameter just slightly larger than that of the neck. The plant flowers earlier in the spring than the common onion, hence one common name, “spring onion.” Several forms have been selected in Asia. The cultivars have been classified by different artificial systems, based not just on appearance but also on such physiological characteristics as winter dormancy, growth rate under low or high temperatures, bolting, and tillering. Lateral buds in the leaf axils usually elongate and develop into tillers (side shoots), so that a vigorous clump is formed. This tillering aspect is more pronounced in the cultivars grown primarily for their green leaves than those grown for well-developed, long, blanched pseudostems. Classification was discussed extensively by Inden and Asahira (1990). Some forms (“Kaga” and “Senju” groups) were selected for their long, edible pseudostems. These have very thick leaf blades that are often too tough to eat. The pseudostems are blanched and used like leeks (A. ampeloprasum). In fact, in Japan this form is called Japanese leek (Organ 1960). Other forms (the “Kujyo” group) have tender, green leaf blades that have excellent eating quality. One form (the “Yagura” group, sometimes known as A. fistulosum var. viviparum Makino), cultivated for its edible green leaves, produces no flowers; instead it develops clusters of vegetative bulbils at the end of modified leaves. While still attached to the maternal plant, these bulbils develop into plantlets in the late spring. The bulbils and plantlets are cut and rooted for propagation as “topsets.” Japanese bunching onion is closely related to a wild species, A. altaicum Pall., of Mongolia and Siberia. Indeed, the interspecific hybrid between these two species has high pollen and seed fertility. Another hybrid, A. ×proliferum (Moench) Schrad. (called Egyptian onion, top onion, tree onion, or catawissa onion) is a natural hybrid (i.e., produced without pollination by humans) between Japanese bunching onion and the common onion type of A. cepa (Hanelt 1990). The Egyptian onion is discussed in Culinary Herbs (Small 1997). Still another hybrid, A. wakegi Araki or wakegi onion (considered by some as part of A. ×proliferum (Hanelt 1990)), occurs naturally between Japanese bunching onion and shallot (A. cepa var. ascalonicum L. of some authors), with the former as the female parent. This hybrid develops a small bulb but does not produce fertile seeds. The wakegi onion has been cultivated as a green salad onion for centuries in China, Japan, and southeast Asia. Japanese bunching onion has a long history of cultivation. The first written record of it may have been from third century B.C. in China. However, the written character used was applied to many cultivated members of Allium. A definite description of Japanese bunching onion and its culture appeared in 100 B.C. in China. It was first mentioned in Japanese literature in A.D. 720, probably after arriving from China. The Japanese bunching onion appeared in western Europe during or at

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the end of the Middle Ages and was introduced from there to Russia. Today, some forms are widely cultivated from Siberia to tropical Asia (Inden and Asahira 1990).

Uses Forms that provide blanched pseudostems are grown in Asia. Other kinds grown only for the green portion of their leaves include a number of the familiar bunching onions in Canadian supermarkets. However, some bunching onions are forms of A. cepa, common onion. Blanched pseudostems are used in soups, stews, meat dishes, stir fries, and as a cooked vegetable. The green leaves are cooked or consumed raw in soups, salads, and as a garnish on a variety of dishes including quiches and omelettes (Halpin 1978). In Japan, Japanese bunching onion has been dehydrated for use in processed foods such as instant noodles (Inden and Asahira 1990). Example recipes

Japanese bunching onion omelette (Organ 1960) Potato soup with Japanese bunching onions (Halpin 1978)

Importance Japanese bunching onion is widely cultivated from Siberia to tropical Asia. In Japan, Korea, China, and Taiwan, it ranks among the top 10 commercial vegetables and is found in markets year-round. The leeklike basal portions are blanched and the green tops are harvested all year. Representative annual yields are 553 000 t from 24 000 ha in Japan (1985); 468 000 t from 19 000 ha in the Republic of Korea (1982); and 76 000 t from 5600 ha in Taiwan (1985) (Inden and Asahira 1990). Cultivated forms of Japanese bunching onion are commercially grown in Canada as bunching onions or scallions. In 1991, about 3100 t of domestic and 14 546 t of imported green onions (mostly A. fistulosum) were unloaded at 10 major Canadian markets (Anonymous 1992a); in 1992, 3882 t of domestic green onions were unloaded in these markets (Anonymous 1993a) Domestic statistics for “bunching onions” may include some bunching forms of A. cepa. Ontario has been reported to produce about 2500 t of bunching onions annually, while B.C. produces almost 1000 t (Anonymous 1991a, 1992h).


The most suitable soils are well-drained loams or sandy loams, high in organic matter. The pH should range between 5.7 and 7.4.

Climate

The optimum range for germination is 15–25°C; above 30°C or below 10°C germination is low. The optimal diurnal growing temperature range is 15–20°C. In Asia, types adapted to regions with cold winters exhibit deep dormancy in winter whereas forms used in warmer regions have no winter dormancy. Flowering is induced by temperatures below 13°C when seedlings have more than 11 or 12


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leaves or are more than 5–7 mm in pseudostem diameter. The period needed for vernalization (a cold period required to induce flowering) varies with different cultivars (Inden and Asahira 1990). The eating quality improves under cool temperatures as both the sugar and protein content increase. Japanese bunching onions are more tolerant of variations in water availability than most species of Allium (Tindall 1983), but they benefit from irrigation during dry periods. Propagation and cultivation

Japanese bunching onion is initially propagated by seeds sown indoors. Transplanting is carried out when the plants reach 15–20 cm in height (Tindall 1983). In commercial production in Japan, seeds are sown in early spring for winter or spring crops, and in autumn for harvest in the next summer and winter. The seeds are broadcast or drilled in nursery beds. Transplants are placed in furrows about 5 cm deep for green-top production. Some cultivars, used for green-top production, are given a 1–2 week drying treatment in summer, which promotes tillering and increases leaf production. For production of blanched pseudostems, transplants are placed in furrows, about 15 cm deep. Soil is mounded around the lower leaf bases to a height of more than 30 cm. Mounding is done gradually in three or more stages (Inden and Asahira 1990). Nonbolting or bolt-resistant cultivars are propagated by dividing the basal shoots after detaching them from the parent plants. In commercial production in Japan, these forms are divided in late May, redivided and replanted in September, and harvested the following spring. Halpin (1978) recommended that in the colder parts of North America the home gardener grow Japanese bunching onions like common onions for the first year of growth. During their second year, the plants are dug up and planted in trenches 12–15 cm deep to blanch the pseudostems. The clumps should be divided every 2–3 years and only the youngest portions retained (Organ 1960).

Harvest and storage

In commercial production mechanical harvesters are employed to lift the plants. Trimmers using high-pressure air or water remove the outer leaves. The roots are pruned and the plants are bundled for market. Plants with blanched pseudostems have the tough green upper part of the leaves removed. Plants intended for green-leaf production are also bunched, but their leaves are not removed. In Asia, yields of 20 t/ha may be obtained (Tindall 1983). The product is precooled to 0°C before storage (Inden and Asahira 1990). The onions will store for 2 weeks at 2–5°C and 3–4 weeks at –1°C (Buishand et al. 1986). For the home gardener, Japanese bunching onion can be transplanted in autumn to a greenhouse or brought into the house in pots for winter usage (Halpin 1978).

Example cultivars

Hardy White Bunching (= “He shi ko” or “Evergreen Bunching”), Ishikura, Kincho (both of the “Senju” group), Red Bunching (develops a red pseudostem), Tokyo Long White. Japanese bunching onion is occasionally listed as “Spring onion.” From the descriptions in catalogs apparently both the green-top forms

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and those grown for blanched pseudostems are offered for sale in Canada. Bettencourt and Konopka (1990) listed institutions in various countries conserving Japanese bunching onion germplasm. Facciola (1990) provided an extensive description of Japanese bunching onion cultivars available in the United States. The importance of A. fistulosum germplasm was recognized by the International Board for Plant Genetic Resources, which ranked it as the second most important species in the genus Allium (Inden and Asahira 1990).

Additional notes The odor of Japanese bunching onion is derived from volatile allyl sulphides but is not as strong as that of the more familiar common onion (A. cepa). Japanese bunching onion contains alliin, a precursor of allicin, which plays an important role in the intake of thiamin (vitamin B1) and also has a strong antimicrobial activity (Inden and Asahira 1990). Curiosities

The reported therapeutic properties of Japanese bunching onions were detailed in some ancient Chinese books; they were alleged to improve eyesight and prolong life. They were also thought to be beneficial for use in aiding digestion, perspiration, and recovery from common colds, headaches, wounds, and festering sores (Inden and Asahira 1990). The name given to “Welsh onion” has nothing to do with Wales but derives from the German Welsche, meaning “foreign” (Halpin 1978). This name was probably applied when it was first introduced to Germany in the Middle Ages.

Problems and potential Japanese bunching onion is affected by several of the same diseases and pests as other members of Allium currently grown in Canada. However, A. fistulosum is immune to some of the diseases to which common onion (A. cepa) is susceptible (Stobart 1977). Therefore, Japanese bunching onion is important in Allium breeding. Production of blanched pseudostems and green-top crops from Japanese bunching onions is important in some Asian countries, but this plant has less potential in Canada because of the seasonal nature of production. In fact, less than 20% of bunching onions used in Canada are grown domestically (Anonymous 1992a). Hydroponic culture methods have been developed in Japan to provide green-top plants year-round; there is now a specialized market for 5–7-cm long seedlings for use in soups and as garnishes in restaurants (Inden and Asahira 1990). There may be some potential for Canadian greenhouse production of Japanese bunching onion to offset imports.

Selected references Halpin 1978; Tindall 1983; Inden and Asahira 1990.

Amaranthus Amaranth Amaranthaceae Amaranth family Amaranthacées, famille de l’amarante

Genus notes Amaranthus, a genus in need of taxonomic study, is thought to comprise about 50 annual herbaceous species. These are found in many tropical and mild climates in different parts of the world (Bailey and Bailey 1976). Several domesticates, noted below, have arisen through selection and hybridization and are of economic importance as grain or vegetable plants (Simmonds 1976; Buishand et al. 1986; Schultze-Motel 1986). Amaranthus caudatus L., tassel flower, and A. cruentus L., red amaranth, which are domesticates of Andean origin, are grown for seed grain and occasionally for their edible leaves. Amaranthus dubius Mart. ex Thell., Suriname amaranth, is a domesticate that probably originated in the Caribbean. It is grown as a vegetable in the Caribbean and the southern United States. In western Europe it is apparently cultivated under glass. Amaranthus hybridus L. convar. erythrostachys (Moq.) Thell (= var. erythrostachys Moq. [Bailey and Bailey 1976]), prince’s feather, is grown for seed grain. It originated in northwestern and central Mexico. Amaranthus tricolor amaranth, discussed below, is grown both as a vegetable and as an ornamental.

Names Scientific (Latin) name: Amaranthus tricolor L. English common name: amaranth Also: Chinese spinach, vegetable amaranth French common name: amarante de Chine (f)

Description and taxonomy Amaranthus tricolor is a herbaceous plant that originated in tropical Asia. No wild form is known. This species has been selected for various characteristics, including edibility of leaves and shoots, and usefulness as an ornamental. There are notable differences among

44


forms for leaf shape and color. Three “convarieties” (groups of varieties) have been recognized to account for these variations (Schultze-Motel 1986), as follows: convariety mangostanus (L.) Thell. (= A. tricolor subsp. mangostanus (Jusl.) Aell. of some authors) convariety tricolor (= A. salisifolius Veitch of some authors) convariety tristis (L.) Thell. (= A. gangeticus L. of some authors) Plants of the first group are occasionally cultivated and grow as ruderals in India and other parts of south Asia. The red or variably colored plants of the second group are grown as ornamentals in gardens in Asia, the Philippines, Europe, and North America. Green plants of the third group are grown extensively in tropical Asia for their edible leaves and young shoots; they include most of the forms grown as vegetables. This group is known as tampala in India. In China it is called “hsien shu” (Mandarin) and “gien sok” (Cantonese) (Yamaguchi 1973). A related species, A. dubius Mart. ex Thell., is also known as tampala. It is unclear which tampala is grown in the southern United States. Amaranthus tricolor is an ancient potherb in southeast Asia. It has been used extensively in India, south and southeast Asia, China, and Japan and is now cultivated as a vegetable in West Africa and the West Indies. In Taiwan, cultivars have been selected that are red-leaved, green-leaved, and so-called tiger-leaved, a leaf red in the centre and otherwise green (Herklots 1972; Tindall 1983).

Uses The leaves and young stem tips are steamed or boiled for a few minutes until tender. They can be served with butter, put in soups, stir-fried, and added to vegetable curries. This vegetable is a substitute for spinach in lasagna dishes (Halpin 1978). In Singapore, a form that grows over 2 m tall and is said to be excellent has stems that are peeled and eaten separately from the leaves. In China the fleshy fruits produce a dye that is used as a rouge. The dye, fresh or in powdered form, is also added to jellies, pastries, and sweets (Herklots 1972). Some cultivars are widely grown as ornamental plants in gardens (Schultze-Motel 1986). Example recipes

Amaranth casserole, Canadian style (Szczawinski and Turner 1978) Amaranth salad, French style (Szczawinski and Turner 1978) Amaranth salad, German style (Szczawinski and Turner 1978) Stewed amaranth (Buishand et al. 1986) Stir-fried amaranth with pork (Halpin 1978)

Importance Little statistical information seems available on the economics of amaranth. It is most important in India (Halpin 1978) and is also

Amaranthus (amaranth)

45

grown in several parts of tropical Asia, Africa, the West Indies, Hawaii, and perhaps in the southern United States (Yamaguchi 1973; Tindall 1983; Buishand et al. 1986). In Canada, vegetable amaranth is found only occasionally in home gardens; ornamental cultivars are common.


Well-drained sandy soil rich in organic matter is desirable. The optimum pH range is 5.5–7.5 (Herklots 1972; Tindall 1983).

Climate

Amaranth is a warm-season, short-day plant that performs best when temperatures are 22–30°C. Irrigation is beneficial during dry periods (Tindall 1983).


Propagation is by seeds which, in the tropics, are commonly mixed with dry sand to provide uniform distribution. Because amaranth is a warm-season plant, it is best started indoors and then transplanted for early crops. It can be planted in succession to provide a continuous supply of leaves during the growing season. Occasional cultivation prevents competition from weeds (Tindall 1983).

Harvest and storage

In Hong Kong, the red-leaved forms are harvested when only 15–20 cm high, whereas the green-leaved forms are not picked until the plants are 40–60 cm tall (Herklots 1972). In the tropics, yields average as follows: entire plant, 20–25 t/ha; shoots only (successional harvesting) 30–60 t/ha (Tindall 1983). After harvest, roots are trimmed off and the plants are washed and tied into bundles. Crushed ice is scattered over the top layers to prevent wilting. Care is taken to avoid overpacking containers, which would damage the lower bundles (Tindall 1983). Home gardeners can harvest the entire plants when they are 15–20 cm tall. Also, a single planting will continue to yield during the entire growing season if flower buds are pinched off and the new 10–15-cm tips are harvested at 2–3-week intervals. The fresh leaves and shoots should be used immediately as storage time is limited (Halpin 1978).

Example cultivars

This plant is occasionally available as a vegetable in Canadian garden catalogs under the names “vegetable amaranth” and “Chinese spinach.” Facciola (1990) described amaranth cultivars available in the United States. The ornamental forms are more readily obtainable, often under the name tampala, or in the case of plants with blotched and colored leaves, as Joseph’s-coat. Ornamental cultivars include Early Splendor, Flaming Fountain, and Tricolor. Bettencourt and Konopka (1990) listed institutions in various countries conserving amaranth germplasm.

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Additional notes Vegetable amaranth leaves are nutritionally significant sources of carbohydrates, several vitamins and minerals, and dietary fibre. The leaves also contain oxalates, which can combine with calcium and so lower ionic calcium concentrations in the blood, leading to the disorder hypocalcemia. Oxalates can comprise 0.2–11.4% of dry matter. However, levels are significantly reduced by steaming or boiling leaves for 10 min, which does not significantly reduce nutrient levels (Sealy et al. 1990). Curiosity

The Mayans believed that grain amaranth (A. hybridus) had magical properties. The Aztecs took up the notion that amaranth grain had supernatural powers and constructed idols from the grain. They gave annual tributes of large quantities to the Aztec king, Montezuma. In plundering and destroying the Aztec civilization in the 16th century, Cortez deliberately tried to eliminate amaranth, reasoning that it was one of the foundations of Aztec civilization (Berberich 1980).

Problems and potential Studies in Nigeria (Olufolaji 1989) showed that under local conditions, and despite high consumer appeal, amaranth (A. tricolor) was not promising for commercial use because of its low yields. Vegetable amaranth is likely to remain a minor vegetable in Canada, grown occasionally in home gardens.

Selected references Halpin 1978; Tindall 1983; Sealy et al. 1990.

Apios Groundnut Leguminosae (Fabaceae) Pea family Légumineuses, famille du pois

Genus notes Apios comprises 8–10 tuberous-rooted, twining herbaceous species native to eastern North America and Asia (Bailey and Bailey 1976). The edible tubers (swollen underground storage organs derived from stem tissue) of one of these, discussed below, have been used as a food.

Names Scientific (Latin) name: Apios americana Medic. English common name: groundnut Also: potato bean, wild bean In many parts of the world the name groundnut refers to the peanut (Arachis hypogaea L.). French common name: patates en chapelet (f) Also: pénacs, Apios d’Amérique

Description and taxonomy Apios americana is a perennial wild species that has not yet been domesticated. Groundnut is native to North America, occurring on moist soils in wet thickets. It is naturally a vine or trailing plant whose slender stem climbs over other vegetation. In Canada, it grows in the southern parts of Ontario and Quebec, and in New Brunswick and Nova Scotia (Scoggan 1978–1979). Strings of underground tubers (as shown here) of this plant were harvested by native North Americans, who ate the tubers raw, boiled, or ground up. In Virginia in 1590 it was recorded that the local Indians ate groundnuts, and indeed that the tubers helped the Pilgrims survive their first winters in New England (Seabrook 1973; Erichsen-Brown 1979; Reynolds et al. 1990). Indians did not cultivate the plant, but are known to have protected and

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encouraged the growth of wild stands (Hoshikawa and Juliarni 1995). There was an effort made to cultivate groundnut in Europe during the potato famine of 1845, but this was abandoned (Hoshikawa and Juliarni 1995).

Uses Groundnut tubers can be eaten raw, or cooked either whole or grated. They can be added to soups, salads, stews, and vegetable dishes. Generally, the tubers can be cooked and used in recipes like potatoes. Peeling before cooking is not required. Cooked tubers are nutritionally of better quality than raw ones (Johnson et al. 1990). Some product development has been attempted. The tubers make excellent chips and have desirable baking qualities when blended with corn meal or wheat flour. This combination provides an excellent amino acid balance (Reynolds et al. 1990).

Importance Groundnut has attracted interest as a potential new vegetable crop. Some minor cultivation has occurred in Japan (Hoshikawa and Juliarni. Through selection, it may acquire some popularity, at least in home gardens (Duke 1987).


Groundnut is adapted to waterlogged and marginal soils and therefore has potential to flourish in areas where few other crops will grow (Duke 1987). Successful experimental plantings were conducted on silt loam with a pH of 5.7 and organic matter of 0.6% (Blackmon and Reynolds 1986). Although groundnut naturally grows in waterlogged, acidic soils, research has found that it does best in well-drained soils. The pH can range between 5 and 8 (Reynolds et al. 1990). Groundnut may present growers with a valuable opportunity to breed a rare kind of agronomic crop: a tuber crop that also (as with other legume crops) fixes nitrogen through the bacteria in its root nodules. Most tuber or root crops require the addition of large amounts of nitrogen fertilizer to the soil. Groundnut, when inoculated with Bradyrhizobium japonicum (a common soybean inoculant), showed increased yield. However, studies showed that the addition of some nitrogen maximized tuber production (Putnam et al. 1991).

Climate

Groundnut is a hardy perennial native to eastern North America, including the southern parts of eastern Canada. It needs adequate moisture during dry periods, but excessive water promotes longer rhizomes and discourages tuber formation (Reynolds et al. 1990).


Reproductive biology of groundnut was studied by Bruneau and Anderson (1988). Seed set is low; north of Connecticut seed set is virtually zero as most plants are sterile triploids (plants with three sets

Apios (groundnut)

49

of chromosomes). Normal diploid plants (with two sets of chromosomes) predominate further south, but seed set is also low, partly because of self-incompatability, and partly because of infrequent visits by leafcutter bees, which are the chief pollinating agents. Reproduction is therefore largely vegetative by the underground tubers. Direct-seeding has presented problems because some seeds are slow to germinate, requiring 10–30 days. Best results have been obtained from seedlings started in peat pellets. The young seedlings should be pinched back to the first true leaves to prevent the young plants from twining around each other. Pinching promotes better root development and allows seeds that were slow to germinate to reach transplant size about the same time (Reynolds et al. 1990). Tubers are planted intact. Groundnut has been grown experimentally on trellises of either chicken wire or bamboo canes. Determinate plants (with branches of limited growth) have been found that could be useful in developing a bush type of groundnut (Blackmon and Reynolds 1986). Harvest and storage

Tubers have traditionally been dug up by hand and washed. In colder climates, such as Canada’s, the plants may take 2–3 years to develop harvestable tubers (Duke 1987). Tests on the storability of the tubers showed that, when left to overwinter in the ground, the tubers did not exhibit noticeable compositional changes, but dry matter and sucrose content decreased as the tubers sprouted during the new season. There was little change in composition and no chilling damage in tubers stored at 4°C for 15 weeks (Picha et al. 1990).

Cultivars

No cultivars of groundnut are available. Several selections of germplasm were made during initial tests of this plant at the Louisiana State University Agriculture Center, Baton Rouge, Louisiana (Blackmon and Reynolds 1986; Reynolds et al. 1990).

Additional notes Groundnut tubers contain a crude protein content of 16.5% (dry weight), about three times that of potatoes. Feeding experiments on rats showed that cooked tubers are nutritionally superior to raw tubers (Johnson et al. 1990). Curiosities

In colonial America, Swedish immigrants ate groundnut tubers when food was scarce, and during their first winter the Pilgrims were said to be “forced to live on groundnuts” (Hedrick 1972). It appears that groundnuts were brought back to France from Canada in the 16th century and became gourmand items known as “Canada” (Seabrook 1973). Groundnuts were served at a feast, hosted by the Indian Chief Chkondum, given to Champlain when he reached the mouth of the Saint John River, N.B. (Seabrook 1973). Euell Gibbons, the noted American exponent of eating wild plants, wrote (1966) “If you want to go further afield for an exclusive

50


perfume … , try making some scent from the clusters of purplish-brown blossoms of the groundnut…. These blossoms have a rich, heady fragrance, and not every woman can live up to such a scent.” The great American botanist Asa Gray (1810–1888) offered his view that if civilization had started in America instead of in the Old World, the groundnut would have been the first edible tuber to be developed and cultivated (Medsger 1974).

Problems and potential The potential for groundnut as a commercial crop seems limited. It may find a niche in home gardens as a curiosity with usage similar to Jerusalem artichoke (Helianthus tuberosum L.). Experimental tests carried out in the long growing season of Louisiana showed a substantial yields of 24 t/ha; a single plant could produce 2.3 kg of tubers. Studies should be conducted to determine whether the tubers can be divided into sections prior to planting. Groundnut has been estimated to fix 100 kg/ha of nitrogen (Duke 1987).

Selected references Seabrook 1973; Blackmon and Reynolds 1986; Reynolds et al. 1990.

Apium Umbelliferae (Apiaceae) Carrot family Ombellifères, famille de la carotte

Genus notes Apium has about six species in Europe, temperate Asia, North America, and the circum-Antarctic zone including Australia and New Zealand (Clapham et al. 1987). The genus includes annuals, biennials, and perennials. One species, A. graveolens L., has been domesticated. The wild form of the species, var. graveolens, is a strong-smelling biennial of damp places, native to Europe, southwestern Asia, Macronesia, and North Africa (Schultze-Motel 1986). The following two cultigens, both discussed below, have been selected through domestication: var. dulce (Mill.) DC., celery var. rapaceum (Mill.) DC., celeriac (Clapham et al. 1987). Another form, var. secalinum Alef. of some authors (Orton 1983, Schultze-Motel 1986), called leaf celery, soup celery, or smallage, is a kind of wild or semiwild celery that has long been cultivated in western Europe for flavoring purposes and as a leaf garnish. It is like the wild form in that it lacks the swollen petioles of common garden celery. This form is discussed in Culinary Herbs (Small 1997), along with information on production of celery seed for the spice industry. In some parts of the world domesticated celery has escaped cultivation and has become naturalized in marshlands. This naturalization has occurred in some areas of the southern United States, but not in Canada.

Celery

Names Scientific (Latin) name: Apium graveolens L. var. dulce (Mill.) DC. English common name: celery French common name: céleri (m)

Description and taxonomy Through selection the leaf stalks (petioles) have become fleshy, more tender, and sweeter in taste than those of the related wild form. The cultigen producing edible petioles is a weak biennial but is grown as an annual. Small plants tend to produce flowers when subjected to

52


temperatures of 5–10°C for several days, but above 15°C bolting is inhibited during the first season. A rosette of compressed, upright petioles forms in the first year, producing the celery of commerce. A “bunch” of celery is simply a harvested rosette. Celery originated in the Mediterranean basin and subsequently spread east and west. The Greeks, Romans, and Chinese used it as a medicinal plant. By the 16th century in Europe, celery seems to have still been a relatively undomesticated plant, used primarily for medicine. By the 1600s Europeans were eating raw celery with oil dressings. Early celery was coarse and hollow-stemmed (Nonnecke 1989). Through most of the 19th century it was thought necessary to blanch (whiten by protecting from sunlight) the green edible portion of the stalks to rid them of unpleasant, strong flavor, which was accomplished mostly by banking up the plants with soil. By the 20th century “easy-blanching” or “self-blanching” sorts appeared. These were in turn succeeded by all-green varieties, which proved superior to the blanching kinds under favorable conditions of soil and climate.

Uses Celery petioles are consumed raw or cooked in a variety of dishes. The seed (technically half-fruits) are used as a spice or flavoring (Nonnecke 1989). The so-called “heart” of celery is the fleshy “crown stem,” marketed usually in a blanched form. Celery salt is a mixture of ground celery seed and free-running table salt. Celery oil is extracted from the seeds and used for culinary purposes. Celery adds roughage to diet, and small amounts of vitamins and minerals. Example recipes

Celery consommé (Morash 1982) Celery gratin with tomato sauce (Levy 1987) Celery stew (Morash 1982) Chanterelle feuilletés with vegetable julienne (Levy 1987) Chilled celery–lemon soup (Morash 1982) Garlic-scented zucchini with celery (Levy 1987) Scallops with celery in a vinagrette sauce (Morash 1982)

Apium (celery, celeriac)

53

Importance Domestic production of celery usually exceeds $10 000 000 annually in Canada. At least as much is imported every year (Dubé et al. 1990), almost all of it from the United States. The majority of Canada’s domestic supply is produced in Ontario and Quebec, with smaller amounts mostly in British Columbia and Manitoba.


Celery must be grown on soils that retain moisture. In the major celery areas of Canada (British Columbia, Ontario, and Quebec), well-drained muck soils are preferred. The pH can range from 6.0 to 7.5 (Nonnecke 1989).

Climate

Temperature requirements of celery are rather specific. Low temperatures cause the plant to develop slowly; temperatures above 24°C are detrimental. Juvenile plants subjected to 2–10°C for some time will bolt, forming seed stalks. Celery also requires abundant moisture because it is naturally a wetland plant. The seed germinates only in soils at or near field water-holding capacity. Germination is best when temperatures fluctuate from 15–25°C (Anonymous 1978, 1988b; Nonnecke 1989).


Celery is propagated by its tiny, slow-germinating seeds. Presoaking of seeds may be beneficial (Anonymous 1988b). Heat-treated seed or 3-year-old seed is recommended to avoid seedborne blight disease (the blight organisms become ineffective after several years within the seed). In Canada, celery is grown from transplants because of the short growing season and to control the temperature of juvenile plants to avoid bolting (Nonnecke 1989).

Harvest and storage

Celery is harvested when it is at peak quality vegetatively. Mechanical harvesting is preferred because this reduces labor demand and allows for quick transfer of the plants to suitable storage. Machines undercut and elevate the plants onto trailers. The stalks are quickly trimmed and packaged, followed immediately by vacuum or hydrocooling to a temperature of 5°C in the heart and 0–2°C on the outside. A storage relative humidity of 95% is recommended. Celery is top-iced and the shipping vehicles are refrigerated to 0°C. The butts are shipped upward to prevent water accumulation in that sensitive area (which would cause discoloration). High-quality celery held under these conditions may last 2–3 months. However, longer storage reduces quality (Nonnecke 1989).

Example cultivars

Giant Pascal, Hauser, Fordhook, Matador, Utah Green. Some recent cultivars are self-blanching or have very tender green stalks. Varieties such as Paris Golden and Stokes Golden Plume produce yellowish petioles, but these are sold on a relatively limited scale. “Winter varieties” are usually dark green forms that blanch

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more slowly than the self-blanching type and are normally raised as all-green forms. Malo and Bourque (1992) discussed recent trials of celery cultivars in Montreal. Bettencourt and Konopka (1990) listed institutions in various countries which conserve celery germplasm. Facciola (1990) provided an extensive description of celery cultivars available in the United States.

Additional notes Van Wassenhove et al. (1990) studied the aromatic compounds of both celery and celeriac as an aid to classifying cultivars. The key volatile components were found to be effective in identifying the cultivars. Curiosities

Celery is believed to be the same species as selinon, mentioned in Homer’s Odyssey, about 850 B.C. Celery seed contains an oil, apiol, but not in the same quantities as found in parsley (Petroselinum crispum). This oil has been used for several purported medicinal properties (Grieve 1978). In fact, recent studies have shown that a chemical extracted from celery, 3-n-butyl phthalide, lowered blood pressure in rats by 12–14% and lowered cholesterol by 7%. This effect has yet to be proved in humans. Over-ingestion of the oil should be avoided as it can become toxic in high doses (Anonymous 1992d).

Problems and potential Major problems exist with certain pests and diseases, as illustrated by Amor’s (1992) discussion of the 1991 celery production season in parts of Canada. Pests and diseases, including blight, were a serious problem in the Burlington/Simcoe area. Cercospora early blight and Septoria late blight were sporadic in Bradford muck soils along with Fusarium yellows. Blight was so bad that some growers left entire fields of celery unharvested. Tarnished plant bug was the most serious problem encountered. An unidentified disease, probably a mycoplasm (a unique parasitic group seemingly intermediate between bacteria and viruses), also caused losses in the Thedford – Grand Bend area. As noted in Coleman et al. (1991), about half of the celery used in Canada is imported. Although improved storage methods may allow a longer market time for domestic celery, it is unlikely that Canadian growers will be able to compete with growers in warmer climates who can supply celery during the winter months.


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Selected references Anonymous 1978, 1988b.

Celeriac

Names Scientific (Latin) names: Apium graveolens L. var. rapaceum (Mill.) DC. English common name: celeriac Also: turnip-rooted celery, turnip root celery, celery root, knob celery, celery knob French common name: celéri-rave (m)

Description and taxonomy This biennial cultigen is grown as an annual. It is unknown in the wild. The so-called root crown is the fleshy, edible part of this turniplike vegetable that tastes like celery. It grows mostly below but extending above the surface of the soil and is usually referred to as a “root” although it is a tuber (an enlarged portion of stem). The petioles of celeriac are not as swollen or long as in most garden celeries and are rather bitter in taste. The origin of celeriac is unknown (Orton 1983; Clapham et al. 1987). It was mentioned in writings from around the Mediterranean Common about 1592 and may have been derived celeriac independently from wild celery at about the same time that celery was domesticated. Celeriac was first reported in North America in 1806 but has never gained popularity anywhere (Nonnecke 1989), which limits the potential Canadian export market.

Uses The celeriac root crown is used raw or cooked in a variety of dishes, much like celery or turnip. The flavor is sweet and celery-like. Unlike celery, the hollow leaf petioles are not edible. The root crown is washed and peeled and is then boiled, baked, braised, or fried for use in vegetable dishes, soups, or stews. The raw root crown can be thinly grated and added to salads, or it can be marinated in a vinaigrette

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dressing. The fresh leaves can be used sparingly in salads or dried to add flavor (Halpin 1978). Example recipes

Celeriac and apple salad (Morash 1982) Celeriac and carrot salad (Richardson 1990) Celeriac in the Basque style (Morash 1982) Celeriac stew (Richardson 1990) Celery root purée (Levy 1987) Celery root salad with mustard dressing (Levy 1987) Cream of carrot and celeriac soup (Morash 1982) Cream of celeriac and leek soup (Morash 1982) Gratin of celeriac (Schneider 1986) Potato and celeriac cake (Morash 1982) Viennese celeriac (Organ 1960)

Importance Celeriac ranks with sauerkraut and potato as a standard winter vegetable in Germany and eastern Europe (Halpin 1978). We found no statistics describing production in North America, but the amounts would be small by comparison to Europe. Hinton (1991) noted that 28 062 t of celeriac were exported from the Netherlands in 1989, one of the large producers of this vegetable. Almost half of this went to the former West Germany. Celeriac is not a highly regarded vegetable in Canada.


Celeriac requires the same culture conditions as celery, including fertile soils that hold moisture well, such as muck soils. It tolerates a pH range of 6.0–7.6 (Nonnecke 1989).

Climate

Celeriac requires a relatively cool growing season with temperatures of 16–24°C. Juvenile plants that have produced five true leaves are sensitive to bolting if subjected to 5–10°C for a few days. For this reason the plants should be started under glass and protected until temperatures are above 16°C. Celeriac should remain well watered throughout the growing season (Nonnecke 1989).


Celeriac is propagated by its tiny seeds. They are difficult to germinate, so around 50% viability is considered acceptable. Thomas (1983) described experiments that involved presoaking seed in gibberellins with either ethephon or daminozide at high temperatures in the dark. The treatments increased the rate of germination and reduced the time of germination. Celeriac is best started indoors in Canada and transplanted, because it takes nearly 4 months before harvest.

Harvest and storage

Celeriac may be covered with soil to blanch the base of the plant. Commercially, it is harvested when the average size of the root crown


57

is about 10 cm in diameter. The plant is lifted and the tops and roots are trimmed. Celeriac stores for 3–6 months at 0°C and 95% relative humidity (Nonnecke 1989). Example cultivars

Giant Prague, Large Smooth Prague. The above cultivars require no blanching. Europeans have selected many more cultivars than are available in North America. Malo and Bourque (1992) discussed trials of the cultivar Brillant in Montreal. Bettencourt and Konopka (1990) listed Apple-shaped institutions in various countries conserving celeriac celeriac germplasm. Facciola (1990) provided an extensive description of celery cultivars available in the United States.

Additional notes Derolez and Vulsteke (1985) reported on the nitrate content of celeriac. Plants that accumulate high concentrations of nitrates can cause poisoning. Results showed that nitrate content of the root crown was strongly specific to given cultivars. Cultivars with short foliage consistently developed higher nitrates in the root crown than those with long foliage. The root crowns averaged 11% nitrates for all tested cultivars. Curiosities

The ancient Greeks and Romans believed that celeriac was a good blood purifier (Richardson 1990). In 1592, in medievial times, celeriac was recorded, as being “nearly the size of a man’s head” (Hedrick 1972), which is larger than cultivars available today. Fermented celeriac root juice is sold in health food stores (Facciola 1990).

Problems and potential Celeriac is a very minor commercial crop in Canada. It is popular in Germany and some other European countries and often remains so among transplanted Europeans. It has not become a popular food in Canada, and its prospects seem limited.

Selected references Halpin 1978; Nonnecke 1989.

Arctium Great burdock Compositae (Asteraceae) Sunflower family Composées, famille de la marguerite

Genus notes Arctium has about five biennial species. These are native to Europe and Asia, with some naturalized in North America (Clapham et al. 1987).

Names Scientific (Latin) name: Arctium lappa L. English common name: great burdock Also: gobo, edible burdock, cuckold, harlock French common name: grande bardane (f) Also: bardane majeure, artichaut, rhubarbe sauvage, rapace, graquias, toques

Description and taxonomy Arctium lappa is a biennial herbaceous plant grown as an annual. The cultivated form is little changed from the wild plants, although Schultze-Motel (1986) separated it as var. edule (Sieb.) Mansfeld. Great burdock is widely used as a vegetable in Japan, where it is known as “gobo” or “takinogawa.” Under exceptional conditions the roots can grow to 1 m in length and become the size of a baseball bat. The wild plant is native to Eurasia (Bailey and Bailey 1976) and has been introduced along roadsides, thickets, fields, and waste places in North America. Scoggan (1978–1979) reported that it has been found in Canada in British Columbia and from Manitoba east to Nova Scotia (excluding Prince Edward Island). A hybrid with another introduced relative, A. minus (Hill) Bernh., has been reported from Quebec.

Uses The roots of great burdock have an oysterlike flavor similar to salsify (Tragopogon porrifolius, also discussed in this book). Before cooking, the outer layer is scraped off, down to the white fiber underneath. The roots are usually boiled in two changes of water to improve the vegetable’s color and flavor. When cooked the roots are crunchier than carrots and slightly stringy, but not unpleasantly so. Burdock can be used in oriental-style

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Les légumes du Canada

stir-fries or added to vegetable dishes, stews, soups, or meat dishes (Halpin 1978). Example recipes j j j j j j j j

Brown rice baked with burdock and dried mushrooms (Schneider 1986) Burdock salad (Buishand et al. 1986) Burdock with egg (Buishand et al. 1986) Candied burdock stems (Szczawinski and Turner 1978) Chicken with burdock and mushrooms (Schneider 1986) Deep-fried gobo (Szczawinski and Turner 1978) Gobo in vinegar sauce (Szczawinski and Turner 1978) Sliced beef with gobo (Szczawinski and Turner 1978)

Importance Great burdock is grown commercially in Japan (Halpin 1978). A major Japanese firm markets “hamburgers” made with chopped burdock root cooked in soy and sesame oil, with bacon and seaweed. In Canada, great burdock is imported into the country in small quantities and is occasionally found in specialty stores in Toronto (Anonymous 1989).


Great burdock grows best in fertile soil. Loose soil structure is essential for long, straight roots. It is recommended that the soil be prepared by digging a trench at least 45 cm deep. After adding well-rotted compost, the trench is refilled and the seeds are planted about 0.5 cm deep and 10 cm apart (Halpin 1978).

Climate

Great burdock is grown extensively in Japan. It should perform well across the southern parts of Canada where it has successfully naturalized. This plant needs limited water, and overwatering inhibits root growth.


Great burdock is propagated by seeds, which are sown outdoors once the soil is warm. The seeds are planted 0.5 cm deep and 15–20 cm apart. Burdock needs little care until harvest. However, the leaves can become quite large, and space should be left between rows. Great burdock can also be grown in greenhouses, with seeds planted directly in tubs or bottomless boxes that are filled with soil (Halpin 1978).

Harvest and storage

Great burdock should be harvested before the roots mature fully. Mature roots are flavorful but can be tough. The major agricultural problem with great burdock is harvesting the long roots. However, if the seedbed is prepared as described above, it should not be difficult to dig up the roots. Halpin (1978) presented techniques to facilitate gathering of great burdock roots. One method is to dig a trench beside the plant, exposing one side of the root. The roots can then be pulled at an angle. Some Japanese farmers build boxes on top of the ground and fill these with soil. At harvest time, they dismantle the boxes, which saves the work of digging deep into soil. This technique also serves to keep burdock from spreading. The tops are removed before storage. Great burdock will store for several weeks at 0°C with high humidity (Buishand et al. 1986).

Arctium (grande bardane)

Example cultivar

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Takinogawa Long. Importation of seeds of great burdock into Canada has been forbidden (unpublished memorandum, 9 Nov. 1990, by the Seed Division of the Plant Health Directorate, Food Production and Inspection Branch, Agriculture Canada, concerning importation of weed seeds and of seeds of species not listed in schedule 1 of the Regulations under the Seeds Act). The extent to which exceptions would be made for importation of great burdock seeds intended for use as a vegetable has not been explored.


j

j

j

j

The name “bur” is said to come from the French “bourre,” derived from the Latin “burra,” a lock of wool. This reference is to bits of wool often found attached to the burs in sheep pastures (Grieve 1978). The plant owes its spread to the hooked prickles on the fruits, the “burs” that adhere to almost anything. Shakespeare had Pandarus say in Troilus and Cressida “They are Burs, I can tell you, they’ll stick where they are thrown.” Great burdock roots were regarded as an important herbal medicine in the Middle Ages, for example, finding use as a blood purifier and as a treatment for skin diseases such as eczema and boils (Grieve 1978). Great burdock roots wrapped in wet heavy paper and roasted over coals are reputed to taste suprisingly like meat (Halpin 1978).

Problems and potential Great burdock is essentially unknown as a vegetable in Canada with the exception of groups of Asian origin, especially the Japanese. Although it is well adapted to the Canadian climate, its potential seems limited. However, seeds can be obtained by Canadian home gardeners, and a limited market may be possible.

Selected reference Halpin 1978.

Asparagus Asparagus Liliaceae Lily family Liliacées, famille du lis

Genus notes Estimates of the number of species of Asparagus range from 100 to 300. The genus includes perennial herbs, woody vines, and shrubs, all native to the Old World (Bailey and Bailey 1976). Only one of these species (A. officinalis) is widely used as a vegetable. However, young, spineless spears of the spiny A. acutifolius L. are locally collected and eaten from the wild from Spain to Greece. Several species, especially those referred to as “asparagus ferns,” are grown as ornamentals.

Names Scientific (Latin) name: Asparagus officinalis L. English common name: asparagus Also: common asparagus, garden asparagus French common name: asperge (f)

Description and taxonomy Asparagus is a perennial herbaceous plant that has both wild and domesticated forms (Clapham et al. 1987), as noted below. Subspecies officinalis (A. officinalis var. altilis L. of some authors) includes wild, undomesticated asparagus native along the seacoasts of Europe, Asia, and North Africa, as well as domesticated plants that have been selected. Subspecies prostratus (Dumort.) Corb. is a native wild form found along grassy seacoasts of the British Isles and coastal Europe from northern Germany to northern Spain. Use of asparagus likely started in the eastern Mediterranean region over 2000 years ago, when Roman writers gave instructions for growing it. The Romans preferred asparagus grown from seeds collected from wild forms. The domesticated form has escaped from cultivation and can be found as a naturalized plant across southern Canada in all provinces,

62


except perhaps Saskatchewan (Scoggan 1978–1979). The American naturalist Euell Gibbons (1962) is noted for his book, Stalking the Wild Asparagus, advocating the culinary use of naturalized asparagus and other wild plants. Garden asparagus is one of the few crop plants that have male and female flowers on different plants. In older literature it was thought that the sex-determining mechanism is the same as for humans, with females arising by a combination of two X sex chromosomes, and males by the union of an X and a Y chromosome. However, it is now believed that a single gene controls gender (Machon et al. 1995). Plants of the two sexes arise in about equal numbers. Female plants produce larger and better shoots than the males and are preferred. However, males are rarely discarded, as their identification (when raised from seed) requires growing the plants for 2 years, by which time considerable investment has been made in establishing the plants. Current breeding in asparagus tends to be for the production of all-male hybrids. Asparagus is a long-lived perennial, which once planted may be productive in a garden for 40 years, although 15 years is usually considered to be the economically useful period. The rootstock or crown sends up aerial shoots each spring, which are succulent when young. Harvested at lengths of 12–23 cm, they provide the edible “spears” of asparagus. The shoots that are not harvested produce plants ranging up to 3 m in height, with fernlike, finely dissected foliage. Each fall the plants die back to the ground.

Uses Asparagus spears are used raw or cooked in various dishes. Their raw tender tips can be added to salads. The spears are boiled, baked, or fried for use as a vegetable and are added to soups, stews, pasta dishes, and casseroles (Yamaguchi 1983; Nonnecke 1989). Asparagus is also frozen, canned, and occasionally (primarily in Europe) dried. Example recipes

Asparagus and Roquefort canapés (Levy 1987) Asparagus and carrots with Madeira (Levy 1987) Asparagus soup (Morash 1982) Asparagus vinaigrette mimosa (Owen 1978) Asparagus with beurre blanc (Levy 1987) Asperges à la Colin (Buishand et al. 1986) Cream of asparagus soup with tarragon (Owen 1978) Escargot and asparagus in puff pastry (Richardson 1990) Fettucine with morels and asparagus (Levy 1987) Oven asparagus puff (Morash 1982)

Importance Representative statistics for Canadian production of asparagus are given in the Introduction. Asparagus is grown in several provinces, but

Asparagus (asparagus)

63

about 70% of production occurs in Ontario. The key processing province is British Columbia, which uses Washington State spears for most of its production. Asparagus is a specialty crop in the Atlantic Provinces, with small amounts delivered to roadside markets and restaurants. More asparagus is imported than grown in Canada (Dubé et al. 1990). In typical years, domestic production is about 25% of total asparagus consumed or processed in Canada. Of the imported asparagus, most comes from the United States, with some from Mexico (Coleman et al. 1991). Most imported asparagus is for the fresh market, but some is processed (frozen, canned, and so on).


Because asparagus is a long-lived perennial crop that can last for decades, careful soil preparation is essential. Deep, loose, well-drained sandy loams with at least 2% organic matter are recommended. Heavy soils should be avoided as they often cause malformed spears. Asparagus tolerates both alkaline and acidic soils, within the pH range 6.0–7.5. The phosphorus:potassium balance must be maintained by providing adequate organic matter (Anonymous 1988a; Nonnecke 1989).

Climate

Asparagus responds well to Canadian climates and can be grown successfully to at least 55°N latitude. The optimum temperature range for germination is 16–30°C. In Canada, the seedlings are grown in a nursery for 1 year and then planted in 15-cm deep furrows where they are allowed to grow for two more seasons. Asparagus grows fast. Asparagus shoots can develop from 10 cm (the minimum harvestable length) to 25 cm (the maximum) in 5.3 days at a daily mean temperature of 11°C to 1.9 days at a daily mean of 25°C. Asparagus is frost-sensitive, so areas with late or early frost should be avoided to ensure maximum yield. The plant becomes dormant in late autumn when frosts occur, which is essential for spear production. The above-ground portions of the plant are killed by frost, and the rhizome (underground stem) overwinters. Asparagus is quite responsive to rainfall or irrigation during its active growing phase but does not tolerate waterlogged soils (Production Committee 1986; Nonnecke 1989).


Asparagus can be propagated either by seeds or by plants that are 1–3 years old. Seeds are sown either in nursery rows or preferably in a permanent bed in a deep furrow. As the young plants grow and become established, the furrow is gradually filled in. Farmers normally plant one-year-old crowns in their production fields. The first spears can be harvested 3 years from seed or 2 years from transplanting. The beds will improve in productivity up to the seventh year, and a bed may remain productive for 15 years or more, especially if kept disease-free (Nonnecke 1989).

Harvest and storage

Fresh spears are hand-harvested. In harvesting, a riding machine has proven no more economical than simply walking. Spears are cut with a knife or snapped off. Harvesting is repeated whenever the spears

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reach the marketable length of 12–23 cm. Care is necessary to prevent damage to younger, emerging shoots. Asparagus can be blanched by hilling soil over the rows and cutting the spears deep within the ridge as the tips appear. The resulting white asparagus is preferred in Europe. A small amount of blanched asparagus is grown in Ontario. Templates for grading asparagus are available from the Food Research and Development Centre, Research Branch, Agriculture and Agri-Food Canada, Saint-Hyacinthe, Quebec (Doyon and Savoie 1992). In southern Canada, the harvest season lasts 4–6 weeks. In the Prairies, harvest time is reduced to 1–2 weeks to allow sufficient time for foliage growth to restore rhizomes for the next year’s harvest (Nonnecke 1989). Although canners prefer that spears be snapped off at ground level, the home gardener may choose to harvest the spears when they reach a height of 15–20 cm above the ground surface, using a knife held at an angle about 5 cm below the ground surface to cut through the spears. Asparagus spears are stored at 2.2°C and high relative humidity for up to 2 weeks. The following types of damage can occur (Nonnecke 1989): Chilling injury: Injury occurs if spears are held at temperatures between –3 and 0°C. The spears become dull and limp. Bending and elongation: If spears lie horizontally for more than a day they bend upwards. Elongation occurs if the spears are left standing in water with temperatures above 4.4°C. Feathering: The bracts “feather” (separate) if they are left uncut too long, especially with an excessively high temperature or low relative humidity. Low O2 injury: This injury occurs if asparagus is packed in improperly ventilated plastic film at too high a temperature. Example cultivars

Jersey Giant hybrid, N.J. Centennial, Viking series, Mary Washington. The Viking series was developed in Canada from Mary Washington progeny. An improvement program is underway at the University of Guelph to breed new cultivars, including all-male hybrids that can outyield more traditional cultivars. Ellison (1986) extensively discussed the potential and problems of asparagus breeding. Cutcliffe and Stevenson (1990) described cultivar trials in Prince Edward Island. Facciola (1990) provided an extensive description of asparagus cultivars available in the United States. Bettencourt and Konopka (1990) listed institutions in various countries conserving asparagus germplasm.

Asparagus (asparagus)

65

Additional notes Asparagus is a diuretic (urine production stimulant), and a curious problem for some individuals is a characteristic odor in the urine. Curiosities

The name asparagus in derived from the Greek aspharagos, meaning sprout (Richardson 1990). The ancient Greeks believed that asparagus grew from a ram’s horn sunk into the ground. In colonial America, asparagus was called “sparrowgrass” (Richardson 1990). As early as the 1800s, rock salt was recommended as a yield-enhancing soil amendment for asparagus. Asparagus can tolerate high concentrations of salt because it originated in maritime regions of the Mediterranean. Salt was also an effective weed killer when applied at 9 kg/93 m2 (20 lb/1000 sq ft). When herbicides replaced salt for weed control in the 1950s, asparagus crown rot, due to Fusarium fungi, became a serious problem. Studies have shown that the addition of chlorine to asparagus beds enhances the resistance of asparagus to Fusarium fungi (Cole 1992). Asparagus has been used medicinally, for example, as a laxative and diuretic and in the treatment of dropsy (Grieve 1978). Like other plants suggestive of phallic appearance when they sprout from the soil, asparagus has been widely regarded by different cultures as a powerful aphrodisiac.

Problems and potential The 1990 annual report of the Ontario Asparagus Growers’ Marketing Board highlighted several economic realities of the Canadian asparagus industry. Consumption was down; the Canadian dollar was up; and the cost of American asparagus had been reduced. With the advent of the Free Trade agreement, competition from the United States is significant. In the 1940s and 1950s, about 90% of the Ontario crop was used for processing. Now, less than 30% is sold to processors. At the Asparagus Research Program at the University of Guelph, several promising varieties have been selected and are being examined. Varieties from around the world have been compared. Work has also been done on commercializing clones that could

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provide plants yielding two to three times the production of some current varieties. Storage research has been carried out at Vineland Research Station (Agriculture and Agri-Food Canada). The Production Committee (1986) noted that more research is needed on insect and disease problems. Desjardins et al. (1991) stated that there was considerable potential for increasing Quebec production of asparagus. They outlined a method, for growing plants from seed in greenhouses for the purpose of transplanting to the field, that they felt could make growing asparagus in Quebec more economical.

Selected references Anonymous 1986a, 1988a; Cutcliffe and Stevenson 1990; Jaques 1990.

Atriplex Garden orach Chenopodiaceae Goosefoot family Chénopodiacées, famille du chou gras

Genus notes Atriplex consists of more than 100 annual or perennial, herbaceous or shrubby species, found around the world (Bailey and Bailey 1976). Many of the species are adapted to saline habitats, and in western Canada (and elsewhere in the world) these are promising for development as forage crops, adapted to salty conditions that preclude growth of virtually any other economic plants. Several species are grown as ornamentals and one, discussed below, is cultivated as a vegetable.

Names Scientific (Latin) name: Atriplex hortensis L. English common name: garden orach Also: orach, French spinach, mountain spinach French common name: arroche (f) Also: arroche épinard

Description and taxonomy Atriplex hortensis is an annual growing to 2 m tall. Its infra-specific classification requires study. The treatment found in Schultze-Motel (1986) is followed here: subsp. hortensis contains the cultigen and possibly also some wild forms subsp. nitens (Schkuhr) Pons (A. nitens Schkuhr, of some authors), a wild form considered more primitive than subsp. hortensis, is found in middle to southern Europe and west to central Asia and Siberia; it might best be reduced to a constituent of subsp. hortensis (Schultze-Motel 1986) subsp. desertorum (Iljin) Aellen is a wild group native to the southwestern and central parts of the Commonwealth of Independent States (Schultze-Motel 1986) The extent to which subsp. hortensis includes wild forms is unclear. Apparently wild plants in the Orient and parts of central Asia have been assigned to this group (Schultze-Motel 1986). Three domesticated color variants have been recognized in this subspecies:

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whitish, green, and red (= var. atrosanguinea of some authors (Bailey and Bailey 1976; Scoggan 1978–1979). The whitish variant is considered sweeter and more tender than the reddish form (Halpin 1978). The red variant is used as an attractive red-leaved ornamental, and for its edible young shoots and leaves. In Canada, this subspecies (usually the whitish form) is found in wastelands, dumps, and roadsides from British Columbia to Quebec, and in the District of Mackenzie (Scoggan 1978–1979; Bassett et al. 1983). The red variant has been found in Saskatchewan (Scoggan 1978–1979) and was observed by the senior author in central British Columbia. It is uncertain whether the green variant has escaped in Canada. Garden orach was familar to the ancient Greeks and Romans who employed it to sooth sore throats, ease indigestion, and cure jaundice. It became popular during medieval times in European countries as a culinary as well as medicinal wild herb. Italians added it to pasta and the French and English used it in soups, stews, and as a steamed side dish. During the 17th and 18th centuries, garden orach was brought to the New World where it became a common vegetable. In the 19th century it was replaced by spinach, but its consumption continues in Europe, and to a lesser extent elsewhere (Halpin 1978).

Uses Young leaves and shoots of garden orach are eaten like spinach. It has a mild flavor with a less bitter taste than spinach. The vegetable is boiled and buttered, creamed, added to quiches, rolled up in crêpes, tossed in cold salads, and added to soups (Organ 1960; Halpin 1978). In addition to its culinary use, garden orach is cultivated as a garden ornamental. Example recipes

Braised orache (Buishand et al. 1986) Sardinian orach (Organ 1960) Springtime salad with orache (Buishand et al. 1986)

Importance Garden orach is commercially grown in central and southern Europe (Buishand et al. 1986). This vegetable is cultivated in the midwestern states in America, where it does not bolt as readily as spinach. Garden orach is considered hardier than New Zealand spinach, Tetragonia tetragoniodes (also discussed in this book) (Halpin 1978). No information seems available on amounts or value of garden orach in Canada, where it is occasionally grown in home gardens.

Atriplex (garden orach)

69


Garden orach thrives on well-drained fertile soils, preferably in light shade. High organic matter is beneficial. It is tolerant of alkaline soils with a pH above 7.0 (Halpin 1978).

Climate

Garden orach is a cool-season plant that is sown as soon as the soil can be worked in the spring. The emergent seedlings can tolerate temperatures of –3°C without apparent injury. It is not as susceptible to bolting as spinach (Spinacia oleracea L.), which forms a flower stalk during late spring and summer (Yamaguchi 1983). Garden orach performs better when lightly shaded. Although it tolerates dry soils, it produces shoots that are more tender when watered during dry periods (Halpin 1978).


Propagation is by seeds, sown 5–12 mm deep. Germination is much reduced if seeds are planted as deep as 25 mm. Light cultivation is beneficial for controlling weeds when the plants are young (Yamaguchi 1983). Garden orach does not transplant well and is best direct-seeded (Organ 1960). Successive plantings every 2 weeks until early summer ensures a supply of tender young plants for harvest (Halpin 1978).

Harvest and storage

Commercial garden orach is harvested when the plants are 10–15 cm in height. Home gardeners can thin plants at this stage and use the removed plants as a vegetable. When the plants are older, the tender young leaves (6–8 cm long) are harvested; the coarse, older leaves are left to sustain growth (Yamaguchi 1983). Leaves of flowering plants are also considered less desirable. The flower buds should be pinched off as they appear, to encourage branching (Halpin 1978).

Example cultivars

Both ornamental and culinary cultivars have been bred. As a vegetable, this plant is occasionally sold in Canadian garden catalogs simply as orach or French spinach.

Additional notes Curiosity

In Russia, a blue dye is extracted from the seeds (Bassett et al. 1983).

Problems and potential Garden orach is a very minor vegetable in Canada and seems likely to remain so. It has potential as a replacement crop for spinach.


Barbarea Upland cress Cruciferae (Brassicaceae) Mustard family Crucifères, famille de la moutarde

Genus notes Barbarea has about 12 annual or biennial species native to the northern hemisphere (Bailey and Bailey 1976). Barbarea vulgaris R. Br., known as common winter cress, rocket, and yellow rocket, is native to Europe and has been naturalized in North America. Although this plant has been collected from the wild for use as a salad plant, it is not employed commercially (Halpin 1978). Barbarea verna, occasionally grown for its edible leaves, is discussed below.

Names Scientific (Latin) name: Barbarea verna (Mill.) Aschers. Frequent scientific synonym: B. praecox (Sm.) R. Br. English common name: upland cress Also: winter cress, early winter cress, Belle Isle cress, American cress, land cress, scurvy grass [see Crambe maritima for note regarding the name scurvy grass] French common name: cresson de terre (m) Also: cresson de jardin [the latter is ambiguous, because it is also applied to Lepidium sativum, garden cress], herbe de Sainte Barbe [a name also applied to B. vulgaris R. Br., a species mistakenly, we believe, identified by Boivin (1992) as the upland cress encountered in commerce in Quebec].

Description and taxonomy Upland cress is a biennial herbaceous plant native to the western Mediterranean region and Macronesia. It grows along roadsides and streams, and on waste and cultivated ground. The cultivated selections are indistinguishable from the wild forms. Wild plants have been introduced to much of Europe, North America, South Africa, Japan, and New Zealand (Clapham et al. 1987). In Canada, wild upland cress has become established in

Barbarea (upland cress)

71

southwestern British Columbia. It has also been found on the French islands of Saint Pierre and Miquelon (Scoggan 1978–1979). Little information seems available on early cultivation of upland cress. In Sweden, during the 18th century, upland cress was collected for spring and autumn salads and boiled like kale (Brassica oleracea var. viridis) (Organ 1960).

Uses The immature leaves of upland cress are eaten fresh in salads and cooked as a vegetable. They may also be used as a seasoning or garnish. The young flower buds can be added as a flavoring to salads and vegetable dishes (Halpin 1978; Owen 1978). The young seedlings are tasty sprouts. Example recipes

Cress soup (Organ 1960) Upland cress quiche (Halpin 1978)

Importance Upland cress is a minor crop, grown in Europe (especially in France) and in North America (Buishand et al. 1986). No information seems available on amounts or value of upland cress produced commercially.


Sanders (1994) recommended fertile, well-drained sandy loam or clay loam soils and a pH range of 5.8 to 6.5. He also recommended maintaining organic matter by turning under cover crops.

Climate

This cool-season biennial can withstand some autumn frost. It is sown as early as the soil can be worked. The plants require additional moisture during dry periods (Splittstoesser 1990). Upland cress grows best at temperatures less than 20°C, and semi-shade is advisable during hot weather (Halpin 1978).


Upland cress is propagated by seeds, which are planted in soil in shaded, moist areas and lightly covered. The seedlings are thinned to about 10 cm apart. Successive plantings will provide a regular harvest throughout the growing season (Organ 1960).

Harvest and storage

The leaves of upland cress are hand-harvested as needed. They are best consumed fresh, and the younger leaves have the best flavor. Harvesting generally ends once a flower stalk forms, because subsequently the leaves become too bitter.

Cultivars

Cultivars are unavailable in Canada. This plant is occasionally sold in Canadian garden catalogs as upland cress or winter cress.

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Additional notes It may be noted that “winter cress (Barbarea spp.)” is classed as a weed under federal Canadian legislation (Anonymous 1986c), so that in theory importing seeds into Canada could present problems.

Problems and potential Because of competition from similar vegetables, notably watercress, Nasturtium officinale (also dealt with in this book), upland cress is likely to remain an obscure specialty crop in Canada, occasionally grown in home gardens.

Selected references Halpin 1978; Splittstoesser 1990; Small 1997.

Basella Malabar spinach Basellaceae Basella family Basellacées, famille de la baselle

Genus notes Basella has five species of twining, herbaceous vines native to tropical areas of Africa and Asia (Bailey and Bailey 1976). One species, discussed here, is grown as a potherb.

Names Scientific (Latin) name: Basella alba L. English common name: Malabar spinach Also: Indian spinach, Ceylon spinach, basella, vine spinach French common name: baselle (f) Also: épinard de Malabar

Description and taxonomy This short-lived, twining perennial vine produces fleshy, edible leaves. In tropical areas it spreads aggressively, commonly exceeding 5 m. Three forms are available in the tropics for cultivation, each distinguishable by its leaf shape and color. They include forms with dark-green, oval leaves (available in Canada) red, oval-rounded leaves and red stems (= B. rubra L. of some authors [Tindall 1983]) dark-green, heart-shaped leaves (= B. cordifolia Lam. of some authors [Tindall 1983]) The ancestors of the cultivated forms are unknown, and it is not clear if genuinely wild forms are present in nature, or if all wild plants represent escaped cultivated plants. Malabar spinach is now distributed throughout the tropics, both in cultivation and as an escape. Malabar spinach was introduced to Europe in 1688. By the 19th century it was grown in French gardens, using superior varieties that had been introduced from the Orient (Hedrick 1972).

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Uses Malabar spinach leaves and young shoots are cut, cooked, and eaten like spinach, or mixed into soups and meat stews (Herklots 1972; Tindall 1983). Example recipe

Basella casserole (Buishand et al. 1986)

Importance Malabar spinach is an important vegetable in eastern Asia and India (Herklots 1972). It is rarely cultivated in Canada, where it is known only as an occasional crop in home gardens.


Malabar spinach grows well in a wide range of soils but performs best in moist fertile soils high in organic matter. Supplementary application of fertilizer high in nitrogen may be beneficial (Tindall 1983).

Climate

This tropical plant is adapted to high temperatures. Irrigation is required during dry periods. Normally, it flowers only during short days and would not flower during the Canadian summer, which is desirable as flowering results in bitter leaves. However, stress from lack of water induces early flowering and reduces leaf production, so adequate moisture is necessary. Light shade promotes the growth of larger leaves than develop under full sunlight.


Propagation is by seed, stem cuttings, or crowns placed in hills (Herklots 1972; Tindall 1983). In Canada, Malabar spinach is started from seeds indoors and transplanted outdoors after danger of frost is past. Plants are trained on poles, trellises, or fences and may reach more than 1 m in length.

Harvest and storage

Malabar spinach is hand-harvested. Pruning the lateral shoots (they can also be eaten) prolongs the vegetative growth phase. Harvested leaves should be refrigerated as quickly as possible. In the tropics, single plants may yield up to 1.5 kg of fresh leaves and young shoots over a period of 180 days (Tindall 1983).

Example cultivar

Basella Malabar Green Stem. Bettencourt and Konopka (1990) listed world institutions with germplasm resources of Malabar spinach.


The dark red juice of Malabar spinach was used as a dye and ink in ancient China (Tindall 1983). Malabar spinach is one of many tropical plants having the C4-cycle photosynthetic pathway (Tindall 1983), which allows for increased growth if temperature and light intensity are sufficiently high.

Basella (malabar spinach)

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The famous student of primates Dian Fossey (1983) noted that Basella alba is one of the foods utilized by gorillas.

Problems and potential Malabar spinach will likely remain a crop of home gardens, used mainly by Canadians whose cultural background has made them familiar with the vegetable, and by those curious enough to try it. It has essentially no commercial prospects in Canada because it can be cultivated more economically in climates warmer than those found here.

Selected references Herklots 1972; Tindall 1983.

Benincasa Wax gourd Cucurbitaceae Gourd family Cucurbitacées, famille de la courge

Genus notes Benincasa contains only one species, the cultivated B. hispida (Bailey and Bailey 1976).

Names Scientific (Latin) name: Benincasa hispida (Thunb.) Cogn. English common name: wax gourd Also: fuzzy gourd, fuzzy melon, Chinese winter melon, Chinese watermelon, Chinese preserving melon, white gourd, white pumpkin, ash gourd, zit-kwa, tunka, mogwa French common name: courge à la cire (f) Also: melon velu, mogwa

Description and taxonomy Wax gourd is a pumpkinlike, tendril-bearing, annual herbaceous vine. The existence of wild populations is unconfirmed. The cultivated forms may have originated in eastern Asia (Randhawa et al. 1983). Wax gourd is mentioned in Chinese writings of the 5th and 6th centuries A.D. The plant is now grown throughout the Old World tropics; recently, it has been introduced in warmer parts of the New World. A recent study of cultivars of wax gourd has resulted in a classification based on comparative analysis of vegetative, floral, and fruit characters (Walters and Decker-Walters 1989). Four categories of wax gourd are described. Unridged winter-melon group. The seeds of this group are unridged, and the fruits are large. This group and the next two are common to China and to other parts of western Asia. Ridged winter-melon group. In this group the seeds have ridged margins, and the fruits are elongate.

Benincasa (wax gourd)

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Fuzzy-gourd group. The seeds of these plants are ridged, and the fruits are covered with soft white hairs. Wax-gourd group. The seeds of this type are ridged, and the fruits of many cultivars are covered with a white waxy bloom. This group predominates in India.

Uses The uses of wax gourd are varied. Immature fruits are picked and used as a vegetable. The flesh may be added to soups or stews. The mature fruits of the unridged winter-melon group are used by the Chinese as soup pots. The immmature fruits of the fuzzy-gourd group can be sliced and eaten raw, boiled, or stir-fried. The flesh of the softer-rinded wax-gourd fruits are used in curries or are sugar-coated and eaten as a sweet in India, Malaysia, and Cuba (Walters and Decker-Walters 1989). In southern and eastern Asia, ripe fruits are used in making preserves and sweet pickles. Example recipes

Sliced wax gourd (Herklots 1972) Stuffed wax gourd (Herklots 1972) Tung kwa chung (Herklots 1972) Wax gourd stew (Buishand et al. 1986)

Importance In northern India, up to 20 t/ha of wax gourd are obtained, with individual fruit weighing 12–40 kg each (Tindall 1983). In Canada, wax gourd is currently grown only in home gardens and may be of most interest to Canadians of Asian ethnic origin who have acquired a taste for the plant.


Soils must be warm, and production is best on substrates with high organic matter content. Optimum soil pH is 5.0–5.4.

Climate

Wax gourd is a tropical plant that requires warm temperatures to grow, preferably 24–27°C. It is susceptible to cold temperatures but can tolerate drought. In Canada, plants are transplanted outdoors only after all danger of frost is past. Wax gourd requires abundant water to ensure good growth and needs supplementary irrigation during dry periods (Yamaguchi 1983).


Wax gourd is cultivated much like pumpkin and squash. Propagation is by seeds, started indoors 6–8 weeks before transplanting outside. This vine is preferably provided with a trellis or fence 2–3 m high to grow on, although in some parts of the world the plants are allowed to trail over the ground. Hand-pollination may be required to obtain good fruit set (Herklots 1972; Tindall 1983).

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Harvest and storage

Fruits are hand-picked when young and tender (about 15 cm long). Wax gourd will keep for more than 6 months if stored at 13–15°C and 70–75% relative humidity (Yamaguchi 1983).

Example cultivars

Fuzzy-gourd group: Fuzzy Gourd. Unridged winter-melon group: Chinese Winter Melon. Bettencourt and Konopka (1990) listed institutions in various countries conserving wax gourd germplasm.

Additional notes Wax gourd vines grow rapidly in warm weather. Vines have been measured as averaging an extension of almost 1 cm/h over 4 days (Herklots 1972). Curiosities

Wax gourd was purported for relief of thirst and as a diuretic (stimulant of urine flow). A fresh slice rubbed on the skin was said to relieve prickly heat instantly but was not a cure (Herklots 1972). In China, wax gourd is grown on the banks of village ponds. A bamboo framework is erected over the water, and the plants are encouraged to grow upon the frame so that the fruits hang over the water. This method ensures an abundance of water for the plants and saves land space (Herklots 1972).

Problems and potential Wax gourd is likely to remain a curiosity of home gardens, because it requires a long, warm growing season untypical of Canada. It should be grown on trellises for better fruit development, which makes it labor intensive.

Selected references Herklots 1972; Tindall 1983; Walters and Decker-Walters 1989.

Beta Chenopodiaceae Goosefoot family Chénopodiacées, famille du chou gras

Genus notes There are about six species of Beta. These annual or biennial herbs are native to Europe and Asia (Clapham et al. 1987). One species, B. vulgaris, has been domesticated. An elaborate formalized system of nomenclature of cultivar groups can be found in Schultze-Motel (1986). A simpler scheme is to recognize only the following two subspecies of cultivated plants (Bailey and Bailey 1976; Clapham et al. 1987): subsp. vulgaris whose cultivated forms include beet, sugar beet, mangel, and fodder beet, all of which have enlarged underground storage organs subsp. cicla (L.) Koch, Swiss chard, grown for its edible leaves and petioles, lacks the enlarged root of subsp. vulgaris The ancestry of the two cultivated types has proven difficult to establish. The evolutionary affinities of both cultigens to the wild taxa, as well as to primitive cultivated races, are unclear (de Bock 1986; Ford-Lloyd and Hawkes 1986; IBPGR 1989; Letschert and Frese 1989). The wild forms may be annual or biennial (rarely perennial). The most common wild form is subsp. maritima (L.) Thell., known as sea beet, which is native to seashores of Eurasia and north Africa. The taxonomy of other wild forms was discussed by Schultze-Motel (1986). Doney (1989) discussed the population dynamics and evaluation of germplasm of subsp. maritima. Flowering drains the edible parts of the plant of food reserves and makes tissues woody and unpalatable. The cultivars of B. vulgaris have undergone strong selection to grow as biennials, so that premature flowering (bolting) does not occur in the first year of growth. If permitted to grow for a second year, the plants flower and produce seeds. The so-called “seed” of B. vulgaris is usually an aggregate structure, developed when several flowers coalesce and an irregular, dry, woody mass of one-seeded fruits called a seed ball is formed. Generally two to six seeds are found in a seed ball. So-called “monogerm” varieties produce single-seeded fruits that do not coalesce into seed balls, making it unnecessary to devote effort to thinning the clumps of seedlings that develop from seed balls.

Swiss chard

Names Scientific (Latin) name: Beta vulgaris L. subsp. cicla (L.) Koch

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English common name: Swiss chard Also: chard, silver beet, seakale beet, leaf beet French common name: bette à carde (f) Also: bette, bette poirée, bette à côtes, betterave poirée, carde, carde poirée, blète, blette The name chard is also sometimes given to blanched shoots of globe artichoke (Cynara scolymus) and to young flowering shoots of salsify (Tragopogon porrifolius). The name seakale beet sometimes is used for Swiss chard, but this usage may produce confusion with the true sea kale (Crambe maritima). All these other species are discussed in this book. The name leaf beet reflects the edible character of the leaves of Swiss chard (Beta vulgaris subsp. cicla), but the more familiar beet (Beta vulgaris subsp. vulgaris), discussed later, also has some cultivars with edible leaves.

Description and taxonomy This cultigen is similar to beet except that the root is not enlarged. Two forms have been domesticated: those with swollen midribs are called Swiss chard or chard, those without a swollen midrib and abundant leaf material are called leaf beets or spinach beets (Ford-Lloyd and Williams 1975; Ford-Lloyd and Hawkes 1986). This herbaceous biennial is grown as an annual for its edible leaves and petioles (Clapham et al. 1987). It is believed that wild beet leaves were harvested as a potherb several thousand years ago, in the Mediterranean lands where Beta occurs indigenously and was domesticated. The east Mediterranenan area is considered as the centre of diversity of both cultivated and wild Beta, with secondary centres in Asia and north Africa. Swiss chard is a very old vegetable. The ancient Greeks recognized red, white, and “black” (intense deep green) forms, and the Romans were also well acquainted with this vegetable. Swiss chard was introduced to North America by Europeans in 1806. In North America it is grown mainly in home gardens (Nonnecke 1989).

Uses Although less popular than its cousin, beetroot, Swiss chard is a popular vegetable in home gardens, its petioles serving the role of asparagus, a much more seasonal vegetable. Swiss chard leaf stalks (petioles) are cooked like celery and taste best after steaming. They can also be used in stir-fries. The leaf blades (often with the leaf

Beta (beet, Swiss chard)

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stalks attached) are cooked like spinach, using only the water left on the leaves after washing. In fact, a combination of spinach and Swiss chard has a pleasant flavor (Nonnecke 1989). It may be noted that, as is the case in many genera of the goosefoot family, the leaves of Beta contain appreciable amounts of calcium oxalate, which can be toxic when consumed to excess. Example recipes

Chinese-style Swiss chard soup (Morash 1982) Colorful vegetable blanquette (Levy 1987) Grandmother’s red Swiss chard (Buishand et al. 1986) Individual Swiss chard custards (Morash 1982) Jugoslavian chard pancakes (Richardson 1990) Molded Swiss chard, ham, and leek custard (Schneider 1986) Piquant Swiss chard (Buishand et al. 1986) Swiss chard and pork gayettes (Morash 1982) Swiss chard ribs with sea trout (Morash 1982) Swiss chard torta (Morash 1982) Swiss chard with lemon, oil, and pine nuts (Schneider 1986)

Importance Swiss chard is a minor crop in North America. California, Florida, New Jersey, and Texas are the major regions of production (Nonnecke 1989). Canadian production, intended for local markets, is limited to small areas. For example, less than 2 ha were planted in Nova Scotia in 1991 (Amor 1992).


Swiss chard responds well to deep loamy soils high in organic matter. The pH should be 6.5–7.5.

Climate

Swiss chard grows in all gardening areas of Canada. Unlike beets, it does not respond to high temperatures by bolting. In fact, chard must be subjected to extended periods of chilling to induce flowering. Germination begins when soil temperature reaches at least 5°C. Because of its large leaf area, supplementary moisture may be required during dry periods (Nonnecke 1989).


Propagation is by seed, generally direct-seeded, although some northern producers start Swiss chard in sheltered areas such as cold frames or hot beds and transplant the seedlings after all danger of frost is past, to gain an early start on the season (Nonnecke 1989).

Harvest and storage

Swiss chard is hand-harvested by removing the outermost leaves without damaging the inner growing tip. Regular picking of the outer leaves ensures a continuous harvest. Chard must be rapidly cooled to remove field heat and reduce respiration. It can be stored for 10 days at 0°C and 90–95% relative humidity before shipping.

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Example cultivars


Whitish petioles and midribs include Fordhook Giant, Silverado, Silver Giant, White King. Red petioles and midribs include Rhubarb Chard. Seed production of Swiss chard occurs in the Pacific Northwest region of the United States (Jarmin and Thornton 1985d). Aspects of conservation of Beta germplasm were discussed in IBPGR (1989). Facciola (1990) provided an extensive description of cultivars available in the United States.


Despite its name, Swiss chard has no special association with Switzerland (Richardson 1990).

Problems and potential Swiss chard is a minor crop in Canada, generally produced and supplied locally. This vegetable seems unlikely to increase in importance because of its short shelf life and limited popularity. There may be potential for production of seeds in cooler parts of Canada.

Selected references de Bock 1986; Whitney and Duffus 1986; IBPGR 1989.

Beet

Names Scientific (Latin) name: Beta vulgaris L. subsp. vulgaris English common name: beet Also: beetroot, sugar beet French common name: betterave (f) Also: betterave potagère [name to avoid: bette (Boivin 1992); sugar beet: betterave sucrière]

Description and taxonomy Beet can be grown as a biennial or perennial, although in Canada it is treated as an annual. The swollen, fleshy underground part of many


Growth rings of beet

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root crops is actually a combination of shoot (stem) and root, although commonly referred to simply as root. The upper portion of the structure originates from the hypocotyl (the part of the seedling shoot between the primary leaves and the root); the lower portion is derived from the root. In globe-type garden beets, most of the storage organ is hypocotyl; in longer storage organs, the bottom portion is often derived from the root. In sugar beet, most of the storage organ is root. The hypocotyl part of the beet storage organ lacks branch roots, whereas the tap root portion possesses two opposite rows of secondary roots. In the following, the common practice of referring to beets as “roots” will be followed, although as explained here this description is not quite accurate. The beet has an enlarged root, consisting of a series of alternating bands of conducting and storage tissue (referred to as “zoning;” these zones are actually growth rings). Beetroots vary in shape from globular to tapered. The pigmentation is temperature controlled, and high temperatures result in poor coloration (Nonnecke 1989). Beet roots vary in color from red-purple, red, and pink through yellow and white. Their red coloration is related to the glucoside betacyanin dissolved in the central vacuole of the cells; in most vascular plants, red color is caused by anthocyanin pigments. In beets, a combination of violet betacyanins and yellow betaxanthines give beets their red color. By altering the ratio of the two pigments, beet colour can range from violet through red and orange to yellow. Fodder beets (also called mangel-wurzel, mangel, and mangold) are used as animal feed. The coarse-grained storage organs are large and frequently weigh more than 1 kg; they often rise some distance out of the ground. Colors vary as in the garden beet, but white is most commonly encountered. Beets are a relatively recent crop. Whereas Swiss chard was domesticated by classical Greek times, beets were first reliably reported in the 12th century A.D. Through time the root was selected from a long tapered form to a rounded shape. Fodder beets were developed by the 1700s and sugar beets were first recognized in 1747 by a German chemist. By 1801, the first sugar refinery for sugar beets was operating in Europe, and in 1897 in California (de Bock 1986; Nonnecke 1989). Mangold beet

Uses Garden beets are a popular salad vegetable, and young beet roots are excellent for pickling. The basis of the popular Russian soup, borsch, is a beet purée. Beets can be purchased bunched with or without tops. Both the root and tops can be steamed or boiled. The tops are used like spinach. Most roots are processed, either whole, sliced, or cubed. The juice is added as a colorant in many products (Nonnecke 1989). Beet roots are used in soups, stews, and casseroles and are added cold to salads.

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Example recipes

Baby beets with beet greens (Morash 1982) Baked beets with lemon cream (Levy 1987) Beet chutney (Morash 1982) Beets with cream sauce (Morash 1982) Beets with orange and dill (Ornish 1990) Borsch (Tudge 1980) Chilled beet and cucumber soup (Morash 1982) Endive and beet salad with champagne vinaigrette (Levy 1987) Red flannel hash (Morash 1982)

Importance The major production regions for beets in Canada are Ontario and Quebec; Ontario produces the highest yields per hectare (Nonnecke 1989). Domestic beet production satisfies almost all of Canada’s domestic fresh and processed beet demand (Coleman et al. 1991). Sugar beets are one of the most important industrial crops of the temperate and subtropical zones (de Bock 1986). Because sugar cane cannot be grown in temperate climates, sugar beet is the Sugar beet major domestic source of sugar in many northern countries; indeed beet sugar accounts for almost half of the world’s production of refined sucrose. As with cane sugar, raw sugar from beet is brown and is made white by refining. Impurities not crystallized in the refining process produce molasses, which can be used in manufacturing fusel oil, alcohol, rum, and vinegar. The pulp remaining from the extraction process, and the tops of the plants, are useful as stock feed, and as fertilizer. Canadian production of sugar beets sometimes exceeds 1 million t annually, grown over 25 000 ha, with a value of more than $30 million dollars, mostly in Alberta and Manitoba. Several sugar factories use sugar beets in Alberta, Manitoba, Ontario, and Quebec. Modern cultivars have up to 20% sucrose content. Trials of fodder beets were conducted in Manitoba (Clark et al. 1981) using European cultivars. Fodder beets yield a greater crop per hectare than sugar beets but have less dry matter. The roots can be fed to cattle either whole or chipped. Also, they may be useful for ethanol production, yielding 2½ times more than corn and 50% more than sugar beets.


Well-drained loamy soil with well-rotted manure is best for beets. The soil pH should be between 6.8 and 7.8. Good fertility is essential for beet production.


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Climate

Beets require cool temperatures for germination and development of deep red color. Sustained temperatures of 4.5–10°C for 15 days can trigger bolting, which prevents the root from reaching a marketable size. Irrigation is essential during dry periods (Nonnecke 1989).


Propagation is by seed, which is precisionseeded by commercial growers. Spacing is determined by the eventual use of the roots. Fresh bunching beets are grown to about 5 cm in diameter. Over-ground Processing beets are either used as small whole beets, beet resting on or as larger sliced or diced pieces. For successive earth surface harvests of beets a 10-day interval is common between sowings. Cultivation or use of herbicides is often necessary to prevent competition from weeds (Nonnecke 1989).

Harvest and storage

Beets produced for bunching are generally hand-pulled and tied together in the field. They may be sold with or without the tops. Processing beets are mechanically pulled and topped, then washed and sorted. Beets are cooled to 0°C with high relative humidity. They should be mature as less shrinkage will occur during storage. Beets can be piled in perforated bags that permit good air circulation or placed in pallets (Nonnecke 1989). Uncooked beets will keep for a few months at 3–5°C (Buishand et al. 1986).

Example cultivars

Red round cultivars: Big Red, Detroit Dark Red, Feuerkugel Hybrid, Little Ball, Ruby Queen. Red cylindrical cultivar: Tendersweet Cylindra. Yellow round cultivar: Burpee’s Golden Delight. Cultivars providing tasty leaves: Green Top Bunching, Lutz Green Leaf. Recent trials of beet cultivars grown in Montreal were described by Malo and Bourque (1992). Aspects of conservation of Beta germplasm were discussed (IBPGR 1989). Facciola (1990) provided an extensive description of classes of beet and of cultivars available in the United States. Bosemark (1989) described the prospects for sugar beet breeding and the use of genetic resources. Pear-shaped beet Production of seed of table beets is undertaken in the Pacific Northwest of the United States, where more than 250 ha are planted annually (Jarmin and Thornton 1985d). Because the plants are wind-pollinated, growing uncontaminated seed requires isolation.


A pleasant wine has been made from beet roots and a good domestic ale has been brewed from the mangold. A considerable

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amount of alcohol can be obtained by distillation, especially from sugar beet cultivars (Grieve 1978). Various medicinal properties were attributed to beets. The sugar beet was said to be “good for headache and swimmings therein and all affections of the brain.” The juice of red beets was said to be beneficial for jaundice and toothaches (Grieve 1978). Fodder beets weighing over 50 kg have been grown. Crop diversification is a major concern in agriculture today (note “Preface”). Perhaps the most famous case of crop diversification in history is that of sugar beets. Napoleon instituted measures that promoted the beet sugar industry in France, following disruption of the supply of cane sugar from the West Indies, caused by the British naval blockade. The process of extracting sugar from beet roots was developed by Andreas Margraff in 1747. Through selection by breeding, the sugar content of beets increased from just 2% in the 19th century to over 20% today (Simpson and Conner-Ogorzaly 1986).

Edible leaf beet

Problems and potential The domestic market for processed and fresh beets is currently near the saturation point in Canada (Coleman et al. 1991). There is little potential for expansion of commercial vegetable beet production. There may be potential for seed production in cooler parts of Canada.

Selected references de Bock 1986; Whitney and Duffus 1986; IBPGR 1989.

Brassica Cruciferae (Brassicaceae) Mustard family Crucifères, famille de la moutarde

Genus notes The Old World genus Brassica includes about 40 species of mostly annual herbs, with some perennial herbs and small shrubs (Bailey and Bailey 1976). Brassica is an extremely complex group, in which several species have evolved by hybridization. Separating the intergrading variants that different authorities have recognized is difficult, even for specialists; no comprehensive account that is easy to understand is available. Readers may take solace in the fact that this genus may well be the most puzzling of domesticated plants and requires much more study. Both vernacular and scientific nomenclature of many of the domesticated plants are confusing. For example, in North America broccoli refers to an annual green-sprouting form known in Britain and Italy as “calabrese.” In Britain, the term broccoli is sometimes used in a seasonal context to distinguish different groups of cauliflower. A guide to interpreting common names is provided below. Several systems of formal Latin nomenclature have been developed. The work of L.H. Bailey on classification of cultivated Brassica (Bailey 1922, 1930, 1940), although dated, remains one of the most authoritative treatments available. This work has been incorporated into a recent synoptic treatment (Schultze-Motel 1986), which is followed here because it is the most complete modern work available. More recent studies dealing with certain species are noted in the following discussions. Some modern taxonomists have suggested cultivar groupings that may more closely reflect natural relationships than traditional classifications (Oost and Toxopeus 1986; Gray 1989). Recent DNA studies have suggested changes to the classification of groups within the genus Brassica (Song et al. 1988, 1990; Warwick and Black 1991). Much more work needs to be done. The table beginning on page 91 shows the nomenclature of important species of interest to Canada (Banks 1980; Prakash and Hinata 1980; Tsunoda et al. 1980; Yamaguchi 1983; Schultze-Motel 1986; Terrell et al. 1986; Gray 1989). Several additional species of Brassica are of economic importance worldwide. Several species are highly polymorphic and display great variation. These have been selected for different features including leaves, stems, flowers, and swollen stem bases (Bailey and Bailey 1976; Oost et al. 1989). Numerous parallel forms have been selected, especially in B. juncea, B. oleracea, and B. rapa. These three species differentiated historically along similar lines, as shown in the table on page 90 (adapted from Nishi 1980 and Prakash and Hinata 1980). Not all these morphological types are available in Canada.

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Nomenclature of the major vegetables in the genus Brassica Species B. alboglabra L. [= B. oleracea var./subsp. alboglabra (L.H. Bailey) Musil of some authors Snogerup et al. (1990), Warwick and Black (1991)] B. campestris L. [included under B. rapa] B. dubiosa Bailey1 B. juncea (L.) Czern. [Several of the variants have been given formal taxonomic names; see discussion in footnote in the next table] B. napus L. [= B. napus var. napobrassica (L.) Reichenb. (Terrell et al. 1986)] B. oleracea L.

Var./subsp.

pai-tsai leaf mustard, mustard greens, Chinese mustard greens, chieh tsai, gai (kay) choy (choi), takana subsp. rapifera Metzg.

rutabaga, swede

var. botrytis L. [Botrytis group2]

cauliflower, heading broccoli, perennial broccoli, late white-sprouting broccoli, bouquet broccoli broccoflower cabbage (green and red) Portuguese cabbage

var. botrytis L. × var. italica Plenck var. capitata L. [Capitata group2] var. costata DC. [Tronchuda group2] var. gemmifera DC. [Gemmifera group2] var. gongylodes L. [Gongylodes group2] var. italica Plenck [Italica group2]

var. medullosa Thell. [Acephala group2] var. sabauda L. [Capitata group2] var. sabellica L. (Acephala group 2] var. viridis L. [= var. acephala DC. of some authors Schultze-Motel 1986)], [Acephala group2] B. perviridis (Bailey) Bailey [= B. rapa subsp. perviridis Bailey of some authors, Perviridis groups2; sometimes as part of B. campestris]

Common names Chinese Kale, Chinese broccoli, gai (kai) lon, guy lan, gai lohn, chieh lan, kai lon

Brussels sprout(s) kohlrabi, turnip kale broccoli (sprouting), calabrese, green-sprouting broccolis, true-heading broccolis, white-sprouting broccoli (early), purple-sprouting broccoli marrow-stem kale savoy cabbage Scotch kale3, curled kitchen kale kale, borecole, collards

spinach mustard, tendergreen, mustard spinach, po leng chieh, komatsuna

Brassica (cole crops)

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Species B. purpuraria (Bailey) Bailey1 B. rapa L. [= B. campestris L. of many North American authors (Terrell et al. 1986)]

B. ruvo Bailey [often included under B. rapa; Ruvo group4] 1

B. septiceps (Bailey) Bailey

Var./subsp.

Common names tse tai tsai, tze tsai hua

subsp. chinensis (L.) Hanelt [= B. campestris subsp. chinensis (L.) Makino; B. oleracea var. chinensis (L.) Prain (Terrell et al. 1986), Chinensis group2; includes B. parachinensis Bailey, sometimes known as choy sum] subsp. narinosa (Bailey) Hanelt [= B. campestris var. narinosa (Bailey) Olssen; B. rapa var. narinosa (Bailey) Kitam. (Terrell et al. 1986) subsp. nipposinica (Bailey) Hanelt [= B. campestris L. subsp. nipposinica (Bailey) Olsson (Terrell et al. 1986)] subsp. pekinensis (Lour.) Hanelt [= B. campestris subsp. pekinensis (Lour.) Olssen; B. pekinensis (Lour.) Rupr. (Terrell et al. 1986); Pekinesis group2] subsp. rapa [= B. camprestris L. var. rapifera Metzger) Sinsk. (Terrell et al. 1986); Rapifera group2]

Chinese mustard, celery mustard, bok (pak) choy (choi), pei-tsai, chongee

Chinese savoy, ta ko tsai, taatsai

shui tsai, mizuna, mibuna, kyona

Chinese cabbage, celery cabbage, bow sum, bok choi, pai-tsai, won bok, wong bok, pao, hsin pei tsai, napa, nappa, hakusai, siew choy turnip, rapini

ruvo kale, Italian turnip, broccoli, broccoli raab, spring raab Italian kale, seven-top turnip

1Included

for completeness, although these groupings are of doubtful merit. according to Bailey and Bailey (1976) and Huxley et al. (1992). 3Kales and collards are interpreted differently by different authorities. Some authors include “collards” under var. sabellica. 4B. ruvo is discussed under B. oleracea var. italica (broccoli) because of its similar agronomy and usage. 2Groups

Some species also have important uses other than as vegetables (Schultze-Motel 1986). These include mustard plants, oilseed plants, and forage. Mustard plants

B. carinata A. Braun, Abyssinian mustard, Ethiopian mustard. B. juncea (L.) Czern., Indian mustard, brown mustard (see following table, footnote 1) B. nigra (L.) Koch., black mustard.

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Similar morphological variation in Brassica oleracea, B. rapa, B. juncea Variation Basic leafy

B. oleracea var. viridis; kale

B. rapa (= B. campestris L.) —

Bush

var. viridis; thousand-headed borecole var. viridis; Portuguese kale var. capitata; cabbage var. sabauda; savoy cabbage

subsp. nipposinica; mizuna, mibuna, kyona (J)

B. juncea1 leaf mustard; hakarashi-na (J2) shelifong, serifong, hsueh li hung (C)

subsp. pekinensis; santosai (J,C)

katsuo-na (J,C)

subsp. narinosa; chirimen hakusai (J,C) subsp. rapa; turnip

chirinmen, takana (J,C)

Loose Head Heading Savoy Turnip

—

Kohlrabi

var. gongylodes; kohlrabi

—

Elongated stem

var. medullosa Thell.; marrow-stem kale var. botrytis; cauliflower

—

Stalking

tsaishin (J,C)

turnip mustard; ken-chetsai (C) pickling mustard; tsa-tsai (C) ta-sin-t’sai (T) tashin-chetsai (T) kigarashi (J,C)

1Common

names only are given for B. juncea. Scientific names are given by Herklots (1972), Anonymous 1985, and others. However, authorities disagree so extensively in their classification systems and interpretations of names for B. juncea, that scientific nomenclature is omitted, following Schultze-Motel (1986). 2(J) = Japan, (C) = China, (T) = Taiwan.

Oilseed plants

B. napus L. subsp. napus [var. napus of most North American authors; subsp. oleifera Metzg. of some authors; and still other nomenclature by others]. In Canada, the vernacular “Canola” is applied to this oilseed variety as well as to oilseed B. rapa, below. B. rapa L. subsp. dichotoma (Roxb.) Hanelt [B. campestris var. dichotoma (Roxb) Olssen Kitam. of most North American authors]. This annual oilseed plant is known as toria or Indian rape. subsp. oleifera (DC.) Metzg. [B. campestris subsp. rapifera (Metzg.) Sinsk. of most North American authors]. This important oilseed plant is called rape or Canola in Canada. subsp. trilocularis (Roxb.) Hanelt [B. campestris subsp. trilocularis (Roxb.) Olssen of most North American authors]. This annual oilseed plant is known as yellow sarson or Indian colza.

Forage plants

B. napus L. subsp. napus [var. pabularia (DC.) Rchb. of some authors (Schultze-Motel 1986)], Siberian kale, Hanover salad B. oleracea L. var. medullosa Thell., marrow-stem kale

Guide to plants called broccoli, cauliflower, cabbage, kale, and turnip Brassica vegetables are collectively known as “cole” crops. The word “cole” was proposed in 1901 by the American horticulturalist


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L.H. Bailey for cabbage and its allies. The term is counterpart for chou in French (broadly, “cabbage”) and Kohl in German (all from the Celto-Germanic-Greek caul, meaning “stem”). Common names can be confusing and for this reason we list in the following all the Brassica varieties that have been given the common names of broccoli and cauliflower, cabbage, kale, and turnip, and show the corresponding scientific names. Common names Chinese kale, Chinese broccoli cauliflower, heading broccoli, perennial broccoli, white-sprouting broccoli (late), bouquet broccoli broccoli (sprouting), calabrese, green-sprouting broccoli, true-heading broccoli, white-sprouting broccoli (early), purple-sprouting broccoli Italian turnip broccoli, ruvo kale, spring raab, broccoli raab

Scientific names B. alboglabra B. oleracea var. botrytis

Cabbage

cabbage (green and red) Savoy cabbage Chinese cabbage, pak-choi Chinese cabbage, celery cabbage pai-tsai Chinese savoy, ta ko tsai

B. B. B. B. B.

oleracea var. capitata oleracea var. sabauda rapa subsp. chinensis rapa subsp. pekinensis rapa subsp. narinosa

Kale

Chinese kale, Chinese broccoli Portuguese kale marrow-stem kale Scotch kale, curled kitchen kale turnip kale, kohlrabi kale, borecole, collard Siberian kale, Hanover salad ruvo kale, Italian turnip broccoli

B. B. B. B. B. B. B. B.

alboglabra oleracea var. costata oleracea var. medullosa oleracea var. sabellica oleracea var. gongylodes oleracea var. viridis napus subsp. napus ruvo

Turnip

turnip mustard, ken-chetsai turnip kale, kohlrabi turnip, rapini Italian turnip broccoli, ruvo kale seven-top turnip, Italian kale

B. B. B. B. B.

juncea oleracea var. gongylodes rapa subsp. rapa ruvo septiceps

Broccoli and cauliflower

B. oleracea var. italica

B. ruvo

Guide to the oriental brassicas Crops representing several different Brassica species are loosely termed Oriental or Asian brassicas. Many of these are so much alike in origin, history, and cultivation that they are often confused. Different spellings for a particular vegetable exist because various authors writing in English gave a Romanized account of the original oriental names (Herklots 1972). For example, Chinese kale is variously called (in papers written in English) “gai lon,” “kai lon,” “guy lan,” “gai lohn,” or “chieh lan.”

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Oriental Brassicas after Banks (1980), Yamaguchi (1983), and Schultze-Motel (1986)). Latin name B. alboglabra1

English name Chinese kale, Chinese broccoli

Oriental name gai (kai) lon, guy lan, gai lohn, chieh lan (M),2 wai lon (C) mustard greens, Chinese green mustard chieh tsai (M), gai (kai) choy (choi) (C), takana (J) tender green, spinach mustard po leng chieh (C)

B. juncea B. perviridis B. rapa3 B. subsp. chinensis Chinese mustard, celery mustard B. subsp. narinosa Chinese savoy, broad-beaked mustard B. subsp. nipposinica B. subsp. pekinensis Chinese cabbage, celery cabbage (includes the “nappa” and “michihli” types)

pei tsai (M), bok (pak) choy (choi) (C), chongee (J) ta ko tsai (C) shui tsai (C), mizuna, mibuna, kyona (J) siew choy, bow sum, bok choi (C), pai-tsai, won bok, wong bok, pao, hsin pei tsai (M), napa, nappa, hakusai (J)

1This

plant is discussed under B. oleracea var. viridis, kale. names: M = Mandarin Chinese, C = Cantonese Chinese; J = Japanese. 3These four crops are discussed under B. rapa subsp. chinensis, Chinese mustard. See page 126 for a more detailed account of “Oriental cabbage" of B. rapa. 2Oriental

Oriental Brassicas

Chinese cabbage

Mustard greens

Spinach mustard

Chinese savoy

Chinese mustard

Mizuna


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Mustard greens

Names Scientific (Latin) name: Brassica juncea (L.) Czern. English common name: mustard greens Also: Chinese mustard, Indian mustard French common name: moutarde chinoise (f) Also: moutarde de l’Inde, moutarde brune, moutarde de Sarepta, moutarde de Chine.

Description and taxonomy Brassica juncea is an annual herbaceous plant, selected for various features including seeds for oil or flavoring, forage, and as a vegetable. The seeds are a major component of prepared mustard. Indeed, as noted below, the major production area of mustard is North America, including the Prairie Provinces of Canada. Until the 1950s Brassica nigra (L.) Koch. was the major crop grown for pungent “mustard,” but in a decade B. juncea displaced the former because of mechanized harvesting (B. nigra had to be hand-harvested). The related Sinapis alba L. is commonly grown for “mild” mustards. Some cultivars are important as a major oil crop. For more information on the use of B. juncea and S. alba as mustard plants see Small (1997). Other selections of B. juncea are used as green manure and animal fodder (Simmonds 1976). Some of the cultivars selected as leaf and stem vegetables are discussed here. Authorities disagree so extensively in their classification systems and interpretations of names for B. juncea that scientific nomenclature is omitted, following Schultze-Motel (1986). Scientific names are given by Herklots (1972), Anonymous (1985), and others. Herklots (1972) also provided illustrations of Oriental vegetable forms. The following discussion is restricted to mustard greens, which are grown in Canada. Mustard greens are similar to B. perviridis, spinach mustard or tendergreen, which is treated separately. They are often discussed together in agronomic texts because of their similarity (Halpin 1978; Tindall 1983). Brassica nigra and B. rapa L. are parent species of B. juncea, which originated in the central Asian Himalayas, with secondary centres in India, China, and the Caucasus, although strong evidence suggests independent hybridization of B. nigra with local forms in those areas. Yellow-seeded forms arose in the Orient (Simmonds

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1976). It is uncertain whether there are any genuine wild forms or whether plants outside cultivation are ruderal, having escaped from cultivation. In Canada, B. juncea has escaped and become a weed. It is found in all provinces and the Northwest Territories, in cultivated ground and waste places (Scoggan 1978–1979). It was likely originally used in Canada for its pungent “mustard” seeds. Mustard was among the earliest of spices, recorded in about 3000 B.C. in Sanskrit writings of ancient India. The present-day mustard greens are thought to have been originally selected on the Indian subcontinent (Simmonds 1976).

Uses Mustard greens can be cooked like spinach by briefly steaming the leaves and stems. In China they are added to soups and salads or stir-fried. Some cultivars have swollen stem bases that are boiled and then peeled and sliced (Harrington 1978; Tindall 1983). Example recipes

Salad of mustard greens and avocado with sweet-hot dressing (Schneider 1986) Sausages and mustard greens with spaghetti (Schneider 1986) Scallops and shrimp with mustard greens sauce (Schneider 1986)

Importance Mustard greens are important as a vegetable crop in parts of Asia, eastern Europe, and Africa. They are also used in parts of the United States. Average yields in parts of Asia are 20 t/ha (Tindall 1983). No information seems available on production of mustard greens for vegetables in Canada. Mustard greens are sold in the retail market in Toronto (Anonymous 1989).


Mustard greens will grow on a variety of soils, but a sandy loam soil high in organic matter is best. Soil pH should be 5.5–6.5 (Halpin 1978; Tindall 1983).

Climate

Mustard greens are best grown in the cool season. The plant is photoperiod-sensitive to long days, which results in bolting. The optimum growing temperatures are 15–18°C. High temperatures cause the leaves to become peppery in taste, so hot weather should be avoided. Mustard greens are also suitable for growth in winter greenhouses at temperatures of about 12–14°C. Irrigation is beneficial during dry periods because regular watering prevents the buildup of pungent flavors in the leaves (Halpin 1978; Tindall 1983; Splittstoesser 1990).


Propagation is by seed. Seeds of mustard greens can be planted outdoors 3–4 weeks before the last frost date or 6–8 weeks before the first autumn frosts. This vegetable is also suitable for greenhouse or hydroponic production during the winter. Added nitrogen may be needed for leaf production. Progressive plantings are recommended


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for a continuous crop. The leaves become unpalatable once the plant begins to bolt (Halpin 1978; Tindall 1983). Jarmin and Thornton (1985c) described seed production of the mustards. Harvest and storage

Example cultivars

Mustard greens are ready to harvest when leaves are 10–12 cm long. If leaves are allowed to become too mature, they lose their tenderness and taste pungent. Mustard greens can be harvested as entire plants, or the lower leaves can be harvested regularly. If the plants are allowed to bolt, the mature seeds can be collected and ground for use as mustard (Halpin 1978). Mustard greens: Florida Broadleaf, Giant Curled, Green Wave. There are both traditional Oriental selections as well as many selections made in the United States. Common and cultivar names are often difficult to interpret with mustards. “Green in Snow” and “Swollen mustards” are probably selections of mustard greens; “Serifong” or “Hsueh-Li-Hung” is likely a bushy type of mustard greens with deeply dissected leaves. Bettencourt and Konopka (1990) listed institutions in various countries that conserve B. juncea germplasm. Genetic diversity and conservation requirements for B. juncea are described in Anonymous (1981). Facciola (1990) provided an extensive description of mustard green cultivars available in the United States.


Mustard condiment became very popular in 14th century France. It is reported that the court of Louis IV consumed over 100 gallons (450 L) of it during a feast. Mustard “plasters” are often applied in home medicine as a means of relieving chest congestion and for applying heat to aching muscles. The heat produced can burn skin and cause severe blisters, so that the poultice should not be left on for much more than 20 min.

Problems and potential Mustard greens are susceptible to various disease and pest organisms. Crop rotation of 3–4 years is recommended, i.e., growing the crop in the same location only once in 3 or 4 years (Tindall 1983). The mustard greens crop is minor in Canada, and its potential seems limited to market gardens for local consumption. This crop will likely remain of interest to Canadians with ethnic familiarity with the vegetable.

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Selected references Halpin 1978; Harrington 1978; Tindall 1983.

Rutabaga

Names Scientific (Latin) name: Brassica napus L. subsp. rapifera Metzg. English common name: rutabaga Also: swede, Swedish turnip, winter turnip French common names: chou-navet (m), rutabaga (m) Also: chou-navet blanc; names to avoid: rabiole, navet blanc, chou de Siam, navet (Boivin 1992)

Description and taxonomy Brassica napus is an annual or biennial herbaceous plant. It can overwinter and flower the following spring if planted in autumn in regions with little frost. It includes two economically important subspecies (Schultze-Motel 1986). Subspecies napus. This subspecies includes the rapeseed of commerce (var. oleifera Metzg. of some authors is applied to the oil form and subsp. napus to the fodder form). Canola, the Canadian-developed low-toxic variety of rapeseed used for edible oil and as animal feed, is a name applied to forms of both B. napus and B. rapa (B. campestris L. of many North American authors). This subspecies also includes forage rape fed to sheep in northern Europe and New Zealand, and the vegetable crop known as Siberian kale or Hanover salad (subsp. pabularia (DC.) Janchen of authors), which is discussed elsewhere under B. oleracea var. viridis, the kale-collards. Subspecies rapifera. Also known as B. napobrassica (L.) Mill. and B. napus var. napobrassica (L.) Schübl. (Schultze-Motel 1986), this subspecies includes the rutabaga or swede, a biennial that is discussed here. Of the yellow- and white-fleshed forms of rutabaga, the yellow form predominates. It is uncertain whether there are truly wild forms of B. napus (Simmonds 1976). Old World in origin, it probably originated several times as a cross between cultivated and wild B. oleracea and wild B. rapa (Simmonds 1976). In Europe, subsp. napus is found as a ruderal on arable land and banks of streams and ditches (Clapham et al. 1987). In Canada, it occasionally survives after cultivation and may


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spread to waste ground. It has been found in all provinces and the Northwest Territories (Scoggan 1978–1979). First recorded in Europe in 1620, swedes were introduced to Britain in 1775–1780, probably from Sweden, and were known as turnip-rooted cabbage. In 1806, the so-called Swedish turnip or “rutabbage,” likely the yellow-fleshed form, was being cultivated in American gardens (Simmonds 1976; Nonnecke 1989). Rutabaga is called a “root,” although it is substantially stem tissue. It closely resembles the turnip (B. rapa subsp. rapa), discussed separately. However, rutabagas have a short stem or neck, unlike the turnip.

elongated neck

no neck

Turnip

Rutabaga or Swede

Uses As a vegetable, rutabaga is used raw, in salads, or cooked in soups or as a dinner dish. Rutabaga flesh is solid and retains its color after cooking (Nonnecke 1989). Example recipes

Baked honeyed rutabaga disks (Morash 1982) Indian pakoras (Tudge 1980) Lynn Wilson’s rutabaga pudding (Morash 1982) Rutabaga pie (Morash 1982) Rutabaga roulade (Morash 1982)

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Importance Rutabagas represent less that 2% of the value of the fresh vegetable market in Canada. Domestic production supplies almost all of the rutabagas used in Canada, all sold in the fresh market. Canadian consumption of rutabaga declined by about 10% in the 1980s, perhaps as consumers acquired familiarity and preference for other vegetables (Coleman et al. 1991). Commercial rutabagas are grown across Canada, with Ontario and Quebec as the major producers (Anonymous 1992a). It may be noted that statistics for rutabaga in reports from Statistics Canada and provincial ministries usually include turnip (B. rapa subsp. rapa), which is not distinguished.


Rutabagas perform well on a wide range of soil types, although a loam soil is best. They do not require rich soils. In fact, excessive organic matter or soils high in nitrogen cause poorly shaped vegetables. Lack of boron produces a physiological disorder called brown heart, characterized by brownish, water-soaked patches in the flesh. These patches become more abundant as the rutabaga swells. Application of boron is needed on soils low in soluble boron or with a pH higher than 6.5 (Cutcliffe and Gupta 1987; Nonnecke 1989).

Climate

Rutabaga is a cool-season vegetable that can be cultivated throughout Canada. The optimum germination temperature is 15°C, with germination occurring as low as 5°C. The best growing temperatures are 15–20°C. Sustained mean temperatures above 25°C cause the roots to grow too quickly and become cracked and unshapely. To avoid high temperatures, commercial rutabagas are grown in cooler parts of Canada and are sown as early as possible. If the soil moisture remains near field capacity, rutabagas may become too large (in excess of 12–14 cm in diameter), rough, and cracked, rendering them unmarketable. In most parts of Canada supplemental irrigation is usually not needed unless the crop is grown in sandy soils. However, irrigation is essential in southwestern Alberta and some parts of British Columbia. In Ontario, good drainage is important because of increased precipitation and heavier soils (Anonymous 1988a; Nonnecke 1989).


Rutabagas are propagated by seeds. Large rutabaga seeds germinate faster and may mature 5–6 weeks earlier than small seeds. Therefore, hand-screening of seeds is recommended to maintain uniformity of size within rows. Seeds are direct-seeded in the soil, with early crop rutabagas sown as soon as the soil can be worked. Transplants are useful if early crops are desired or if hot summer weather in the region may interfere with the developing roots. Frequent shallow cultivation is beneficial to reduce competition from weeds (Anonymous 1988a; Nonnecke 1989). Mansour and Baggett (1985b) discussed commercial seed production of rutabaga.


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Harvest and storage

The quality of rutabagas is much improved if they are fully mature or exposed to a slight frost before harvesting. If early seeded rutabagas are left in the field until late fall, the roots become fibrous and woody. Commercial rutabagas are usually harvested mechanically. The harvesters remove the tops, dig up the rutabagas, and shake off loose soil. Care must be taken to minimize damage, because bruising reduces storage life. In preparation for storage the tops are trimmed to within 1 cm of the root, and the bottom taproot and all fibrous side roots are removed. For storage, rutabagas are piled up to 4 m deep over slatted floors with forced-air circulation. Perforated plastic sheeting is placed horizontally every 45 cm to help reduce moisture loss. The storage temperature is held close to 0°C with a relative humidity of at least 90%. Under ideal conditions rutabagas will keep for 6 months without the need for sprout inhibitors. In Atlantic Canada the roots are commonly washed. In Ontario they are frequently waxed to prevent moisture loss. Hot-waxing ensures a longer supermarket shelf life. Waxed rutabagas must be kept at lower temperatures as they spoil quickly. Alternatively, rutabagas are place in perforated plastic bags and will keep for 4–6 weeks at room temperature (Anonymous 1988a; Nonnecke 1989).

Example cultivars

Altasweet, Marian Swede, The Laurentian, Purple King, Thompson Laurentian, York Swede. Malo and Bourque (1992) described recent cultivar trials in Montreal. Bettencourt and Konopka (1990) listed institutions in various countries conserving rutabaga germplasm. Anonymous (1981) described genetic diversity and conservation requirements for rutabaga. Facciola (1990) provided an extensive description of rutabaga cultivars available in the United States.

Problems and potential Rutabaga is subject to a variety of disease and pest organisms (Nonnecke 1989). It is advisable to rotate this vegetable on a 3–4-year cycle to reduce the buildup of pathogens. Rutabaga is a minor crop in Canada and domestic consumption and amount exported have decreased in the last decade. Virtually all the rutabaga consumed in Canada is grown domestically, so there seems little chance of this crop expanding in production.

Selected reference Anonymous 1988a.

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Brassica oleracea crops

Description and taxonomy The taxonomy of B. oleracea is contentious. There are distinctive forms, but there are also intergrading variants that have resulted from domestication. Moreover, the status of many Brassica scientific names requires study to determine priority. Because of these uncertainties, some authors avoid formal scientific names for groups, but recognize them informally, often with the same names (Bailey and Bailey 1976; Huxley et al. 1992). For example, cauliflower and related forms are called the “Botrytis group” instead of var. botrytis. We have chosen to follow a formal taxonomic system (Schultze-Motel 1986), but the corresponding informal names are also often given (see “Genus notes”). The wild form of B. oleracea is subsp. oleracea (Schultze-Motel 1986; Snogerup et al. 1990). Its native distribution is along the coasts of northern Spain, western and northern France, and the British Isles, and in Helgoland in Germany (Snogerup et al. 1990). This perennial herb has a strong but not tuberous taproot and a stem that becomes Common Cole Crops

Broccoli

Kohlrabi

Cauliflower

Cabbage

Brussels sprouts

Kale and Collards


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woody at the base. It is found on limestone and chalk cliffs, on scree, and on grassy slopes and among shrubs. Close morphological similarities have been noted between the western European forms of subsp. oleracea and primitive cultivated forms (Snogerup et al. 1990). The most likely area of origin of the cultivated forms is the Mediterranean. The Greek writer Theophrastus (372–286 B.C.) described three cole crops: one with crisped, ruffled, or curled leaves; another with smooth leaves; and a wild, very pungent form. The curly-leaf forms, or kales, are considered by many authors to be the most primitive of the cultivated forms, resembling the wild form, var. oleracea (Prakash and Hinata 1980; Gray 1989). Cabbage, savoy cabbage, cauliflower, and kohlrabi may have been familiar to ancient Romans. By the Middle Ages white, red, and savoy cabbage, various kales, kohlrabi, and cauliflower were known in the Mediterranean and much of Europe. Cauliflower was initially difficult to grow in northern Europe until the Dutch produced seeds from plants overwintered under glass. Brussels sprouts gained popularity in the 1800s. Broccoli, known in Europe since the 16th century, became popular only after development in the United States in the 1930s. Cabbage was introduced to North America in 1541 by Jacques Cartier. Late cabbage, used for sauerkraut, had its origin in Germany. Cultivated forms of B. oleracea now are significant human foods throughout the world (Nonnecke 1989).

Cauliflower

Names Scientific (Latin) name: Brassica oleracea L. var. botrytis L. English common name: cauliflower French common name: chou-fleur (m)

Description and taxonomy The term cauliflower is a combination of the Latin caulis (stem) and flore (flower), which reflects the edible inflorescence. The edible portion of broccoli, another variant of B. oleracea, is also the inflorescence. Cauliflower and broccoli are quite similar. The inflorescence or flower head of cauliflower is white or purple, and this marketable part is called the “curd.” Broccoli is the blue-green, immature inflorescence of the plant, which includes the stalks and young flower buds. It differs from early cauliflower cultivars, which are actually undifferentiated flowers

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that abort prior to flowering and production of the “curd” (Gray 1989). During the first year, cauliflower heads remain functionless, usually only forming fertile flowers after exposure to low temperatures in storage, although flowering can be induced by special temperature treatment (Nonnecke 1989). Cauliflower is known only in cultivation. Its origin as a crop is obscure and is intertwined with that of broccoli. Likely it originated directly from the wild B. oleracea var. oleracea, rather than from other cultivated forms. Records of cauliflower go back to the 6th century A.D. By the 12th century in Spain, the Moors had selected three different types. By the Middle Ages, both purple and white types were known, including the Erfurt cauliflower, from which the modern North American Snowball varieties were developed. Names such as “white-sprouting broccoli” and “heading broccoli” are still applied to forms of cauliflower in Europe (Gray 1989).

Uses Cauliflower is employed as a fresh vegetable in salads or by itself. It is cooked as a vegetable and is added to stews, casseroles, and soups, and to meat and seafood dishes. It is also a common component of mixed pickles. Example recipes

Cauliflower in rosemary-scented tomato sauce (Levy 1987) Cauliflower quiche with onion and gruyère cheese (Levy 1987) Cauliflower velouté soup with broccoli (Levy 1987) Copenhagen-style cauliflower soup (Morash 1982) French curried cauliflower (Levy 1987) Italian-style cauliflower salad (Morash 1982) Lamb with cauliflower (Kreas me Kounoupidi) (Morash 1982) Marbleized cauliflower and broccoli mold (Morash 1982) Spicy cauliflower (Morash 1982)

Importance World annual production of cauliflower often exceeds 4 000 000 t (Nonnecke 1989), about half of this produced in Europe (Hinton 1991). In Canada domestic production represents about half of the total consumed. Most Canadian cauliflower is grown in Ontario and Quebec (Coleman et al. 1991).


Cauliflower does best in deep well-tilled soil, high in organic matter. It thrives in muck soils where even moisture is supplied. The pH should be 6.0–7.5. Cauliflower is sensitive to low levels of boron in the soil, associated with browning of stem tissue and poor crop formation.


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Climate

Cauliflower is one of the more difficult vegetables to grow successfully. Temperature is regarded as the most important factor; it tolerates 4–38°C and grows well from 7–29°C; its optimum temperature is 27°C. The temperatures that produce the best crops are 15–20°C. Low temperatures just above 0°C, up to the seven-leaf stage, may prevent heading (Nonnecke 1989). The warmer the mean temperature the longer cauliflower remains vegetative, without forming marketable heads. Cultivars are grown that respond to the specific variations of the seasons and particular climates.


Propagation of cauliflower is by seed. Direct seeding is possible but is considered risky in commercial production. Normally, early cauliflower is sown indoors and then transplanted outside while temperatures are still cool. Cauliflowers are best sown in individual plug or cell trays or peat pots so that root loss is minimized during transplanting. Transplants with four or five true leaves and an age of 4–5 weeks perform best. It is important to promote slow, steady growth with no setbacks caused by water stress. Most growers sow seed in successive plantings 1 week apart so that seedlings can be transplanted regularly, which avoids loss of an entire crop from unfavorable weather. Many Canadian growers raise their own transplants, although field-grown, bare-root transplants are available from Georgia. Late or autumn cauliflowers are established outdoors in seed beds or flats. For outdoor plantings, it is advisable to treat seeds for root maggots. For commercial transplants it is important to produce seedlings of uniform size for a standard crop. Cauliflower can be grown in plastic tunnels for crop production as early as late June in some areas (Anonymous 1988a; Nonnecke 1989). To avoid buildup of diseases and pests Brassica crops should not be grown on the same soil more than once every 3 or 4 years. Commercial cauliflower seed production was discussed by Jarmin and Thornton (1985a). Most cultivars of cauliflower require blanching to produce quality curds that do not turn yellow. Blanching is done by tying the upper leaves before the heads are the size of a teacup. The process requires 3–4 days in hot weather but may take 8–12 days in cool weather. Some newer cultivars have more perpendicular main leaves requiring less tying (Anonymous 1988a). Purple-headed cultivars are not blanched. Experiments were conducted on winter production of cauliflower in coastal British Columbia by the Agriculture and Agri-Food Canada Research Station in Agassiz (Maurer 1983). Frost-resistant cultivars developed in Holland and Great Britain (where they are marketed as “broccoli”) were used. These cultivars do not develop curd until after exposure to frost. Results showed that production was feasible. The optimum seeding time was mid to late July, with transplants preferred over seeds. Spacing of 38 × 90 or 33 × 107 cm proved satisfactory. Close spacing provided mutual protection from

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winter winds. Snow cover protected the plants, and additional wind barriers are recommended. Frosts to –14°C in January were tolerated. Plants that were subject to winter flooding did not survive. In the trial area, harvests of different varieties were made from March to May. Harvest and storage

All cauliflower is hand-harvested. In commercial operations the heads are usually cut (with a few leaves still attached for better protection), film-wrapped, and packaged in the field. Early cauliflower generally produces smaller heads than late cultivars. Preference is given to heads that are 15–25 cm in diameter, though some can exceed 30 cm. Heads less than 10 cm in diameter are unacceptable. Cauliflower is usually picked in cool weather so that hydrocooling is not necessary before storage. The crop is stored at 0°C with a relative humidity of 95%. Ventilation is needed because buildup of CO2 to more than 5% causes problems, including a yellowish-gray color, soft tissue, and a strong odor after cooking. Under ideal conditions, the heads can remain in storage for 4–6 weeks. Cauliflower destined for processing is quickly cut and sorted and either frozen or pickled (Anonymous 1988a; Nonnecke 1989).

Example cultivars

Early cultivars: Cashmere, Early Snowball A, Snow Crown. Main season and late cultivars: Andes, Dominant, Incline, Siria, Snowball E Self-blanching, White Rock, White Sails, White Top. Purple-headed cultivars: Burgundy Queen, Violet Queen. Broccoli/cauliflower cross: Alverda (often called “broccoflower”). Green-curded cauliflower, such as Alverda, originated in northeastern Italy and has been available in European seed catalogs for years. A bright-orange, unreleased cultivar of cauliflower has been developed at Cornell University’s New York State Experimental Station in Geneva. This selection has 100 times more carotene than white cauliflowers (Cook 1991). (The human liver converts carotene to vitamin A.) Malo and Bourque (1992) described cultivar trials of cauliflower in Montreal. Facciola (1990) provided an extensive description of cauliflower cultivars available in the United States. Institutions in various countries storing cauliflower germplasm are listed by Bettencourt and Konopka (1990). Genetic diversity and conservation requirements for cauliflower were described by Anonymous (1981).


Mark Twain noted that “Training is everything. The peach was once a bitter almond; cauliflower is nothing but cabbage with a college education.”

Problems and potential Cauliflower is subject to various diseases and pests, which should be controlled (Anonymous 1988a; Nonnecke 1989). This vegetable is more sensitive to its growing environment than many others,


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especially to temperature. The following problems can develop because of environmental factors (Yamaguchi 1983): Ricey heads. If plants receive too much sun and heat after the curds form, the curd separates into tiny divisions resembling grains of rice. The defect increases during periods of rapid growth or with excessive application of nitrogen fertilizer. Buttoning. Plants form tiny heads if the transplanted seedlings are too mature or if weather arrests growth. Leaves in curds. As a result of warm temperatures after the curd forms, small leaves develop in the curd as the plant returns to the vegetative stage of growth. Green curds or discoloration. This color is caused by excessive exposure to sunlight of the curd. Cauliflower is a minor crop in Canada. The chief difficulty is that the domestic supply is available only from July through October. The crop must be imported throughout most of the year to satisfy demand. Maurer (1983) demonstrated that it was possible to grow winter cauliflower in coastal British Columbia, with crop harvests from March through May. It was noted that production of overwintered cauliflower would provide local growers with an off-season cash crop and that the product could be marketed in other parts of Canada. There is little potential for increased production of summer cauliflower unless a longer method of storage can be found.

Selected references Anonymous 1988a; Maurer 1983; Nonnecke 1989; Cook 1991.

Cabbage

Names Scientific (Latin) name: Brassica oleracea L. var. capitata L. English common name: cabbage [Includes red and green cabbage] French common names: chou (m), chou pommé (m)

Common cabbage

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Also: chou cabus, chou blanc, chou vert, chou rouge and Scientific (Latin) name: Brassica oleracea L. var. sabauda L. English common names: Savoy cabbage French common name: chou de Savoie (m) Also: chou de Milan, chou frisé

Description and taxonomy Taxonomists have often distinguished between the common cabbage (var. capitata) and savoy cabbage (var. sabauda) as already mentioned in “Genus Savoy cabbage notes.” However, for convenience, both the common green and red cabbages and savoy cabbage will be dealt with here. Cabbage is a biennial plant. The first year of growth produces the tightly closed ball of leaves called the “head.” Cultivars have been selected that have differently shaped heads, including round or ball-shaped, pointed, conical, and drumhead. Leaf color may be green, purple, or red. Leaves may be smooth, or crinkled as in the savoy cabbages. Cultivars have been selected for fresh market, late or storage market, and for processing or use for sauerkraut. Cabbage is an ancient vegetable derived from primitive kales (Prakash and Hinata 1980). It became popular when the ancient Romans, or more likely the Celts, spread it throughout Europe and Britain. The crumpled-leaved savoy cabbages became popular in Britain at a later period. Jacques Cartier brought cabbage to North America in 1541. Later explorers and colonists also imported it, and by the 1700s both native people and the colonials were growing this vegetable (Nonnecke 1989; Pritchard and Becker 1989).

Uses Cabbages are used as food in many ways: in salads, pickles, and as a raw and cooked vegetable. Cooked cabbage leaves are stuffed with various combinations of meat, sauce, and other vegetables to make tasty cabbage rolls. Cabbage is the main constituent of the popular German dish sauerkraut. Example recipes

Cabbage loaf (Morash 1982) Cabbage tart with caraway seeds (Levy 1987) Cabbage with apples and cider (Levy 1987) Creamed-braised cabbage with leeks (Levy 1987) Layered cabbage and mushroom gratin (Levy 1987) Marinated red cabbage relish (Morash 1982) Red cabbage and mango with ginger (Schneider 1986) Russian-style hearty cabbage soup (Morash 1982) Stewed red cabbage with Italian sausage (Morash 1982)


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Sweet cabbage strudel (Morash 1982) Whole stuffed cabbage (savoy) (Morash 1982)

Importance Cabbage is the most important vegetable of the Cruciferae (mustard family). World production often exceeds 35 000 000 t (Pritchard and Becker 1989), about half of this in Europe (Hinton 1991). A small percentage of the Canadian cabbage crop is processed, while most is used fresh. Domestic cabbage production is concentrated in central Canada with the largest volume produced in Quebec. Cabbage production and consumption declined during the 1980s in Canada (Coleman et al. 1991).


Cabbages destined for early market are best grown on sandy soils that become warm early in the season. Longer-growing storage cabbages are cultivated on muck or heavy loam soils. The pH should between 6.0 and 7.5. Soils high in organic matter will retain moisture longer in areas susceptible to dry periods (Nonnecke 1989).

Climate

Cabbage is adapted to cool temperatures, optimally 15–20°C. Cold-hardened plants can withstand –10°C for short periods. Juvenile plants exposed to temperatures below 10°C for 5–6 weeks will begin to flower; the lower the temperature, the shorter the time required. Growth is arrested when temperature remains above 25°C. Cabbage is not photoperiodically sensitive to daylength. This vegetable requires a regular supply of water so irrigation is needed during dry periods (Yamaguchi 1983; Nonnecke 1989).


Cabbage is propagated by seed. Early cabbages are grown indoors and transplanted after 4–6 weeks. Root damage is minimized by growing seedlings intended for transplanting in individual cell packs or pots. Bare-root transplants may also be available from the southern states, particularily Georgia. Later varieties can be direct-seeded in the field, but most growers still use transplants because wet spring weather can cause soil crusting, resulting in uneven seedling emergence. Multiple heads (3 or 4 per stem) are a sign of weather stress. It is important to time transplanting to avoid the low temperatures that cause flower initiation. Crop rotation is recommended, on a 3- or 4-year interval, to avoid buildup of diseases and pests of Brassica crops (Anonymous 1988a; Nonnecke 1989). Commercial cabbage seed production was discussed by Jarmin and Thornton (1985a).

Harvest and storage

Cabbages destined for the fresh market or storage are hand-harvested to avoid damage to the heads. Mechanical aids are used to assist with sorting, packing, and transporting the crop. Processing cabbages are generally machine harvested. The harvester cuts the heads from the stem and places them in trucks for transport to the processor. Heads

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of cabbage can withstand some frost, although cultivars differ in tolerance. The inner, sensitive leaves may be damaged by frost and turn brown, while the outer leaves appear healthy. Cabbage is stored at 0°C and a relative humidity of 90% or more. Cabbages destined for long-term storage have their outer leaves removed. The heads of white and red cabbage can be stored in good condition for at least A primitive cabbage cultivar 6 months. Savoy cabbage will only store for about 3 months (Anonymous 1988a; Nonnecke 1989; Pritchard and Becker 1989). Recent storage trials of cabbage cultivars were described by LeBlanc and Thébeau (1990a). Example cultivars

Early cabbage: Charmant, Early Jersey Wakefield, Flash, Golden Acre, Parel, Polar Queen, Salarite, Stonehead. Late or storage cabbage: Bartolo, Blue Pak, Danish Ballhead, April Green, Jumbo, Large Flat Dutch, Lennox, Prime Choice. Processing and sauerkraut cabbage: Atria, Little Rock, Roundup. Red cabbage (fresh market): Mammoth Red Rock, Pierrete, Red Acre, Red Debut, Ruby Ball, Rodon, Super Red. Savoy cabbage: Canada Savoy, Chieftain Savoy, Primavoy, Spivey. Ornamental cabbage (used in flower gardens): Osaka Mixed, Red Peacock, White Peacock. Cabbage cultivar trials in Montreal were reported by Malo and Bourque (1992). Cabbage breeding was discussed by Dickson and Wallace (1986). Facciola (1990) provided an extensive description of cabbage cultivars available in the United States. Bettencourt and Konopka (1990) listed institutions in various countries that store cabbage germplasm. Genetic diversity and conservation requirements for cabbages were described by Anonymous (1981).


In 1541, Jacques Cartier introduced cabbage to Canada on his third voyage. By contrast, the first written record of cabbage in the United States is 1669. The derogatory term “kraut” was applied to German soldiers during the Second World War because of the traditional liking of Germans for sauerkraut.

A curious conical cabbage

Problems and potential Cabbage is subject to a number of diseases and pests. A crop rotation of 3 or 4 years is recommended (Anonymous 1988a).


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Cabbage is the seventh most valuable fresh vegetable in Canada. Over the last decade, both demand and production have declined, although increasing amounts are exported. About 82% of all cabbage used in Canada is produced domestically (Coleman et al. 1991). There is potential to increase cabbage production to meet nearly all the Canadian demand, because this vegetable stores well for 6 months.

Selected references Nonnecke 1989; Pritchard and Becker 1989.

Brussels sprouts

Names Scientific (Latin) name: Brassica oleracea L. var. gemmifera DC. English common name: Brussels sprout(s) French common name: chou de Bruxelles (m)

Description and taxonomy For the most part, “Brussels sprouts” and “Brussels sprout” are used interchangeably to refer to the plant producing this vegetable. Brussels sprouts are known only in cultivation. This vegetable resembles small cabbage heads (called “sprouts”) and is produced in the axils of the leaves on the main stem. Sprouts first appear in the lower leaf axils and develop in higher leaf axils in sequence towards the stem tip. The earliest record of Brussels sprouts dates back about 500 years. This vegetable was developed in the cool region of northern Europe. It likely mutated from savoy cabbage (B. oleracea var. sabauda). When the head of savoy cabbage is removed, the plant develops little heads in the leaf axils. Writings from 1587 described the “new cabbage” and associated it with the city of Brussels. Its use spread across temperate Europe where it became popular because it continuously produced miniature cabbages throughout the growing season. It was 1925 before Brussels sprouts were grown commercially in North America, in Louisiana (Nonnecke 1989).

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Uses Brussels sprouts are well known as a cooked vegetable, most commonly served as a separate dish. They are also added to soups, stews, or casseroles. Example recipes

Brussels sprouts Polonaise (Morash 1982) Brussels sprouts and chestnut soup (Morash 1982) Brussels sprouts baked in Mornay sauce (Levy 1987) Brussels sprouts with chestnuts (Morash 1982) Brussels sprouts with creamy mustard-sage sauce (Levy 1987) Brussels sprouts with maple syrup (Ornish 1990) Cornish hens stuffed with Brussels sprouts (Morash 1982)

Importance Brussels sprouts is a minor crop in Canada, worth several millions of dollars annually. Domestic production of Brussels sprouts represents about half of the total product consumed in this country. Almost all Canadian-produced Brussels sprouts are processed here. Brussels sprouts production increased significantly in Canada in the 1980s (Coleman et al. 1991).


Brussels sprouts requires a pH of 6.0–7.5. Early crops are usually grown on lighter soils and later crops on heavier soils. Brussels sprouts performs well on soils high in organic matter. Additional applications of nitrogen may be beneficial. The micronutrients boron and molybdenum should be measured and adjusted in the soil if necessary. Tests in Prince Edward Island showed that soils used for Brussels sprouts for 20–25 years where boron (B) was regularly applied did not have a damaging buildup of the chemical. In fact, the residual effect of B was short-lived with leaf tissue B concentration decreasing from 123 to 40 ppm at a rate of 8 kg/ha only 1 year after application. Recommended application rates are no higher than 2 kg/ha (Gupta and Cutcliffe 1988).

Climate

Brussels sprouts are more tolerant of cold weather than most other members of Brassica oleracea. Optimum temperatures are 15–18°C for the growing season. The best sprouts are produced during cool autumn temperatures, especially in maritime areas. The plants can tolerate temperatures as low as –10°C. Brussels sprouts is a heavy user of water and if natural rainfall is limited, irrigation must be provided. However, the plant is susceptible to damage from flooding so that adequate drainage must also be available (Nonnecke 1989).


Brussels sprouts are propagated by seeds. While direct seeding is possible, transplants are preferred. The seedlings should be placed in the field 4–6 weeks after germination, which is especially important


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for early crops. Direct seeding can be used for late summer and fall crops, but protection against flea beetles, which readily feed on the young seedlings, is important. If the plants are irrigated it may become necessary to cultivate the soil between rows to improve drainage. Crop rotation is recommended, on a 4-year cycle, to reduce buildup of disease and pests (Anonymous 1988a; Nonnecke 1989). Commercial Brussels sprouts seed production was discussed by Jarmin and Thornton (1985a). Harvest and storage

To encourage the upper shoots to develop, Brussels sprouts are topped by pinching out the centre of the growing plants in early to mid September. Studies of the cultivar Jade Cross have shown that topping is best when sprouts first develop on the seventh whorl of leaves. Commercial growers generally harvest Brussels sprouts by machine. Some self-propelled combines cut and quickly remove the stalks. Other machines cut and pick the entire plants, which are then moved to packing houses where they are fed through strippers to remove the sprouts. The crop apparently tastes sweeter if it has been subjected to frost before harvest. The sprouts are either chilled to 0°C with relative humidity of 90% or vacuum cooled to about 2°C and then packaged and topped with ice. Under ideal storage conditions they can be maintained for 3–5 weeks. After a time the outer leaves begin to yellow, indicating loss of quality. Controlled storage with 5–7% CO2 slows deterioration, but some O2 must remain in the atmosphere to prevent extensive damage (Anonymous 1988a; Nonnecke 1989).

Example cultivars

Green sprouts: Dolomic, Jade Cross, Long Island Improved, Prince Marvel, Starter, Valiant. Red sprouts: Rubine. Cultivar trials of Brussels sprout were reported for the provinces of Prince Edward Island (Stevenson and Cutcliffe 1988), New Brunswick (LeBlanc and Thébeau 1990c), and Quebec (Malo and Bourque 1992). Facciola (1990) provided an extensive description of Brussels sprouts cultivars available in the United States. Bettencourt and Konopka (1990) listed institutes of the world that store germplasm of Brussels sprouts. Genetic diversity and conservation requirements for Brussels sprouts were described by Anonymous (1981).


In their humorous treatment, Beard and McKie (1982) gave the following account of Brussels sprouts. In medieval times, this was thought to be a source of “fetid humors” and was called “the devil’s hell-ball.” It was officially declared anathema in Pope Boniface VII’s bull of 1304 (“De Gustibus Detestabilis”) and was actively suppressed for several centuries.

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Problems and potential Brussels sprouts is susceptible to diseases and pathogens similar to other cole plants (Anonymous 1988a; Nonnecke 1989). Although a minor vegetable in Canada, in recent years there has been some increase in production as consumer acceptance has risen.

Selected references Anonymous 1988a; Nonnecke 1989.

Kohlrabi

Names Scientific (Latin) name: Brassica oleracea L. var. gongylodes L. English common name: kohlrabi French common name: chou-rave (m)

Description and taxonomy The edible portion of this herbaceous biennial is the swollen, spherical part of the stem above soil level. Leaves produced on the surface of this structure give a distinctive appearance. It is this turnip-shaped swollen stem, a tuber, that leads to the name kohlrabi, a german word from Kohl, meaning cabbage, and Rabi, turnip (actually it is neither). Kohlrabi is known only in cultivation. This crop was first recorded in northern Europe about 500 years ago. It is thought to have been derived from either the marrow-stem kale (B. oleracea var. medullosa Thell.) or directly from wild cabbage (B. oleracea subsp. oleracea) (Nonnecke 1989). It was recorded in the United States in 1806. Kohlrabi is widely consumed in Germany, England, and the eastern Mediterranean countries (Nonnecke 1989).

Uses Kohlrabi tubers are eaten as a cooked and raw vegetable, and the leaves are also employed as a vegetable.


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Example recipes

Butter-braised sliced kohlrabi (Morash 1982) Creamed kohlrabi (Organ 1960) Kohlrabi Chinese style (Richardson 1990) Kohlrabi dumplings (Gnocchi) (Morash 1982) Kohlrabi soup (Morash 1982) Kohlrabi with anchovy and olive dressing (Schneider 1986) Lamb-stuffed kohlrabies (Morash 1982) Stuffed kohlrabi (Organ 1960) Swedish meatballs with kohlrabies (Morash 1982) Whipped kohlrabi and potato (Morash 1982)

Importance Kohlrabi is more important in Europe than North America. In Europe, more than 40 000 t of kohlrabi are often produced annually (Hinton 1991). Very little is grown in Canada, and production statistics are unavailable.


Kohlrabi grows best on heavy soils rich in organic matter. The soil pH should be 6.0–7.5.

Climate

Kohlrabi is a cool-season plant. Sustained temperatures of 10°C or less for 1 week will cause the plant to bypass tuber production or leads to premature flowering. Sensitivity to cold temperatures begins at germination. Exposure of even young plants to –1 to 1°C initializes vernalization, leading to flowering. To ensure tender tubers, a steady supply of water is essential. However, the plants must be grown on soil with good drainage to prevent damage from waterlogging (Nonnecke 1989).


Kohlrabi is propagated by seed. It is usually direct-seeded in warmer geographical areas. Early crops in colder climates are transplanted after the probability of cool temperatures (below 10°C) have passed, to avoid bolting. Sequential sowing of seed can provide a crop throughout the growing season. Commercial production of kohlrabi seed was discussed by Jarmin and Thornton (1985a). A rotation of 3 or 4 years is recommended to reduce the buildup of disease and pest organisms.

Harvest and storage

Kohlrabi is hand-harvested when the tubers are 5–7 cm in diameter. Harvested tubers are kept below 5°C, with a relative humidity of 95% to prevent wilting or development of tough flesh. Moisture loss is reduced by packing in perforated film. Kohlrabi held a 0°C will store for 1 month.

Example cultivars

Green/white kohlrabi: Early White Vienna, Grand Duke, Super Schmelz (Giant White). Red/purple kohlrabi: Blaro, Early Purple Vienna, Purple Speck.

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Some of the newer cultivars are not as prone as older ones to becoming woody or to bolting. Super Schmelz (also known as Giant White) produces, under ideal conditions, tubers weighing almost 10 kg. Facciola (1990) provided an extensive description of kohlrabi cultivars available in the United States. Bettencourt and Konopka (1990) listed institutions in various countries conserving kohlrabi germplasm. Genetic diversity and conservation requirements for kohlrabi were described by Anonymous (1981).


The earliest forms of kohlrabi were probably from the southern areas of Europe such as Italy and Greece. These had a smaller swelling of the stem base and more closely resembled the supposed ancestor, the marrow-stemmed kale (B. oleracea var. medullosa). Two varieties of this primitive form were used in France in ornamental gardening, one with finely dissected leaves and the other with leaves resembling those of artichoke. The more highly improved forms, used as a vegetable, were likely selected in northern Europe (Hedrick 1972).

Problems and potential Kohlrabi is susceptible to a variety of diseases and pests, particularily black rot and bacterial soft rot, which are common storage and marketing diseases (Nonnecke 1989). Kohlrabi is likely to remain a little-grown crop, of most interest to Canadians of European and especially German origin, who have acquired a taste and tradition of using it.

Selected reference Nonnecke 1989.

Broccoli

Names Scientific (Latin) name: Brassica oleracea L. var. italica Plenck English common name: broccoli French common name: brocoli (m) and


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Scientific (Latin) name: Brassica ruvo Bailey English common name: broccoli raab Also: spring raab French common name: rapini (m) [Broccoflower, the hybrid of broccoli and cauliflower, = brocofleur (m)]

Description and taxonomy The term broccoli, from the Italian plural broccolo, which refers to the flowering top of a cabbage, came originally from the Latin brachium, meaning arm or branch. Broccoli is known only in cultivation. It likely originated from wild B. oleracea var. oleracea, although some authors believe that both broccoli and cauliflower may be descended from the wild species B. cretica Lam. (Gray 1989). The origin of broccoli is confused with that of cauliflower. Since Roman times the two crops have frequently not been distinguished. Even in modern times the two crops are unclearly identified, depending where the crop is grown. For example, in North America broccoli refers to the green-sprouting form known in many parts of Europe as “calabrese.” In Britain the word broccoli has been used to denote different groups of late or perennial cauliflower. In fact, to further complicate the issue a hybrid between broccoli and cauliflower, called “broccoflower,” is now available in Canadian supermarkets. Broccoli is the immature inflorescence of the plant, including the stalks and young flower buds. This differs from early cauliflower cultivars, that are actually undifferentiated flowers that abort prior to flowering and production of a head or “curd” (Gray 1989). Accurate descriptions of broccoli were not prepared until the Middle Ages, when the English referred to sprouting cauliflower or Italian asparagus. American writers in 1806 called it green broccoli. The Americans broadened the popularity of this vegetable, which otherwise was limited largely to Italy (Nonnecke 1989). Some Canadian garden catalogs offer forms of Brassica under such names as “rapini,” “broccoli raab,” “spring raab,” and the cultivar name Rapine. These names are likely not being correctly applied. The name Broccoli raab “rapini” or “rappini” designates cultivars of B. rapa (so-called rapini)

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subsp. rapa, turnip. “Rapini” has been selected for its edible greens. The name “spring raab” or “broccoli raab” applies to cultivars of B. ruvo Bailey (sometimes listed as the Ruvo group of B. rapa [Huxley et al. 1992], which are fast-growing annuals that form loose-flowering heads in the axils of the lower leaves. Both the flower heads and the leaves are eaten. Based on Canadian catalog descriptions, it would appear that the “rapini” and other such offerings are most likely B. ruvo. These cultivars are mentioned here because of their similarity of form and cultivation with broccoli.

Uses Broccoli is a well-known vegetable, eaten raw or cooked in salads and a variety of prepared meals. Broccoli raab has a more pungent and bitter taste than broccoli. It is a favorite in Italian cooking, where it adds a zesty flavor to bland foods such as mild potato and pasta dishes and holds its own with highly seasoned foods such as spiced sausage. Broccoli raab cooks faster than broccoli (2–6 min) and turns soft suddenly. To reduce the pungent flavor, it can be blanched for 1 min in boiling salted water, drained, and then cooked (Schneider 1986). Example recipes

Broccoli Bavarian (Levy 1987) Broccoli and mushroom soufflé with chives (Levy 1987) Broccoli de Rabe with spaghettini (Morash 1982) Broccoli deep-dish pizza (Morash 1982) Broccoli raab and Italian sausages (Schneider 1986) Broccoli soup (Morash 1982) Buckwheat crêpes with creamy vegetables (Levy 1987) Cauliflower velouté soup with broccoli (Levy 1987) Chicken and broccoli Mornay (Morash 1982) Piquant oriental-style broccoli raab salad (Schneider 1986) Pork chops with broccoli de rabe (Morash 1982) Quick broccoli gratin with gruyère and nuts (Levy 1987)

Importance Broccoli is a minor Canadian crop, although its value amounts to several million dollars annually. Domestic production represents about a quarter of all broccoli used in Canada. Less than 10% of Canadian-produced broccoli is processed, and the rest is used in the fresh market (Coleman et al. 1991). It may be noted that statistics for “rappini” (under B. rapa subsp. rapa) may apply to broccoli raab because of different uses of the name rappini (see “Description and taxonomy”).


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Broccoli is best adapted to well-drained soils high in organic matter, although it will grow on various substrates including light, heavy, or muck soils. Soil pH should range between 6.0–7.5 (Nonnecke 1989).

Climate

Optimum growing temperatures for this cool-season plant are 15–17°C, and a mean temperature of 24°C is considered a maximum. Broccoli is a heavy user of soil moisture, and even short periods of drought can cause disastrous crop loss. However, it is intolerant of waterlogged soils. Not only is irrigation essential during dry periods, but also adequate drainage must be provided (Nonnecke 1989).


Broccoli is propagated by seed. It matures quickly so that early and late crops are possible. Early crops of broccoli are sown indoors and transplanted outside when plants are 5–6 weeks old. Late crops can be planted directly outdoors (during May to early June in southern Canada). Heavy rains or crusted soil conditions after direct seeding may cause poor germination. Transplants should always be used on clay or clay loam soils. Large or old plants of broccoli subjected to cool temperatures (10–15°C) are likely to bolt if exposed to a period of cool weather in the field. Broccoli grown in plastic tunnels is less likely to bolt during the cool spring so that first crops can be harvested in June. Hollow stems develop in well-spaced plants or when high levels of nitrogen fertilizer are applied (Anonymous 1988a). To avoid the accumulation of diseases and pests, members of Brassica should be planted on the same land only one year out of three or four. In some cooler regions of Europe, broccoli has been adapted for greenhouse production by breeding and cultural practices. The most desired characteristics are short time to maturity (about 50–60 days) and high performance in a restricted space.

Harvest and storage

Broccoli is harvested by hand. It must be harvested before the buds open, while bud-clusters are still compact. Yellow buds or loose clusters make the crop unmarketable. The terminal head matures first (usually when it is around 15 cm in diameter) and its removal promotes the lateral heads to develop. Because the lateral heads mature unevenly, regular harvesting is required. The heads are harvested with about 15 cm of stem attached. Mechanization is used for trimming, packaging, and transporting the crop. Broccoli is a high-respiring vegetable that must be rapidly cooled, either by hydrocooling or with crushed, top-loaded ice. The heads should be cooled to 0–2°C with a relative humidity of 95%. Broccoli can be stored for 2 weeks at 2°C, or up to 3 weeks at 5°C if either O2 level is dropped to 0.5% or CO2 is raised to 10%. Water loss must be minimized in storage by applying crushed ice or wrapping (Anonymous 1988a; Nonnecke 1989). A new broccoli handling system has been developed at the Kentville Research Station of Agriculture and Agri-Food Canada in Nova Scotia. Wooden bins full of broccoli are transported to the storage facility where they are precooled. Precooling is accomplished by pumping refrigerated water (0.5°C) through the bins. The bin is

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held under refrigeration until marketing. This method reduces damage from handling, requires less labor, and delivers fresher-looking broccoli. This system is more energy efficient than those using ice because the refrigeration unit is only turned on when required (LeBlanc 1992). Example cultivars

Early season: Emperor, Galleon, Improved Comet, Packman. Main season: Cruiser, Eureka, Green Valiant, Legend, Premium Crop, Sultan. Specialty types: Italian Sprouting, Red Broccoli. Broccoli/cauliflower cross: Alverda, Brozino, Romanesco (these are sold in supermarkets as “broccoflower”). Some Canadian garden catalogs sell “rapini” or “spring raab,” sometimes with the cultivar name Rapine. Such are most likely cultivars of B. ruvo Bailey (discussed earlier), which are fast-growing annuals that form loose-flowering heads in the axils of the lower leaves. These are popular with Canadians whose ethnic origin is European, especially Italian. The cultivar Romanesco, developed in central-western Italy near Rome, is revered in Europe for its nutlike texture and sweet flavor. According to Cook (1991) this cultivar is actually a cauliflower, although it is sold as a broccoli in garden catalogs and is therefore mentioned here. Cutcliffe and Stevenson (1987) described trials of broccoli cultivars in Prince Edward Island, as did LeBlanc and Thébeau (1988a) for New Brunswick and Malo and Bourque (1992) for Montreal. World institutions conserving broccoli germplasm are listed in Bettencourt and Konopka (1990). Genetic diversity and conservation requirements for broccoli were described in Anonymous (1981).


Broccoli raab (B. ruvo) is also called turnip broccoli, which is almost a direct translation of the Italian broccolini di rapa (Halpin 1978). This vegetable is a favorite among Canadians whose ethnic background is Italian. In their humorous treatment, Beard and McKie (1982) suggested that broccoli was “... grown chiefly as (a) receptacle for Hollandaise sauce.”

Problems and potential Broccoli is susceptible to various diseases and pests. If subjected to cool temperatures it may bolt, which reduces the number of marketable heads (Anonymous 1988a; Nonnecke 1989). Broccoli is a minor crop in Canada, although it is popular as a fresh vegetable year-round. The domestic market only supplies broccoli for about 4½ months of the year. There is little chance for expanding production unless longer-term storage methods can be


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developed. Alternatively, greenhouse production could open up new markets in Canada (Nonnecke 1989).

Selected references Anonymous 1988a; Nonnecke 1989; Cook 1991.

Kale

Names Scientific (Latin) name: Brassica alboglabra L. English common name: Chinese kale Also: Chinese broccoli French common name: brocoli chinois (m) and Scientific (Latin) name: Brassica oleracea L. var. sabellica L. English common name: Scotch kale Also: curled kitchen kale French common name: chou vert frisé (m) Also: chou frisé, chou vert and Scientific (Latin) name: Brassica oleracea L. var. viridis L. English common name: kale, collard Also: borecole French common name: chou vert (m), chou cavalier (m) Also: collard

Description and taxonomy Kale is a Scottish word representing a variation of cole, from the Latin caulis (stem, cabbage). Borecole is from “boer’s cole,” i.e., peasant’s cole or cabbage. Collard is an alteration of colewort, which means cole-plant. In the United States, collards refers to noncrinkled, partially headed varieties. In northern Europe, the crinkled or curled nonheading varieties are popular.

Kale

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The name kale is applied to cultivars representing different taxonomic entities. The kales of varieties of B. alboglabra, B. oleracea, and B. rapa have been treated in different ways taxonomically. Cut- or crisp-leaved, green- or purple-leaved varieties are commonly encountered in kitchen gardens and are called kitchen kales. Tree kales produce simple straight stems that may reach 4 m in height. Some forms have undivided leaves and others develop fringed or curled foliage. Marrow-stem kales resemble tree kales, but the stem enlarges somewhat, becoming tuberous with a thick, tender-fleshed trunk. Both are used as animal fodder. Bush-kale, also known as thousand-head kale or borecole, is bushlike and up to 2 m tall. The Portugese kale is a low, compact form that has large, broad leaves with fleshy stalks and ribs. The fleshy petioles are eaten like celery. Chinese kale is a distinctive annual, grown as a potherb in Asia. In this treatment the plants are termed “kale-collards” because agronomic features are generally the same. The following plants grown for human food in Canada are included in this treatment: Chinese kale, Chinese broccoli; B. alboglabra [= B. oleracea L. var. alboglabra (L.H. Bailey) Musil] Scotch kale, curled kitchen kale; B. oleracea var. sabellica kale, borecole, collard; var. viridis [= B. oleracea L. var. acephala DC.] Kale-collards are herbaceous annuals in all but the warmest parts of Canada and herbaceous Collards biennials in warm temperate areas. They may become woody perennials in the tropics. Kale-collards are usually nonheading plants. Their terminal and lateral buds elongate during the first season. For seed production, they must be grown in areas that do not freeze. Two types of kales have been developed. The shorter, green or blue-green plants are eaten as human food, whereas the larger or tree-kales have stiff, strong leaves and are used for animal fodder. Collards produce smooth, tender foliage and are used as potherbs. A rosette of leaves developed at the stem apex is cut and used for cooking. Removing the leaves stimulates additional leaf production. Kale-collards (of var. viridis) closely resemble and were probably the earliest vegetable selected from wild B. oleracea var. oleracea, perhaps as early as 4000 years ago. Some consider these to be among the more ancient of vegetables, although their time of origin is obscure. During ancient Greek times, no distinction was made between kale and collards. The Romans introduced them to Britain and France. The Anglo-Saxons applied the name cole worts, meaning cabbage plants. These vegetables were introduced to North America by colonists in the 16th century (Nonnecke 1989).


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Uses Only the tiny, young leaves of kale can be eaten raw. More mature kale leaves must be cooked for use as a vegetable or in soups. It is said that frost makes the leaves more tender (Rhee 1979). Collards are best picked when young, fresh, and bright-green. They can be frozen for winter use (Halpin 1978). Several cultivars of flowering kale appear in various colors and are used as ornamentals; they are sold through Canadian garden catalogs. Example recipes

Beef braised with collards in beer (Schneider 1986) Calzone stuffed with kale (Morash 1982) Chinese kale salad (Buishand et al. 1986) Colcannon (vegetable dish) (Morash 1982) Collard greens with cornmeal dumplings and bacon (Schneider 1986) Collards and rice (Morash 1982) Kale and lemon (Ornish 1990) Kale pie (Morash 1982) Kale turnovers (Schneider 1986) Lamb, kale, and barley stew (Morash 1982) Lentil and collard soup (Morash 1982) Spicy collards (Schneider 1986) Turkey breast with kale (Morash 1982)

Importance Kales are grown in Ontario and Prince Edward Island as summer crops in local market gardens. Collards are sold occasionally in local markets, largely for people of African or Caribbean ethnic origin who have learned to appreciate this vegetable. Kale-collards are minor crops in Canada. Kale is popular in some parts of Europe, which often exports several hundred tonnes annually to Canada.


Kale-collards require a pH of 6.0–7.5 and grow best in heavy soils high in organic matter. They will produce satisfactorily in a wider range of soils than most cole crops. Kale-collards require high amounts of N for leaf production.

Climate

Kale-collards are the hardiest of the cole crops, withstanding temperatures of –15 to –10°C. In Canada they are grown as a summer crop but towards the central and southern United States they become progressively a late summer to winter crop. Kale-collards require an abundant and consistent water supply. Irrigation is necessary during dry periods.

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Kale-collards are propagated by seeds. They are generally direct-seeded in warmer regions. In northern areas, early summer crops are transplanted from greenhouses or field beds. Seed production was discussed by Jarmin and Thornton (1985b).

Harvest and storage

Leaves of kale-collards should be harvested when young and tender. Collards may be harvested by cutting off the Kale entire rosette, which will stimulate more leaves to develop. For fresh market, hand-reaping is still widespread because of extensive damage that may result to the leaves from machine harvesting. If mechanical harvesters are used, they are set to cut close to the ground to obtain as much of the plant as possible. The cut stem provides a base for presenting the bunched leaves for market. Kale-collards destined for processing are generally harvested mechanically. Kale-collards respire rapidly and must be cooled to 0°C and high relative humidity. Ice is placed on the tops of shipping containers. Individual bunches destined for fresh market are packaged in perforated bags. Under ideal conditions kale-collards will store for 4–5 weeks (Nonnecke 1989).

Example cultivars

Collards (var. viridis): Champion, Flash Hybrid, Vates. Kale (var. viridis): Blue Curled Scotch, Green Curled Scotch. Kale (var. sabellica): Kale Siberian, Vates Blue Curled, Winterbor Hybrid. Chinese kale (B. alboglabra): Green Lance (this cultivar also forms edible flower heads resembling loose broccoli, hence the alternate name “Chinese broccoli”). Ornamental kales (used in flower gardens): Chidora Red, Nagoya White, Red Sparrow, White Sparrow. Bettencourt and Konopka (1990) listed institutions in many countries conserving germplasm of all the kale-collards. Facciola (1990) provided an extensive description of kale and collard cultivars available in the United States. Genetic diversity and conservation requirements for kale and collards were described in Anonymous (1981).


The “trunks” of tree kales have been made into walking sticks. The name “kale” may have originated in Scotland where this plant was used as a potherb in the Middle Ages and was known as “keal” (Hedrick 1972).

Collards


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Problems and potential Kale-collards are susceptible to various diseases and pests. Flea beetles are a particular problem for collards (Halpin 1978; Nonnecke 1989). This vegetable is likely to remain a minor crop in Canada, appealing mainly to Canadians whose ethnic background has resulted in their familiarity with it.

Selected references Halpin 1978; Rhee 1979; Nonnecke 1989.

Spinach mustard

Names Scientific (Latin) name: Brassica perviridis (Bailey) Bailey English common name: spinach mustard Also: tendergreen French common name: moutarde-épinard (f)

Description and taxonomy Spinach mustard is an annual herbaceous plant (although it may be biennial in mild climates if sown late). Brassica perviridis is sometimes known as B. rapa subsp. perviridis Bailey by some authors, or is included as part of B. campestris L. It is known only in cultivation. Spinach mustard has been selected for its edible leaves, stems, and tubers. It probably originated in eastern Asia from other oriental species. Some forms of this plant have swollen tubers, which are pickled; others produce a thin taproot and only the leaves are eaten (Halpin 1978).

Uses Spinach mustard leaves are used as a cooked vegetable. Example recipes

Salad of spinach mustard greens and avocado with sweet-hot dressing (Schneider 1986) Sausages and spinach mustard greens with spaghetti (Schneider 1986)

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Importance Spinach mustard is used to some extent in Asia and parts of the United States. Information on Canadian production of spinach mustard seems unavailable. “Mustard greens” are available on the retail market in Toronto, but because this name also applies to Brassica juncea, it is unclear which species is being marketed (Anonymous 1989).


Spinach mustard will grow on a variety of soils, but a sandy loam soil high in organic matter is best. Soil pH should be 5.5–6.5 (Halpin 1978).

Climate

Spinach mustard is more tolerant of warm summer temperatures than mustard greens (B. juncea) and will produce leaves for a longer time before bolting. A regular supply of water is beneficial (Halpin 1978).


Spinach mustard should be started in the spring or in early autumn. However, as it is more tolerant of hot temperatures than some other leafy vegetables, successive plantings are not as necessary to maintain a crop of foliage (Halpin 1978).

Harvest and storage

The leaves are ready to harvest when 10–12 cm long. They lose their tenderness if too mature. Spinach mustard will last longer than mustard greens (B. juncea) in greenhouses. Leaves of mustard greens become pungent-tasting and unpalatable in a shorter time (Halpin 1978).

Example cultivars

Spinach mustard: Green Boy, Komatsuna F1. Selections are sometimes called “Tender Green Mustard Spinach.” The cultivar Senposai Green is a hybrid between spinach mustard and common cabbage, B. oleracea var. capitata. Bettencourt and Konopka (1990) listed institutions in various countries that might conserve spinach mustard germplasm. Jarmin and Thornton (1985c) described seed production of spinach mustard.

Spinach mustard

Problems and potential Spinach mustard is susceptible to various disease and pest organisms. Crop rotation of 3 or 4 years is recommended (Tindall 1983). Spinach mustard is a minor crop in Canada. It may be grown in market gardens for local consumption. This crop is likely to remain of interest to Canadians whose ethnic origin has resulted in their familiarity with it.


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Brassica rapa crops

Name Scientific (Latin) name: Brassica rapa L.

Description and taxonomy Considerable controversy exists regarding usage of the names Brassica rapa and B. campestris. Most present-day authors agree that these names designate the same species and that the correct name is B. rapa (Oost 1986). However the name B. campestris L. is still employed by some North American taxonomists. Within B. rapa are distinctive kinds, often recognized as formal varieties. Some authors avoid formal scientific names but recognize informal groups, often essentially with the same names (Bailey and Bailey 1976; Huxley et al. 1992). For example, turnip and related forms are called the “Rapifera group” instead of subsp. rapa. Several subspecies of B. rapa are cultivated (see “Genus notes”), including the various subspecies used as vegetables and those used for oilseed production. The vegetable groups are discussed below. Brassica rapa includes annual and biennial herbaceous plants. Wild forms belong to subsp. oleifera (DC.) Metzg. (Schultze-Motel 1986), an annual or biennial with a nontuberous taproot. The wild form, which includes oilseed rape, is often separated as subsp. sylvestris (Lam.) Janchen by some authors. Truly wild forms probably may still exist today; certainly subsp. oleifera is a common weed in both Europe and North America. Brassica rapa is cultivated in North America and has successfully escaped, probably in all provinces of Canada (Scoggan 1978–1979). The wild form closely resembles those selected for their oil-containing seeds but has usually black, not red-brown or yellow seeds. Evidence suggests multiple domestication of the oilseed forms. Two centres of origin have been proposed. The European forms are biennials and had their origins in the eastern Mediterranean region. Annual forms come from eastern Afghanistan and adjoining Pakistan, considered to be another major centre. The time and place of domestication is unknown but it occurred in the pre-Classical era as there are ancient Arab and Hebrew names for the crop. Sarson, subsp. trilocularis (Roxb.) Hanelt, was used in ancient India since 2000–1500 B.C. (Simmonds 1976).

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In addition to subsp. rapa, turnip, which is discussed later, B. rapa has several subspecies that are used as vegetables.

Oriental cabbages

Names Scientific (Latin) names: Brassica rapa subsp. chinensis (L.) Hanelt subsp. narinosa (Bailey) Hanelt subsp. nipposinica (Bailey) Hanelt subsp. pekinensis (Lour.) Hanelt The “Oriental cabbages” include these four subspecies of B. rapa and are dealt with below collectively. The English and Asian common names are listed in the following table. All are annuals; subsp. chinensis may also be a biennial. Chinese mustard

French common names: subsp. chinensis: chou (B. rapa subsp. chinensis) chinois (m), pak-choï (m) Also: bok-choy subsp. narinosa: savoie de Chine (m) subsp. nipposinica: mizuna (m) subsp. pekinensis: chou chinois (m), nappa (m), pé- tsaï (m)

Description and taxonomy In China, subsp. pekinensis is referred to as “large white cabbage,” whereas the subspecies chinensis, narinosa, and occasionally nipposinica are termed “small white cabbage.” They are indispensible leaf vegetables in China, Japan, Indonesia, and Malaysia. These small white cabbages do not have a strict cabbagelike head. Subsp. chinensis includes selections with loosely packed leaves. Subsp. narinosa has a flattened rosette of leaves, at least early in its development. Subsp. nipposinica more closely resembles mustard greens (B. juncea) but is discussed here because agronomically its growth and production is the same as the other “Oriental cabbages.” There are two morphological types of subsp. nipposinica. The “Mizuna” group consists of deeply dissected, bipinnate leaves; the “Mibuna” group has slender, entire leaves (Nishi 1980). The plants are known only in cultivation. There is no evidence that forms of B. rapa were cultivated in ancient China. The oilseed forms may have reached Japan as recently as 200 years ago. The Oriental vegetable forms probably evolved in China from oilseed forms, by selection for leafiness. A cabbagelike plant was mentioned in writings from about A.D. 300. Opinions differ as to whether subsp. pekinensis


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developed from subsp. chinensis or whether both groups were selected independently (Hamers 1989). Subsp. nipposinica and narinosa were selected for increasing leaf numbers, whereas subsp. chinensis and pekinensis were selected for increased leaf size and head formation. Parallel morphological forms to all these have been selected in B. oleracea in Europe (Simmonds 1976). Chinese cabbage was introduced to North America during the 1800s (Nonnecke 1989). Brassica rapa oriental cabbages1 Latin name subsp. chinensis (L.) Hanelt [= B. campestris L.]

English name and form Chinese mustard, celery mustard; loose head with oblong–ovate leaves

subsp. chinensis (L.) Makino; B. oleracea L. var. chinensis (L.) Prain Terrell et al. (1986), Chinensis group4; includes B. parachinensis Bailey, called chum soy] Chinese savoy; rosette with subsp. narinosa (Bailey) Hanelt dark–green leaves [= B. campestris L. subsp. narinosa (Bailey) Olssen; B. rapa var. narinosa (Bailey) Kitam. (Terrell et al. 1986)] subsp. nipposinica (Bailey) Hanelt rosette with entire or finely [= B. campestris L. subsp. nipposinica dissected leaves; side tillers (Bailey) Olssen] subsp. pekinensis (Lour). Hanelt Chinese cabbage, celery cabbage; [= B. campestris L. subsp. pekinensis tight head with broad, ovate (Lour.) Olssen; B. pekinensis (Lour.) leaves (includes the “nappa” and Rupr.; Pekinesis group4] “michihli” types)

Oriental name2 pei tsai3 (M),2 bok (pak) choy (choi)3 (C) chongee (J)

ta ko tsai, taatsai (C)

shui tsai (C), mizuna, mibuna, kyona (J), siew choy, bow sum, bok choi3 (C), pai–tsai3, won bok, wong bok, pao, hsin pei tsai (M), napa, nappa, hakusai (J)

1This

table is based on Prakash and Hinata (1980), Terrell et al. (1986), and Schultze–Motel (1986). names: M = Mandarin Chinese, C = Cantonese Chinese; J = Japanese. 3“Pei tsai” and “pai–tsai” as well as “bok choy” and “bok choi” are sometimes used interchangeably to refer to both subsp. chinensis and subsp. pekinensis. 4Groups according to Bailey and Bailey (1976) and Huxley et al. (1992). 2Oriental

Uses These Oriental vegetables are widely used in parts of Asia. Subsp. pekinensis is a heading type that has a more delicate flavor than cabbage. It is used raw in salads or boiled, stir-fried, or pickled. Subsp. chinensis has both edible leaves and leaf stalks. The leaves can be boiled and the stalks boiled or used in stir-fries. Both are used in soups. Subsp. narinosa and nipposinica are both grown for their leaves that are used raw in salads or boiled (Harrington 1978). Example recipes

Barbara Spiegel’s baked bok choy with gruyère (Schneider 1986) Bok choy fried rice with bacon (Schneider 1986) Bok choy with apple and ginger (Schneider 1986) Braised chinese cabbage (Schneider 1986) Chinese cabbage with pork (Buishand et al. 1986) Chinese lion’s head (Morash 1982) Chinese pickled cabbage (Tudge 1980)

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Hot-sweet chinese cabbage with ginger and tomatoes (Schneider 1986) Indian Jose Indonesian stir-fried vegetables (Schneider 1986) Pak-choi hotpot (Buishand et al. 1986)

Importance Chinese cabbage, 1992 Area Canada N.S. N.B. Que. Ont. Man. Alta. B.C.

Hectares 532 4 4 109 342 4 32 36

Source: Statistics Canada 1993b.

The Oriental cabbages, notably subsp. pekinensis, are cultivated worldwide and are particularily important in several Asian countries, notably Indonesia and Japan (Hamers 1989). Several thousand tonnes are grown annually in Canada, although imports exceed the domestic supply. For example, in 1991, 4754 t of domestic and 8184 t of imported Oriental cabbages were unloaded at 10 major Canadian markets (Anonymous 1992a); in 1992, 2484 t of Chinese cabbage were unloaded in these markets (Anonymous 1993a). The “nappa” and “michihli” selections are the most common Oriental cabbages found in Canadian supermarkets. “Nappa” refers to subsp. pekinensis and “bok choy” could refer to either that subspecies or to subsp. chinensis. Comparative provincial areas of “Chinese cabbage” cultivation in Canada are given in the accompanying table.


These vegetables perform best in muck soils rich in organic matter and so able to retain water. The soil pH should be 6.0–7.5. Under some soil conditions adding boron is needed to prevent physiological problems (Nonnecke 1989).

Climate

The biennials (subsp. chinensis) are hardier than the annuals. All these vegetables are cool-season plants that will vernalize readily if subjected to sustained temperatures of 5–10°C during the seedling stage. These crops are photoperiodically sensitive and will bolt in the long daylength normal to early season Canada. Optimum growing temperatures are 15–18°C. They need a constant water supply because they are high-respiring and very leafy (Tindall 1983; Hamers 1989; Nonnecke 1989).


The Oriental cabbages are propagated by seed. To avoid bolting, early crops are grown indoors and transplanted outside when mean temperatures are above 10°C. Otherwise, they are either transplanted or direct-seeded in July and harvested as a fall crop (Tindall 1983; Nonnecke 1989). Seed production of Oriental cabbages was discussed by Jarmin and Thornton (1985c).

Harvest and storage

The whole plants are cut at soil level. Heading types are harvested when the heads are firm and the outer leaves are bright green. With some cultivars, the outer leaves may be tied a few weeks before harvest to promote a tighter, upright head. The leafy cultivars are harvested while the leaves are bright and intact. Any damaged leaves are removed, and the plants are quickly hydro-cooled to reduce respiration.


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The Oriental cabbages are stored at, but not below, 0°C, with a relative humidity of 95–98%. The crop can be stored for 4–5 weeks. Trials with controlled atmosphere using O2 at 2% or CO2 at 2–5% suggested possible storage for several months (Tindall 1983; Nonnecke 1989). Example cultivars

Subsp. chinensis: Joi Choi, Lei Choi, Mei Quing Choi, Ming Choi (these selections are often listed as “pak choy” or “bok choy”). Subsp. narinosa: Mustard Tatsoi, Tah Tsai. Subsp. nipposinica: Mustard Green Spray, Tokyo Beau, Tokyo Belle. Subsp. pekinensis: nappa or napa cultivars: Burpee’s Two Seasons, China Pride, Kasuma, Springtime II. michihli cultivars: Green Rocket, Jade Pagoda, Monument. Bettencourt and Konopka (1990) listed institutions in various countries conserving Oriental cabbage germplasm. Genetic diversity and conservation requirements for the Oriental cabbages were described by Anonymous (1981). The largest germplasm collection is at the Asian Vegetable Research and Development Center in Taiwan. Much germplasm is being lost with the replacement of landraces by newly developed cultivars (Hamers 1989). Malo and Bourque (1992) described recent cultivar trials on subsp. pekinensis in Montreal. Facciola (1990) provided an extensive description of Oriental cabbage cultivars available in the United States. Yoon (1988) furnished a directory of worldwide researchers working on Chinese cabbage cultivars.


The seeds of Chinese mustard are said to have been ground for mustard in Europe (Hedrick 1972).

Problems and potential The Oriental cabbages are subject to various disease and pest organisms (Hamers 1989; Nonnecke 1989). A rotation period of 3 or 4 years without any Brassica crops is recommended. The Oriental cabbages are minor vegetables in Canada. As already noted, there is room for increased production to reduce imports. Demand for these vegetables is increasing as Canadians become more familiar with them.

Selected references Halpin 1978; Harrington 1978; Tindall 1983; Hamers 1989; Nonnecke 1989.

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Turnip

Names Scientific (Latin) name: Brassica rapa L. subsp. rapa Frequent scientific synonym: Brassica campestris subsp. rapifera (Metzg.) Sinsk. [Rapifera group (Bailey and Bailey 1976)] English common name: turnip Also: rapini, rappini, summer turnip French common name: navet (m) To avoid: rabiole (Boivin 1992)

Description and taxonomy Turnip is known only in cultivation. Leaves of this biennial develop the first year in the form of a rosette. Two types of crops are derived from turnip. The turnip “root” is made up of the main true root and the hypocotyl (the portion between root and stem tissue). It differs from the “root” of rutabaga (B. napus subsp. rapifera Metzg.), which also includes a short neck of stem tissue at the top. The turnip is generally smaller than the rutabaga. Most cultivars of turnip have white-fleshed roots, although some are yellow-fleshed. Most turnips are globe-shaped, although some are flat-topped. The “greens” or leaves of turnips are also collected as a vegetable and some cultivars have been selected specifically for the quality of these greens (Nonnecke 1989). Turnip was likely selected from biennial forms of Brassica rapa subsp. oleifera in the cooler parts of Europe. There are old Anglo-Saxon, Welsh, and Slavic names for the crop. Turnips were known to the ancient Romans in northern France and were likely introduced by them to Britain. The so-called stubble-turnip, selected for its rapid growth from late sowing, probably originated in 15th- or 16th-century Europe. These turnips were an autumn crop that was usually grown in rye stubble (Simmonds 1976). Jacques Cartier brought turnips to North America in A.D. 1540 and they were grown in the Virginia Colony in 1609. By 1800 they were cultivated by both native Americans and colonial Europeans (Nonnecke 1989). Some Canadian garden catalogs offer forms of Brassica under such names as “rapini,” “broccoli raab,” “spring raab,” and the cultivar name Rapine. These names are likely not being correctly applied. The name “rapini” or “rappini” designates cultivars of B. rapa subsp. rapa, turnip. “Rapini” has been selected for its edible greens. The name “spring raab” or “broccoli raab” applies to cultivars of B. ruvo Bailey, which are fast-growing annuals that form loose flowering heads in the axils of the lower leaves. Both the flower heads and the leaves are eaten. Based on Canadian catalog descriptions, it


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appears that the rapini and other such offerings are most likely B. ruvo, which is discussed under broccoli (B. oleracea var. italica).

Uses The roots are a well-known cooked vegetable, while the leaves are less commonly consumed as greens. Example recipes

Braised duck with turnips (Morash 1982) Dilled gratin of turnip and carrot (Morash 1982) Ginger-glazed carrots and turnips (Levy 1987) Indian pakoras (Tudge 1980) Old-fashioned scalloped turnips (Morash 1982) Pickled turnips with beets and fennel (Tudge 1980) Rapini frittata (Richardson 1990) Rapini quiche (Richardson 1990) Spring garden soup (Morash 1982) Turnip and onion gratin with parmesan (Levy 1987) Turnip greens and spinach in coconut-peanut sauce (Schneider 1986)

Importance There are very few statistics available for Canadian production of turnip roots. Turnip production statistics are often amalgamated with information for rutabagas (B. napus subsp. rapifera), for example, in Statistics Canada (1993b). In 1991, 554 t of domestic and 2517 t of imported turnips were unloaded at 10 major Canadian markets (Anonymous 1992a); in 1992, 607 t of domestic turnips were unloaded in these markets (Anonymous 1993a). Turnip is an important root crop in Europe with about 400 000 t grown annually (Hinton 1991). Rappini (or rapini) cultivars selected for their edible leaves may also be used in Canada. The extent to which the statistics listed for “rappini” apply to broccoli raab (Brassica ruvo) is uncertain because of different uses of the name rappini (see “Description and taxonomy”). Therefore, it is unclear to what extent the following statistics apply to broccoli raab (found under B. oleracea var. italica). In 1991, 162 t of domestic and 3278 t of imported rappini were unloaded at 10 major Canadian markets (Anonymous 1992a); in 1992, 134 t of domestic rapini were unloaded in these markets (Anonymous 1993a). Rappini has been one of the vegetables whose use expanded most dramatically during the 1980s in Toronto.


Turnips require deep, friable, fertile soil. Heavy soils will cause the root crop to become deformed whereas sandy soils require frequent

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irrigation. The roots penetrate deeply into the soil so that deep cultivation is essential. The pH should be between 6.0–7.5. Climate

Turnips are a cool-season plant with a relatively short growing period. For optimum seed germination and growth, mean air and soil temperatures should be 15–20°C (Anonymous 1988a; Nonnecke 1989).


Turnip is propagated by seed. The seeds germinate more readily than those of rutabaga. Uniform seed size will improve the consistency of the root crop. Commercial turnips are usually mechanically precision-seeded. They are sometimes grown indoors and transplanted for extra-early crops. Turnips mature about 2 weeks earlier than rutabagas (Anonymous 1988a).

Harvest and storage

The crop is marketed as bunched or topped summer turnips, or as turnip greens. Bunched turnips are tied and marketed with leaves at least 15 cm long. The leaves of topped turnips are trimmed to less than 2 cm. Turnip greens consist of either the entire plant or just the cut leaves. Most commercial growers mechanically harvest both turnip greens and roots. When harvested for bunching, the roots should be 5 cm in diameter, and for topping, 7.5 cm in diameter. Turnips with tops are washed and tied into bunches. Topped turnips are washed to remove any loose soil. Turnips for bunching are placed in crushed ice and will store for up to 2 weeks. Topped turnips are packed and top-iced in film, mesh, or cardboard containers (Nonnecke 1989).

Example cultivars

Turnip roots: Golden Ball, Purple Top White Globe, Royal Crown, Tokyo Cross, White Lady. (Many of these cultivars are also said to have delicious greens.) Turnip greens: Shogoin, Topper. The cultivar Green Tyfon, grown for greens, is said to be a Dutch introduction that is a cross between turnip and “Chinese mustard,” perhaps B. rapa subsp. chinensis, or “Chinese cabbage,” B. rapa subsp. pekinensis. Malo and Bourque (1992) described turnip cultivar trials in Montreal. Bettencourt and Konopka (1990) listed institutions in various countries that conserve turnip germplasm. Anonymous (1981) described genetic diversity and conservation requirements for turnip. Facciola (1990) provided an extensive description of turnip cultivars available in the United States.


In the time of King Henry VIII (1509–1547), turnips were used baked or roasted in ashes; the young shoots were used as a salad and as a spinach (Hedrick 1972).


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About 1850 in California, a turnip weighing about 100 lb (45 kg) was recorded (Hedrick 1972). The turnip Purpletop produces twice as much dry matter as winter wheat for forage and has attracted the interest of sheep farmers because it has proven to be desirable to sheep (Hart 1992). A fuel (rape methyl ester) derived from oilseed rape (B. rapa subsp. oleifera), a close relative of turnip rape, is increasing in popularity in Europe for buses, taxis, and tractors (McDiarmid 1992). Although slightly more expensive than diesel, it has been reported to produce almost no sulphur dioxide and less carbon dioxide.

Problems and potential Turnips are susceptible to various disease and pest organisms. They should be grown in crop rotation, free of other Brassica crops, on a cycle of 3–4 years (Anonymous 1988a). Both turnip and rappini are minor crops in Canada. There is potential for increase of both crops because domestic production meets only a portion of demand. Rappini, grown for greens, may be suitable for greenhouse or hydroponic production.


Campanula Rampion Campanulaceae Bellflower family Campanulacées, famille de la campanule

Genus notes Campanula comprises some 300 species of annual, biennial, or perennial herbaceous plants found in the northern temperate areas. Numerous species and garden hybrids are used as ornamentals (Huxley et al. 1992). Three species have been used as vegetables and potherbs. Two that are no longer grown for eating are C. persicifolia L., willow bell or peach bells, found in Europe, northern Africa, and northern and western Asia; and C. rapunculoides L., creeping bellflower, native to Europe. One species, discussed below, is still occasionally used as a vegetable.

Names Scientific (Latin) name: Campanula rapunculus L. English common name: rampion Also: ramps French common name: raiponce (f) Also: rampon

Description and taxonomy Rampion is a biennial herbaceous plant native to Europe, northern Africa, and western Siberia (Huxley et al. 1992). Cultivated and wild plants are indistinguishable. Rampion was grown in gardens for its edible roots and leaves in parts of Europe from the 15th to the 19th century (Organ 1960). By 1806 it was found in American gardens. However, it is now seldom raised as a vegetable because other root crops (such as carrots and parsnips) and leaf crops (such as spinach and lettuce) have increased dramatically in popularity, and rampion has been unable to compete with them.

Uses Rampion leaves can be collected during the summer and autumn and eaten like spinach. The white, crisp roots are excavated in the autumn and are washed and boiled like parsnips until tender. The cooked

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roots have a sweetish, some say walnutlike flavor (Hedrick 1972), although others find the taste disagreeable (Stephens 1978). Smaller roots can be cleaned and eaten raw with vinegar in salads. Blanched shoots are cooked like asparagus (Organ 1960; Grieve 1978). Example recipe

Rampion in cheese sauce (Organ 1960)

Importance No statistics seem available on rampion, which reflects its limited usage. It is still occasionally grown in parts of Europe, Asia, and Africa (Stephens 1978). It is also available in North America from a few seed companies.


Rampion performs best in a light, deep soil. The plants tend to flower in poor soils, which results in inferior roots (Organ 1960; Grieve 1978).

Climate

Rampion requires good moisture availability throughout the growing season. It performs well in full sunlight or light shade (Organ 1960). Although a biennial, during very hot weather rampion produces flowers and sets seed in the first year of growth (Stephens 1978).


Propagation is by seeds sown after danger of frost. The seeds are tiny, perhaps the smallest of all vegetable garden seeds (a gram contains 25 000). In spite of this they may remain viable for 5 years. The seeds can be mixed with fine sand to facilitate sowing, which is accomplished by pressing the mixture into the ground. The first few waterings should be provided carefully so as not to wash away the seeds (Vilmorin-Andrieux 1885). The young seedlings are thinned to 8–10 cm spacing in rows recommended to be 20 cm apart (Organ 1960; Stephens 1978). Occasional weeding is beneficial during the growing season.

Harvest and storage

A few leaves can be taken during the growing season for use as a cooked vegetable. Care should be exercised not to overpick the leaves as this may retard root growth. A few weeks before autumn, earth should be hilled around the lower stems to blanch them. The roots can be lifted in the autumn before a hard frost and can be used immediately or kept in damp sand in a cool place (Organ 1960). The roots will also store under refrigeration. Roots can be placed in a box and covered with a few centimetres of damp sand for forcing of new shoots. These blanched shoots are collected once they emerge from the sand.

Cultivars

Cultivars are not available, although rampion seeds can be obtained from some Canadian garden catalogs.

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The heroine of one of Grimm’s fairy tales, Rapunzel, is named after rampion, and the entire plot is woven around the theft of rampions from a magician’s garden (Grieve 1978). In an old Calabrian tale, a maiden uproots a rampion and discovers a staircase leading to a palace far below ground (Grieve 1978). There is an Italian tradition that the possession of a rampion causes quarrels among children. A decoction of rampion was once regarded as good for all inflammations of the mouth and throat (Grieve 1978).

Problems and potential Rampion is a little known and seldom grown plant that will likely remain a garden curiosity in Canada. It has no apparent commercial potential in Canada.

Selected references Organ 1960; Grieve 1978.

Capsicum Pepper Solanaceae Potato family Solanacées, famille de la pomme de terre

Genus notes Capsicum contains about 20 species, mostly perennial shrubs native to tropical America. In addition to C. annuum discussed below, four other species are grown. Capsicum baccatum L. is raised in South America, but only to a limited extent in the United States. Capsicum chinense Jacq. is grown mostly in tropical parts of the Americas, but one cultivar is now available in Canada as a spice pepper. Capsicum frutescens L., cultivated in tropical America and the southern United States, includes the “tabasco” peppers. Capsicum pubescens R. & P. is grown in the tropics from Mexico to Argentina and in southern California but has no potential in temperate climates (Heiser and Pickersgill 1969; Smith et al. 1987). The name “pepper” is applied to the fruits of Capsicum, both those used as a vegetable and those used as a spice. It should not be confused with the commonly used spice also known as “pepper,” obtained from berries of Piper nigrum L. This vine, native to India, requires a wet tropical climate and is grown chiefly in southern Asia. The Old World name pepper was adopted for the New World Capsicum after the latter was brought back to Europe and proved to be an equally attractive spice.

Names Scientific (Latin) name: Capsicum annuum L. Common English name: pepper (Additional names below) Common French name: poivron (m) Also: piment, piment doux Bell pepper

Description and taxonomy The cultivated form of the species has been designated var. annuum (Andrews 1984). This plant is a herbaceous annual in temperate regions but may become a woody biennial in warmer climates. It is the most widely used pepper in the world and includes green (or bell

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peppers), cayenne, pimento, and pungent chile peppers. A variety of fruit types and degrees of pungency have been selected. There are far more cultivars of C. annuum than of all the remaining species of Capsicum combined. A modern horticultural classification of peppers grown as vegetables in the United States (Smith et al. 1987) includes the following forms, most if not all encountered in Canada (new F1 hybrids do not fall clearly into these groups): Bell group. These forms have large, smooth, thick-fleshed, mostly nonpungent fruits; they include the common green and red peppers, and are used in salads, soups, and processed meats. Cherry group. This group has globular, nonpungent, thick-fleshed fruits that are used for salads and pickling. Cuban group. The variably yellowish green, thin-walled, fruits of this group are pickled. Long wax group. The fruits of pungent and nonpungent types of this group are greater than 8.8 cm long and are used Cherry pepper fresh, pickled, and in sauces and relishes. A more extensive discussion of those peppers used as spices and flavoring (including cultivars of C. annuum and C. chinense) appears in Culinary Herbs (Small 1997). That volume includes descriptions of chile and paprika peppers. The sweet vegetable peppers described in this chapter have insignificant or no capsaicin, the pungent chemical that makes all of the spice peppers spicy. The fruits of peppers are highly perishable so, not surprisingly, ancient remains have not been discovered. Archeologists have found embroidery depicting Capsicum from A.D. 400, and carvings from A.D. 800 in the Americas. Columbus is thought to have brought the pepper back as a spice on his first voyage. Once in Europe it quickly spread as a substitute for black pepper. Later, some of the milder forms were selected. This pepper was eventually reintroduced to the New World with European colonization (Nonnecke 1989). The wild C. annuum var. minimum (Miller) Heiser (Heiser and Pickersgill 1969), commonly called the bird pepper, is considered as a possible progenitor of the domesticated plant. This herb or small shrub grows to 2 m tall. It is found in the southern United States south to northern Peru and is widespread in the Caribbean (Andrews 1984).

Uses Peppers are used as vegetables and as condiments. Large, thick-fleshed sweet varieties are widely incorporated into salads and are stuffed with meat and then cooked. Immature fruits of bell

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peppers are often picked while still green for these purposes. Sweet and hot peppers are often pickled, and an increasing volume is being frozen for use in pizzas and other foods. Example recipes

Chicken with peppers (Morash 1982) Cold pepper and zucchini salad (Morash 1982) Corn salad with peppers (Levy 1987) Crêpes with peppers, onions, and peas in curry sauce (Levy 1987) Marinated pepper salad (Richardson 1990) Multicolored pilaf with sweet red peppers and walnuts (Levy 1987) Peeled peppers in oil (Morash 1982) Pepper pasta salad (Richardson 1990) Pepper and cheese bake (Morash 1982) Pipérade (omelette) (Morash 1982) Potato-pepper salad à la Provençale (Levy 1987) Roasted pepper canapés (Levy 1987) Stuffed red pepper with Spanish rice and tomatillo sauce (Ornish 1990)

Importance Peppers are a major crop worldwide and have been described as one of the most important tropically grown vegetables. Annual world production of peppers often exceeds 6 000 000 t (Andrews 1984). Annual Canadian production is of the order of 20 000 t, worth about $10 000 000 (Dubé et al. 1990). Of all peppers used in Canada (for both processing and fresh consumption) about 30% are produced domestically (Coleman et al. 1991). Cultivars of C. annuum can be raised in parts of all provinces, provided that they are started indoors. Much of the commercial production of pepper in Canada is in the extreme southern regions along the shore of Lake Erie, where a considerable amount is grown for the fresh and processing markets. Ontario is the principal producer in Canada, followed by Quebec and British Columbia.


Soil should be well-drained and friable, with a pH of 6.5–7.5. Abundant organic matter is recommended for adequate fertility and water-holding capacity. Peppers respond well to frequent side dressings of supplemental nitrogen.

Climate

In Canada, peppers are started indoors and transplanted outdoors once the soil is warm. They are intolerant of cold weather. Peppers grow best at temperatures of 21–29.5°C, with a low of 18°C and high of 35°C for limits of tolerance. For proper germination, soil temperatures must be above 16°C. Desirable fruit color depends on soil temperature, with best appearance developing between 18–24°C and no color formation below 13°C. Smaller-fruited types of peppers are less sensitive to cold than large-fruited types such as the bell peppers.

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Peppers must be provided with a steady supply of water throughout the growing season, necessitating irrigation during dry spells. Propagation and cultivation

Peppers are propagated by seed sown indoors and transplanted outside once the soil is warm. In commercial operations they are best planted in individual plastic trays, thus reducing root damage. Light cultivation is practical and useful for weed control until the plants begin to spread out (Nonnecke 1989). Trials conducted at the Kentville Research Station of Agriculture and Agri-Food Canada in Nova Scotia found that growing peppers in unventilated “plastic tunnels” (semi-circular, about 1 m high, the length of the row) tripled the crop (Johnson 1992b).

Harvest and storage

The large table peppers, such as bell peppers, are hand-harvested because they are easily bruised or broken. Peppers will renew fruit formation after a harvest so that repeated harvesting is usual. Fruits destined for dehydration or freezing are machine-harvested after the fruits have mature coloration. Peppers are sensitive to chilling injury and must not be held at temperatures below 7°C. Optimum temperatures are 8–9°C. The fruit should be hydrocooled after picking but should be dried quickly to prevent decay. Fully ripe peppers can be stored for a week. Bell peppers (green, red, yellow, etc.): California Wonder, Camelion, Early Prolific, Gypsy, Hungarian Sweet, Purple Beauty. F1 hybrids: Bell Boy, Big Bertha, North Star. Cherry group (nonpungent cultivars): Cherry Sweet, Super Sweet Cherry. Cuban group: Cubanelle. Long wax group (nonpungent cultivars): Early Sweet Banana, Giant Yellow Banana, Sweet Hungarian. Trials of pepper cultivars in Montreal were discussed by Malo and Bourque (1992). Pepper Various cultivars breeding was presented in depth by Greenleaf (1986). The international standards of quality and marketing of peppers were described by Anonymous (1982). Bettencourt and Konopka (1990) listed institutions in various countries conserving Capsicum germplasm. Facciola (1990) provided an extensive description of pepper classes and cultivars available in the United States.

Example cultivars

Additional notes Peppers such as bell peppers, can be nonpungent, others very pungent, such as tabasco peppers. The compound responsible for the spicy, hot taste is a crystallin nitrogenous chemical called capsaicin. A drop containing one part in 100 000 causes persistent burning of the tongue and one part in 1 000 000 gives a warm sensation, even though

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capsaicin is without odor or flavor. In 1912, a test was devised to measure peppers in so-called Scoville heat units. Bell peppers are rated at 0, Anaheim at 1000, jalapeño and cayenne between 2 000 and 25 000, and tabasco (C. fructescens L.) between 60 000 and 80 000. The degree of pungency is enhanced by warm nights, hot days, poor soil, well-aged fruit and thin pod skin (Nonnecke 1989). Police now commonly use capsaicin sprays on rowdy or dangerous suspects. The spray generally incapacitates the suspect for 2–3 min, sufficient time to apprehend the person. In 104 cases, the spray was 93% successful as “totally effective for use to incapacitate a suspect” (Park 1992). Curiosities

The active principle in pungent peppers, capsaicin, is capable of remarkable levels of irritation. According to Parry (1945) “The small African[-grown] chillies, when disturbed, give off an offensive, irritating, acrid dust and should be handled with care. Do not put fingers to the eyes after handling chillies and do not taste the chillies if you would like to avoid painful, smarting eyes and mouth. This applies also to the large-fruited varities of pungent red peppers.” Hot varieties of pepper are well known for causing irritation to the hands of pickers. Capsicum has produced burns requiring medical attention and has reputedly been used for torture. Peppers are employed to a minor extent in medicine, having found considerable use in the past. Highly pungent preparations have been used as a counterirritant for rheumatism and neuritis, as a gargle for certain throat inflammations, and internally for alcoholic gastritis and certain kinds of diarrhea. Pepper poultices were once popular and are still sometimes used. The use of a topical analgesic cream made with capsaicin is mentioned in the article “Adios, arthritis pain” by V. Fahey, published by Walking Inc., Boston, Mass., in Walking Magazine Jan./Feb. 1993.

Problems and potential As already noted, domestically grown peppers represent about 30% of the total market for peppers in Canada. However, with the short growing season, intolerance of peppers to cool weather, and short storage life of fresh peppers, it is unlikely that domestic production will be able to compete with off-season foreign imports. Peppers can be grown as a greenhouse crop, particularily the new vigorous F1 hybrids, to provide a fresh crop outside the regular Canadian growing season. Over 15 ha of sweet bell peppers were grown in greenhouses in 1991 (Amor 1992).

Selected references Heiser and Pickersgill 1969; Andrews 1984; Smith et al. 1987; Small 1997.

Chenopodium Good King Henry Chenopodiaceae Goosefoot family Chénopodiacées, famille du chou gras

Genus notes Chenopodium comprises about 250 annual and perennial species of wide distribution (Bailey and Bailey 1976). In addition to C. bonus-henricus, a potherb that is discussed below, several other species are grown as ornamentals, for their nutritious seeds, and as potherbs. These others include the following: Chenopodium album L. (lamb’s quarters), which originated in Eurasia, is now an annual weed worldwide. It is sometimes collected from the wild as a potherb. Chenopodium ambrosioides L. (Mexican tea or wormseed) is an annual or a perennial depending on its situation. This plant is native to tropical America and is cultivated for its essential oil, which has medicinal properties. A detailed account of its use as a culinary herb is given in Small (1997). Chenopodium botrys L. (Jerusalem oak) is native to Eurasia and northern Africa and is now naturalized in parts of North America. This annual is sold as an ornamental, particularly for its dried flowers. A detailed account of its use as a culinary herb is given in Small (1997). Chenopodium capitatum (L.) Asch. (strawberry blight) is an often weedy annual, native to North America, which also occurs in Eurasia. It is sometimes collected from the wild for use as a potherb. Chenopodium quinoa Will. (quinoa) is native to the Andes, and the seeds are a staple grain in parts of South America. The newly formed Canadian Quinoa Association anticipated growing about 400 ha of quinoa annually (Anonymous 1992e). Health-food stores in Canada sold about 60 000 kg of quinoa in 1991 (Anonymous 1992g).

Names Scientific (Latin) name: Chenopodium bonus-henricus L. English common name: good King Henry Also: good-King-Henry, good-Henry, mercury, allgood, fat-hen, goosefoot, wild spinach French common name: ansérine Bon-Henri (f) Also: arroche Bon-Henri, épinard sauvage

Chenopodium (good King Henry)

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Description and taxonomy The cultivated form is indistinguishable from the wild plants. The wild form is a perennial herbaceous plant native to Eurasia. In North America it has been introduced and naturalized along roadsides, in waste places, and on cultivated ground. In Canada it has been found in British Columbia, Ontario, southwestern Quebec, and the Maritime Provinces (Scoggan 1978–1979). Good King Henry was once widely cultivated in European and colonial American gardens and is now flourishing in the wild on both continents. It was mentioned as a wild plant in 1597, and as a vegetable in 1686 in England. In 1807 it was widely cultivated in Lincolnshire, England, where it was preferred over spinach (Hedrick 1972). With the perfection of beet, Swiss chard, and spinach, good King Henry lost favor and today is rarely cultivated in European gardens. It is almost unknown in North America (Halpin 1978).

Uses The young leaves and shoots are edible and are cooked for use like other greens. The young shoots are collected in the spring and, after cleaning, are cooked like asparagus, which they resemble in flavor. The outer skin should be removed first from older stems. The leaves are lightly steamed, as with spinach (Halpin 1978). Example recipes

Creamed good King Henry (Halpin 1978) Good King Henry stalks in Hollandaise sauce (Halpin 1978)

Importance Good King Henry is now seldom grown. However, it is occasionally found in home gardens in Canada.


Good King Henry will grow on a wide variety of substrates but does best on a rich, well-drained soil.

Climate

This plant has successfully naturalized through much of southern Canada and will overwinter in these locations. Irrigation is beneficial during dry periods (Halpin 1978).


Propagation is by seeds, which are sown as early as possible in the spring. The seeds can also be started indoors, and they transplant easily in the spring. This vegetable can also be propagated by root division.

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Some gardeners suggest that the plants be allowed to establish the first year, after which both the shoots and leaves are harvested. The bed should be kept moist and free of weeds. Once established, this hardy perennial will continue to grow and self-sow for years, although it is recommended that a new crop be started after 10 years. New seedlings should be removed wherever plants are not desirable (Grieve 1978; Halpin 1978). Harvest and storage

Good King Henry leaves may be collected throughout the growing season, although they are best during the spring and early summer. The young shoots can also be harvested in the early spring. If the overwintering plants are covered with a heavy mulch, they are usually the first fresh green vegetables available each year. Young stalks need no preparation other than cleaning. Older leaves become bitter, and the plant is considered inedible once it has gone to seed (Halpin 1978).

Example cultivars

Cultivars are unavailable. This plant is sold in Canadian garden catalogs as “good King Henry.”


Good King Henry was favorably regarded widely for its medicinal properties; hence the common names Mercury goosefoot and wild Mercury, in honor of the ancient Roman god of medicine (Halpin 1978). Good King Henry is sometimes called fat-hen, a reference to the medieval use of the older leaves for fattening poultry. The plant’s supposed versatility led to another name, all-good, and may have produced the most familiar name, good King Henry, which refers to the much-loved English king, King Henry VII. An alternate explanation is that the name comes from the German “Heinz” and “Heinrich,” for elves and kobolds, indicating magical powers. The roots were given to sheep as a remedy for cough (Grieve 1978).

Problems and potential Good King Henry has little potential as a commercial vegetable, but it is a hardy perennial plant that provides an early crop of edible leaves and shoots for the home gardener.

Selected references Grieve 1978; Halpin 1978.

Chrysanthemum Chop suey green Compositae (Asteraceae) Sunflower family Composées, famille de la marguerite

Genus notes The genus Chrysanthemum has been considered to have about 200 species (Bailey and Bailey 1976), but recent taxonomic work has resulted in the segregation of most of these into other genera, so that now only three annual species remain (Soreng and Cope 1991). Two species are cultivated as ornamentals and one, used as a vegetable, is discussed here.

Names Scientific (Latin) name: Chrysanthemum coronarium L. English common name: chop suey green Also: garland chrysanthemum, crown daisy French common name: chrysanthème des jardins (m) Also: chopsuy (chopsouy, chop soui) vert [last term from Organ 1960]

Description and taxonomy Chop suey green, also often called crown-daisy, is an annual herbaceous plant grown for its edible leaves. It is known as “shungiku” or “shiyungiki” in Japan, “tanghoe” in China, and “fior d’oro” in Italy (Schultze-Motel 1986, Soreng and Cope 1991). In North America the name chop suey green is most commonly used. Edible C. coronarium has fleshier leaves than the form cultivated as an ornamental, with a large terminal lobe and much smaller lobes near the base. It is sometimes considered to be a distinct species and was listed as C. spatiosum by Nicholson et al. (1975). Three kinds of edible C. coronarium have been recognized according to leaf size (Yamaguchi 1983), as follows: finely parted, narrow, dark green leaves (both Rosette of edible cultivar cold and heat tolerant)

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intermediate leaf size (both cold and heat tolerant) broad, somewhat clefted, pale green leaves (adapted to warm regions) Chrysanthemum coronarium is native to the Mediterranean and southwestern Europe (Clapham et al. 1987). It has been found as an occasional garden escape in Canada, in southern Ontario and New Brunswick (Scoggan 1978–1979).

Uses Chop suey green is most commonly employed in Canada as an ornamental in beds and flower garden borders. It is used for its edible leaves in China, Japan, and Taiwan, generally in combination with other foods. The flavor may seem rather strong to those unaccustomed to it. In Japan the flower heads are also eaten, although there is disagreement about the advisability of this; Nakao (1976) wrote that “they are too stinky.” Harrington (1978) recommended that flowers should be dipped in boiling, salted water before serving, and that dried petals should be soaked in water before Inflorescence of flowering cultivar adding to other ingredients. Petals of chop suey green are a component of a distinctive Japanese pickle called kikumi. The tender shoots are used in stir-fries or steamed and are added to flavor soups, meat, and fish dishes (Halpin 1978). The leaves are cooked briefly in a small amount of water, like spinach. The leaves have a characteristic odor of chrysanthemums. This vegetable is best combined with other greens or vegetables (Harrington 1978). Example recipes

Garland chrysanthemum salad (Buishand et al. 1986) Red cabbage with apples and chrysanthemums (Leggatt 1987)

Importance No statistics seem available on production or use of chop suey green. It is used mainly in Japan, in many dishes. In Canada, C. coronarium grown as a vegetable is a curiosity of home gardens.


Chop suey green grows best in well-drained loam soil rich in organic matter (Harrington 1978).

Climate

This cool-season plant is grown in the spring or early autumn. It can be started indoors and transplanted in mid spring for an early crop.

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The plants require constant soil moisture. Chop suey green will tolerate partial shade (Halpin 1978; Harrington 1978). Propagation and cultivation

Propagation is by seeds, which can be sown as early in the spring as the soil can be worked. Alternatively, transplants can be used for early crops. Successive plantings are recommended until late spring. Hot temperatures result in bitter-tasting leaves. Seeds can be sown in late summer for an early autumn crop. Occasional weeding may be required (Harrington 1978).

Harvest and storage

The leaves are hand-picked 6–7 weeks after sowing, when about 12–15 cm long. The entire plant can be harvested, or the tender side leaves can be cut at ground level. If not uprooted, chop suey green will regrow. Flower buds are pinched off to promote the development of young leaves. The leaves should be consumed fresh but can be stored for a short time in a refrigerator. Many home gardeners will allow a few plants to flower as an ornamental and to produce seed. The plant grows 60–100 cm tall and has attractive flowers. Mature seeds can be collected and used for replanting (Halpin 1978; Harrington 1978).

Example cultivars

Cultivars of this plant do not seem to be available. It is sold in Canadian garden catalogs under the names “shungiku” and “chop suey green.”


The high regard in which chop suey green is held in Japan is reflected by its presence as an ingredient in a special dish served as part of the tea ceremony. The Japanese custom of dipping flowers in saki to begin a meal is reputed to give health and long life (Harrington 1978). Chop suey green, the national flower of Japan, was regarded as an important herbal plant in that country. It was a chief ingredient in a formula for promoting longevity, returning gray hair to its original color and replacing lost teeth, so that “an old man of 80 would become like a boy again” (Harrington 1978). In China, chop suey green represents a life of ease and joviality and is particularly appreciated by older adults as a symbol of mature beauty (Harrington 1978).

Problems and potential This vegetable will likely remain a novelty of home gardens. It may be used occasionally in Japanese-style restaurants, and so may have a very limited potential commercial market.

Selected references Halpin 1978; Harrington 1978.

Cichorium Compositae (Asteraceae) Sunflower family Composées, famille de la marguerite

Genus notes The genus Cichorium is composed of nine species native to the Mediterranean region, one of these reaching northern Europe and another Ethiopia. Two of the species have been domesticated (Clapham et al. 1987) and are dealt with below.

Endive

Names Scientific (Latin) name: Cichorium endivia L. English common name: endive Also: escarole French common name: scarole (f) Also: chicorée scarole, chicorée endive [To avoid: escarole (Boivin 1992). Chicorée endive (from Organ 1960) is international. Scarole and chicorée scarole are accepted in Quebec. The French word endive designates C. intybus (sometimes called French endive) discussed later. By contrast, the English word endive designates C. endivia.]

Description and taxonomy Both wild and cultivated plants of C. endivia are known. The cultigen is separated as subsp. endivia by some authors (Clapham et al. 1987) and has been divided further to reflect the two forms, endive and escarole (Hedrick 1972; Schultze-Motel 1986; Nonnecke 1989). Endive (var. crispum Lam. of some authors [Schultze-Motel 1986]) has Endive leaves that are heavily curled and deeply toothed; the leaves of escarole (var. latifolium Lam. of some authors [Schultze-Motel 1986]) are broader and slightly crumpled. Escarole is probably the more ancient form, although endive is also a very old vegetable, used in ancient Egypt and India. It may have originated in either region and was also used in ancient Greece as a salad and

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potherb (Hedrick 1972). In this treatment, the name “endive” is usually used to denote both forms, and “escarole” is used specifically for the form with uncurled leaves with an entire margin (the edge not incised or segmented). Endive was noted in North American literature as early as 1806 and has been grown extensively in gardens since then. This annual or biennial herbaceous plant Escarole produces a shortened stem with a rosette of leaves. Endive has been reported as a garden escape in Canada but has probably not become established (Scoggan 1978–1979). The wild form, subsp. divaricatum (Schousboe) P.D. Sell (var. endivia of authors such as Schultze-Motel (1986), is a low-growing herb with hairy basal leaves, found in the Mediterranean region (Clapham et al. 1987).

Uses Endive leaves are used raw as an addition to salads and cold vegetable dishes (Nonnecke 1989). Example recipes

Chicory (endive) Tian (Morash 1982) Escarole salad with roquefort cheese (Levy 1987) Escarole soup (Morash 1982)

Importance Endive is far more important to Europeans than to North Americans, who generally prefer lettuce in salads. For example, in 1988, what was then West Germany imported 40 085 t of endive (Hinton 1991). As well as being cultivated in Europe, endive is grown commercially in Egypt, Iran, North India, China, Japan, South Africa, Brazil, and the Caribbean. Endive is produced as a winter vegetable in Florida and as an annual summer vegetable in more northern areas of North America. In 1990 only 2410 t of endive and escarole were used in Canada of which only 716 t (372 t of endive and 344 t of escarole) were produced domestically (Anonymous 1991b). In 1992, 267 t of domestic escarole were unloaded in 10 major Canadian markets (Anonymous 1993a). In Canada, the main production areas are Ontario and Quebec.

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Endive will grow on a wide range of substrate types, from mineral to muck soils. The pH can range from 6.0 to 7.5. Maximum production demands good fertility and, on muck soils, a side-dressing of nitrogen may be beneficial during midseason.

Climate

Endive is classed as half-hardy and can grow where winters are mild. Cool summers are preferable Endive with optimum conditions ranging from 15–18°C and maximum temperature only 24°C. Endive ceases growth if subjected to warmer conditions. It will bolt in hot weather, reducing leaf growth (Nonnecke 1989).


Endive is usually direct-seeded, but some growers, to gain price advantage on the early market, may achieve an early start on the season by using transplants. The most important cultural requirement is constant soil moisture (Nonnecke 1989). When sunlight is kept from the center leaves, their green color is reduced, bitterness is decreased, and texture and flavor are improved. Blanching for 2 to 3 weeks before harvest may be carried out by tying the tops of the outermost leaves together as the heads develop. The plants should be dry before tying or the inner leaves may rot. After the blanched heads have developed, the plants are cut at ground level. The tough outer leaves may be discarded.

Harvest and storage

Endive is ready to harvest 70–90 days after seeding. Harvesting is carried out by hand. Discolored leaves and defective hearts must be removed. Vacuum or hydrocooling are required to quickly reduce the respiration rate of the product immediately after harvest. Shelf life is 3 weeks at 0°C, but only half that time at 5°C (Nonnecke 1989).

Example cultivars

Endive: Green Curled, Salad King, Tosca. Escarole: Full Hearted Batavian. Bettencourt and Konopka (1990) listed institutions in various countries conserving C. endivia germplasm. Facciola (1990) provided an extensive description of endive cultivars available in the United States.


Fresh endive is 95% water.

Problems and potential As reported in Anonymous 1991b, only about 25% of the endive and escarole used in Canada in 1990 were produced domestically. Thus it is possible to expand the amount of endive grown in Canada.


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However, the short Canadian growing season and limited shelf life of the product means that domestic producers cannot supply endive for as long as foreign growers. On the positive side, endive rarely suffers significantly from pests and diseases.


Chicory

Names Scientific (Latin) name: Cichorium intybus L. English common names: chicory, radicchio (pronounced ra-dee-key-o) Also: Belgian endive, chioggia, French endive, Italian chicory, witloof chicory, witloof, radichetta, red chicory, red-leaved chicory, succory, blue sailors French common names: chicorée sauvage (f), radicchio (m) Also: chicorée rouge, endive, barbe-de-capucin, chicorée [Chicorée sauvage is applied either to roots or foliage of wild plants. Radicchio and chicorée rouge are applied to English terms radicchio, red chicory, and red-leaved chicory. Endive is applied to broad-leaved forms. Barbe-de-capucin is an international French term, applied to edible roots. Chicorée is an international term (Organ 1960) for any part of the plant.]

Description and taxonomy Chicory is a perennial herbaceous plant native to parts of Eurasia and Northern Africa (Clapham et al. 1987). Three groups of cultivars may be recognized. One distinctive group of cultivars (var. foliosum Hegi of some authors [Schultze-Motel 1986]) are forced, after a cold treatment, to produce the chicon (tightly closed rosette of leaves). These forms have smooth leaves and white midribs. They are dug in the fall, given a cold treatment, and forced in the dark to produce the chicons. They are variously called witloof chicory or French, Belgian, or Brussels endive. The remaining two groups of cultivars are sometimes placed in var. sativum Lam. et DC. of some authors (Schultze-Motel 1986). Nonforcing forms comprise one of

Chicon of forcing type

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these groups. They have crinkly or smooth leaves with either red or white midribs. The plants (some resembling head lettuce) are harvested 2–3 months after sowing. The green-leaved forms (Italian selections called radichetta) are grown for their deeply notched foliage and petioles that are used in salads. The broadleaved forms (Italian selections called radicchio, chioggia, or Italian chicory) are also grown for their Radicchio dark red or variegated red and green leaves, which are used in salads (Resentera 1980; Buishand et al. 1986; Hill 1989). The second group of cultivars placed in var. sativum are forms selected specifically for their distinctive, deep, fleshy tap roots, some growing more than 30 cm in length, that are used as a coffee substitute. In Italy this group of cultivars is sometimes called Cicoria Siciliana or Magdeburg (a name also given to a single cultivar). The roots of the other groups of cultivars are also sometimes dried and used like coffee (Resentera 1980; Nonnecke 1989). Extensive information on the use of chicory roots as coffee is given in Small (1997). The wild plant, var. intybus of some authors (Schultze-Motel 1986), has been introduced in the Americas, South Africa, Australia, and New Zealand. In Canada, chicory Magdebrug chicory grows, often abundantly, in waste places and fields and along roadsides. It is found from southern British Columbia to Nova Scotia (Scoggan 1978–1979). Although chicory may have been used earlier in Europe, it was not domesticated until 1845 at the Botanical Gardens in Brussels. That form became known as “witloof,” Flemish for “white leaf.” Cultivation was so successful that by 1875 roots were exported to France for consumption. By 1899, chicory production was a new enterprise in the United States (Nonnecke 1989). Many forms were selected in Italy for their edible salad leaves, including radicchio, which originated in the Veneto region (Hill 1989).

Uses The forcing forms of chicory are generally grown for the blanched shoots (chicons), which are cooked by steaming, boiling, or baking and used in vegetable dishes. Although the chicons may initially seem somewhat bitter to Canadians accustomed to lettuce, they are considered a delicacy in Belgium, Holland, and France. During the summer the dandelionlike leaves can be cooked or used in salads, and the roots may be cooked and eaten like carrots (Nonnecke 1989).


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The nonforcing forms (including raddichio and radichetta) are sown in late June through late July for autumn harvest. The leaves are used fresh in salads. Forms selected for edible roots are pulled, washed, and cut into pieces and then dried and roasted in a slow oven until coffee-brown. The Chicory (form used as coffee substitute) pieces are ground and mixed with a similar grind of coffee to make a pleasant drink. Chicory is added to some coffee brands marketed in Canada and is also available separately as a coffee substitute. The addition of chicory gives coffee a deeper color and longer-lasting flavor and aroma. The chicory found as a common weed in fields and along roadsides in parts of southern Canada can be used as a coffee substitute. The roots have been used extensively in Europe as a substitute for, or addititive to, coffee, especially during times when coffee was scarce or expensive. Wild chicory roots can be dug up during the summer months, washed, and cut into short segments. These segments are roasted in a slow oven at 120°C until they are brown and brittle. They are then ground and stored in a closed container in a cool place (Turner and Szczawinski 1978). The wild plants can also be dug up in late fall and stored in moist sand in a cool place, with occasional watering. Young crisp sprouts will appear a few weeks later. Because these are wild plants they may not be as acceptable as cultivars. The leaves of forms with roots selected as a coffee substitute can be picked and used in salads (Resentera 1980) but also may not be as palatable as cultivars selected for edible leaves. Chicory has been studied at the Agriculture and Agri-Food Canada Research Station at Delhi, Ont., for its yield potential of inulin. The inulin can be hydrolyzed to produce a high-fructose syrup that is used in the food and beverage industry. Example recipes

Belgian endive gratin with cream sauce and walnuts (Levy 1987) Braised endive (Organ 1960) Breast of veal with endive stuffing (Morash 1982) Chicory coffee (Szczawinski and Turner 1978) Chicory soufflé (Morash 1982) Endive and beet salad with champagne vinaigrette (Levy 1987) Endive and mandarin salad (Richardson 1990) Endive salad (Morash 1982) Endive, fennel, and red pepper appetizer (Morash 1982) Grilled red-leaved chicory (radicchio) (Buishand et al. 1986)

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Radiccio and smoked salmon hor d’oeuvre (Richardson 1990) Red-leaved chicory (radicchio) salad (Buishand et al. 1986) Sautéed radicchio, mushrooms, and fennel (Schneider 1986) Spaghetti with radicchio, anchovies, and garlic (Schneider 1986) Tantalizing chicory canapé (Szczawinski and Turner 1978)

Importance Chicory is far more important in Europe than in North America. In fact, the culture of Belgian endive employs, at least part time, some 300 000 workers in France alone (Whitney and Corey 1988). In Europe in 1987, 571 400 t of all types of chicory were grown on 45 800 ha, with the Netherlands producing 70 100 t on 4 800 ha (Hinton 1991). In Canada in 1990, a total of 2091 t of chicory was used with only 536 t grown domestically (Anonymous 1991b). In 1992, 410 t of domestic Belgian endive and 293 t of French endive were unloaded in 10 major Canadian markets (Anonymous 1993a). Canadian chicory is produced mainly in Quebec, less in Ontario, and a small amount in British Columbia. Canadian demand for radicchio in 1993 has been estimated (in constant 1988 dollars) as follows: 555 t valued at $2 489 000 dollars in Toronto, 200 t valued at $896 000 in Montreal, and 29 t valued at $129 000 in Vancouver (Anonymous 1989).


Chicory will grow on a wide range of soil types from mineral to muck soils. The pH can range from 6.0 to 7.5. Maximum production demands good fertility and, on muck soils, a side-dressing of nitrogen may be beneficial during midseason (Nonnecke 1989).

Climate

Cultivated chicory is a hardy perennial that may be grown in parts of all provinces. Commercial cultivars are either direct-seeded or transplanted after soils remain above 7°C. Sustained periods below this temperature cause bolting, which prevents the development of chicons (Hill 1985; Corey et al. 1990). Irrigation is advisable during dry periods.


Propagation is by seeds, usually precision-seeded (Nonnecke 1989). The nonforcing types may be started indoors and transplanted for the early market.

Harvest and storage

Roots of the forcing type of chicory must be lifted at the proper stage of development. Test roots can be split lengthwise to expose a cross section of the area just below the crown. The white patch just below the crown should be 0.5–1.0 cm thick. Roots with thinner patches will not produce tightly furled chicons; roots with thicker patches usually produce numerous crowns and unmarketable chicons (Hill 1989). The roots are undercut to about 20 cm, lifted and left on the surface of the soil to dry, after which the tops are trimmed to 5 cm. The roots are held in storage prior to forcing at 2°C and 95–98% humidity for


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105–130 days. The early, mid, and late-maturing types require increasing lengths of storage to produce vernalization (a cold period required for subsequent growth or maturation). Early types may only need 1 week of cold treatment, whereas late-maturing types may take 8 weeks. To force the roots, they may be either placed diagonally in soil, peat, or rockwool; or put under plastic with or without soil (Nonnecke 1989); or forced in nutrient solutions in special forcing units (Hill 1985; Whitney and Corey 1988; Sterrett and Savage 1989). In Europe, harvests of 450 000 chicons per hectare can be achieved (Whitney and Corey 1988). The chicon is highly perishable and must be cooled quickly to 0°C at 95% humidity, preferably in the absence of light to prevent greening. Its storage time is 2–4 weeks. For the home gardener, the transplanted roots can be buried under 2 cm of soil in boxes or flower pots in a cool, dark place. The crop can be snapped off when it reaches 12–15 cm tall. Three or more harvests are possible from each root (Resentera 1980). The nonforcing type of chicory can be harvested in as little as 60 days. These produce red and white or variegated heads of leaves (resembling head lettuce), which are cut and quickly cooled to reduce respiration (Hill 1989). The plants can also be moved into a cool greenhouse. Leaves become sweeter with cool temperatures and can be taken from the plants all winter (Resentera 1980). Example cultivars

Witloof chicory or Belgian endive: Brussels Witloof, Sugar Loaf French, Turbo Hybrid, Witloof Improved. Radichetta: Cicoria Catalongna. Radicchio: Adria. Coffee substitute: Magdeburgh (or Magdeburg, or Cicoria Siciliana). Bettencourt and Konopka (1990) listed institutions in various countries conserving C. intybus germplasm. Facciola (1990) provided an extensive description of chicory classes and cultivars available in the United States.

Additional notes Belgian researchers have inserted an antisense gene into chicory, a major source of fructans. Fructans are soluble forms of fiber and are used in a range of foods from pizza to mousse. A problem with chicory has been that, after harvest, plant enzymes rapidly break down the fructans to fructose as soon as the plant is picked. Such fast change has meant that the “lorries have to race to the factory from the field.” The antisense gene blocks the enzyme that performs the breakdown, preserving the desirable fructans (Anonymous 1992f). Because chicory is classed as a weed under federal Canadian legislation (Anonymous 1986c), importation of seeds into Canada could be problematical.

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Curiosities


A decoction of the roots was purported in the Middle Ages to be effective in treating jaundice, liver enlargements, gout, and rheumatic complaints (Grieve 1978). “Barbe de capucin” (literally “beard of the friar”) originated from the French notion that the epicurean heads of witloof chicory had a shape like a goatee (Kraft and Kraft 1978).

Problems and potential About 25% of chicory used in Canada is grown domestically, mostly in Quebec (Anonymous 1991b). The domestic production of chicory can be expanded (especially the witloof and radicchio forms). The witloof type is forced and can therefore be marketed at various times through the winter and spring. The radicchio type is a fresh vegetable that is marketable in season. Marketing problems include short shelf life and the need to develop a retail pack that excludes light and undesirable greening, yet allows consumers to view the product (Corey et al. 1990).

Selected references Resentera 1980; Hill 1985, 1989; Corey et al. 1990; Mitich 1993.

Crambe Sea kale Cruciferae (Brassicaceae) Mustard family Crucifères, famille de la moutarde

Genus notes Crambe consists of 20 species of herbaceous or shrubby plants native to Europe and western Asia. The genus includes annuals and perennials (Bailey and Bailey 1976). Crambe abyssinica Hochst. ex R.E. Fries (C. hispanica A. Rich.), crambe, is an oil plant that is attracting increasing interest. Its seeds contain 30–35% oil, which is nearly twice that of soybeans (Glycine max (L.) Merr.). Moreover, the oil has 8–9% more erucic acid than industrial rapeseed oil (derived from subspecies of Brassica rapa and B. napus [Cooke and Konstant 1991]). Crambe cordifolia Steven, colewort, is grown as an ornamental. Crambe maritima, used as a vegetable, is discussed here.

Names Scientific (Latin) name: Crambe maritima L. English common name: sea kale Also: scurvy grass, sea cole [The name scurvy grass is best reserved for Cochlearia officinalis L. Information on the culinary uses of C. officinalis is given in Small (1997).] French common name: chou marin (m) Also: crambe maritime, crambé maritime, crambe, crambé

Description and taxonomy Sea kale is a perennial herbaceous plant with a fleshy rootstock. It is native to the coastal areas of the Baltic Sea, Black Sea, and Atlantic coastal areas of Europe (Clapham et al. 1987). Cultivated plants are indistinguishable from wild plants. Early in the season, the leaf petioles become quite large and fleshy before the leaf blades expand. These young leaves are the only edible portion of sea kale and are blanched for the market (Péron 1990). Sea kale was first cultivated in Britain in the 18th century, and later in parts of the United States (Halpin 1978).

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Uses Sea kale is eaten raw, or boiled (for 4 min) like asparagus. Peeling the petioles is unnecessary before consumption. The flavor of the young petioles resembles that of cabbage, but with a fine hazelnut taste. Sea kale is eaten along with, or as an accompaniment to, shellfish, fish, or meat dishes (Péron 1989a). The large, thick leaves of sea kale are conspicuous and showy, and C. maritima can be grown in an ornamental border. Example recipe

Sea kale with hollandaise sauce (Buishand et al. 1986)

Importance Sea kale is commercially raised as a minor crop in Britain (Buishand et al. 1986). Commercial production has been carried out in some areas of northern France since 1988 (Péron 1990). No information seems available on amounts or value of sea kale production in Canada, if any.


Sea kale prefers a rich, light loam that is deeply prepared with considerable organic matter (Halpin 1978).

Climate

Sea kale is a hardy cool-season plant. The plant performs best in a cool, moist climate, such as found in coastal areas of Canada. This crop grows in full sunlight (Halpin 1978).


Propagation is usually by seeds, but root cuttings can also be employed to start this unusual crop. From seed, sea kale takes 3 or more years to reach maturity and is planted in a temporary nursery bed the first year. Seeds are sown indoors, or outdoors as soon as the soil can be worked in the spring. Seeds should be sown about 2 cm deep in rich soil. Seedlings are thinned outdoors to a spacing of 12–15 cm. The following spring, sea kale is transplanted to a permanent bed and is ready for harvest in 2 or more years. A well-managed bed will produce for 6 or more years (Halpin 1978; Stephens 1978). In most parts of Canada, sea kale should be covered with sufficient mulch to prevent freezing during the winter. The roots are damaged by temperatures below –15°C (Péron 1990). The best root cuttings for propagation are 1 cm in diameter and 10–12 cm long, taken from the straight side roots or “thongs” that grow out from the main root. The thinnest or distal (far) end is cut on a slant and the thicker end is cut straight. The thongs are usually collected in the autumn, bunched together, and stored in damp sand under cool temperatures until planting time. The cuttings are planted as soon as the soil can be worked. If the thongs are moved the same autumn to a new location they should be planted slightly deeper and

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mulched with a thick layer of leaves or hay (Halpin 1978). The thongs have a high capacity for regenerating shoots (Péron 1990). Laboratory micropropagation of sea kale has been studied (Drew and Fellows 1986). Sea kale plantlets (derived from petioles) successfully developed, but the process was slow. Harvest and storage

Sea kale can be harvested each spring. As the young leaves emerge, they are blanched by heaping soil around them or by covering them with a suitable device, such as a pot, to exclude light. The young petioles are harvested when they are 10–15 cm long and while they are crisp and tender, before the leaves start to expand substantially. The leaves are snapped off at ground level, like asparagus (Stephens 1978). Péron (1990) noted that yield per acre of sea kale was similar to that of asparagus. Sea kale can also be forced indoors, like Belgian endive (Cichorium intybus L.). In commercial tests (Péron 1989a, 1990) the rootstalks were dug up in the autumn, set in a peat moss substrate, and transferred to a dark forcing chamber at 15°C and 85% relative humidity, at a density of 150–200 rootstalks per square metre. The etiolated leaves were ready for harvest in 28 days. The yield per plant was found to be between 30–120 g, depending on the amount of root biomass. Home gardeners can force the plants in boxes or pots covered with 5 cm of rich loam soil, placed in a warm dark place, and watered when required. Harvest takes place in 5–6 weeks (Halpin 1978). Sea kale will store for up to 1 week under refrigeration (Buishand et al. 1986).

Cultivars

Cultivars are unavailable for this essentially wild plant. Sea kale does not seem to be listed in any Canadian seed catalog, but can be obtained in Canada through some British and American seed catalogs. Bettencourt and Konopka (1990) listed institutions that conserve sea kale germplasm.


The ancient Romans stored pickled sea kale aboard ships and fed it to the crews to prevent scurvy on long voyages, hence the common name “scurvy grass” (Stephens 1978).

Problems and potential Further research needs to be conducted on production (plant breeding, physiological, and agronomic studies) and marketing

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(product positioning and packaging). Sea kale would need to be deeply mulched to prevent frost damage to overwintering roots in most of Canada. This crop is likely to remain a curiosity, occasionally grown in home gardens. However, because it is so unusual, it has potential to interest consumers, so its commercial possibilities deserve exploration.

Selected references Halpin 1978; Péron 1989b, 1990.

Cucumis Cucumber Cucurbitaceae Gourd family Cucurbitacées, famille de la courge

Genus notes Cucumis has about 30 species of annual, tender, herbaceous vines, native to Africa and southern Asia (Singh 1990). Several species have been domesticated (Bailey and Bailey 1976), as noted below. Cucumis anguria L., West Indian gherkin (French = concombre Angurie, concombre à cornichons) is probably derived from an African progenitor. It may be cultivated in Canada as a novelty. Although it is sensitive to frost and cold, it can be grown in the Canadian climate because it requires only 2–3 warm months to produce fruit. The fruits are used mostly in pickles but are also eaten as a cooked vegetable and incorporated into curries. In North America, so-called gherkins of commerce usually are small or immature cucumbers of C. sativus. The following three domesticated species are discussed in detail: Cucumis melo L., cantaloupes, melons, and Chinese cucumber, probably of west African origin Cucumis metuliferus E. H. Mey. ex Schrad., African horned cucumber Cucumis sativus L., common cucumber. The genus Cucumis, perhaps surprisingly, contains both vegetables (cucumbers) and fruits (melons). Some taxonomists have considered melon plants to be so divergent from cucumbers that they have placed the melons in their own separate genus, Melo. However, this treatment is not widely accepted, and indeed some variants are used as both a vegetable and a fruit (see our treatment of African cucumber later). Further illustrative of the bridge between cucumbers and melons, some variants of C. melo are sometimes called “cucumber melons.” Outside Canada, cucumbers and their relatives are used in many, interesting ways. For example, C. myriocarpus Naud., a wild cucumber of South Africa, is used by the Sutos as a purgative. A decoction of the plant is employed to “purify” a man about to marry a widow. An overdose (of the plant) may be fatal.

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Chinese cucumber This species, Cucumis Melo L., is quite variable, with many distinct types of cultivars chosen for different fruit characteristics. This complexity has led to various artificial infraspecific classifications based especially on the fruit. The following varieties are grown in Canada (Whitaker and Davis 1962; Nonnecke 1989): var. conomon (Thunb.) Mak., Chinese cucumber or Oriental pickling cucumber, originated in Asia and discussed below var. inodorous Naud., the honeydew melons, widely grown in commerce var. reticulatus Ser., the cantaloupes or muskmelons, also widely grown in commerce Other varieties are recognized but are not relevant to Canada at this time. They include a recently developed pickling melon called “melofon” that is similar to pickling cucumbers. It has been bred for its high yield and once-over mechanical harvesting (Nerson et al. 1990). Still another variant is the “chito” melon (marketed in North America under the names melon apple, vine peach, orange melong, and vegetable orange). This plant is mainly used as an ornamental and is available through Canadian seed catalogs. It develops globular to oblong fruits 5–8 cm long, with white cucumberlike flesh; the fruits have been used to make “mango pickles.” Some authors have interpreted all domesticated members of C. melo as subsp. (or var.) melo (Jeffrey 1980). The wild type has been distinguished as var. agrestis (Naud). Greb. and is probably African in origin (Bailey and Bailey 1976). The taxonomy and nomenclature of this species require more study.

Names Scientific (Latin) names: Cucumis melo L. var. conomon (Thunb.) Gre. English common name: Chinese cucumber French common name: concombre chinois (m) [translated literally from English, for this book]

Description and taxonomy Chinese cucumber is an annual, herbaceous vine. It should not be confused with the conventional field cucumbers of commerce that belong to C. sativus L. However, the fruit resembles the familiar cucumber in shape and color, although it can grow much longer (up to 50 cm in length) than field cucumbers. The fruit has a thin, light green skin, and the flesh is crisp with a delicate flavor;

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there are few seeds. The fruit is also “burpless” (i.e., it does not cause gas to develop in humans, whereas burping of gas occurs in some people after they ingest field cucumbers). Chinese cucumbers are known as “uri” in Japan and “yueh kua” or “kee chi” in China. The origin is obscure. Chinese literature described this plant in A.D. 560 (Halpin 1978; Tindall 1983; Yamaguchi 1983).

Uses Chinese cucumbers provide long, tasty fruit suitable for salads, vegetable dishes, and pickles. In Japan the fruits are used for making expensive pickles, called “tsukemono,” after removing the skin and seeds and preserving in sake (Halpin 1978; Yamaguchi 1983). Example recipes

Chinese cucumber soup (Halpin 1978) Honolulu Chinese cucumber (Herklots 1972)

Importance Chinese cucumber is grown in many parts of Asia and, to a lesser extent, in tropical areas around the world. This crop is of minor importance in Canada and the United States. Unknown amounts of chinese cucumber are imported for specialty markets in Toronto and perhaps other major centres (Anonymous 1989).


Chinese cucumbers perform best in a loamy soil, rich in organic matter, with a pH near neutral (Yamaguchi 1983).

Climate

Chinese cucumbers should be planted outdoors when the soil has warmed and all danger of frost has passed. The optimum temperature for growth is between 25 and 30°C, whereas development is retarded below 13°C. Adequate water is essential, so irrigation must be provided during dry periods, especially after the fruit starts to set (Halpin 1978; Yamaguchi 1983).


Propagation is by seeds after all danger of frost has past. Plants should be located where they will receive sun all day and should be beside a fence or trellis that will allow the vines to grow 2–3 m tall. The most important requirement is even and sufficient water throughout the growing season (Halpin 1978).

Harvest and storage

The fruits of Chinese cucumber grow longer than traditional slicing cucumbers, from 35 to 50 cm, and only 2–5 cm thick. To prevent twisted or bent development of fruits, the plants should be grown on trellises. The fruits can be hand-picked when small for use as pickles. For use as a vegetable, Chinese cucumbers should not be picked until they are about 30 cm or longer and taste pleasant and sweet. Timely harvest of mature fruit ensures a continuous supply. The harvested

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fruit do not store for long before they become limp and lose their crispness (Halpin 1978). Example cultivars

Burpless Hybrid, China, China long, Japanese Long Pickling. Several Japanese cultivars have been selected based on color differences. Nakamura and Ishiuchi (1985) discussed trials of Japanese cultivars. Bettencourt and Konopka (1990) listed institutions in various countries conserving C. melo germplasm.


In Japan, Chinese cucumbers are marketed as “yard-long cucumbers.” Athough they likely would not reach 1 m in length under Canadian growing conditions, they may grow to 0.5 m (Halpin 1978). In China the plant is usually allowed to trail over the ground instead of being provided with trellises (Herklots 1972). Several crops of Chinese cucumbers are grown in Taiwan as a short-term vegetable in rice paddies during the summer months (Herklots 1972).

Problems and potential Chinese cucumber is likely to remain an oddity in Canadian home gardens. Because of the need to elevate the plant stems for proper growth of fruit and because of the high labor requirement for harvesting, commercial possibilities are limited.

Selected references Halpin 1978; Yamaguchi 1983.

African cucumber

Names Scientific (Latin) name: Cucumis metuliferus E.H. May. ex Schrad. English common name: African cucumber, kiwano Also: African horned cucumber, horned cucumber, horned melon, jelly melon, hedged gourd, English tomato French common name: melon à cornes (m) Also: metulon

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Description and taxonomy African cucumber should not be confused with the field cucumber (C. sativus L.). African cucumber is an annual trailing vine that produces orange to red fruit, 8–13 cm long. The thick skin is studded with conical protuberances tipped with soft or hard spines (Jeffrey 1980; Dane 1983). African cucumber is also known as African horned cucumber or horned cucumber because of the protuberances on the fruit. The cultivated plant is little changed from the wild form. The interior is a mass of green, translucent, slightly mucilaginous juice-sacs (Morton 1987). Although it is usually consumed as a fruit (i.e., for dessert), the African cucumber is also used as a somewhat exotic vegetable as noted below. African cucumber is native to southern Africa where it was used by the Bushmen. It has been proposed by Mallick and Masui (1986) to be the progenitor of melon, C. melo L. (including muskmelons, honeydew melons, and Chinese cucumber).

Uses African cucumber’s seeds and pulp, but not the flesh, are eaten raw, generally as a dessert, mixed with sour cream, sugar, cream cheese, yoghurt, orange juice, or other ingredients. The flesh can be poured over honeydew and cantaloupe balls (Morton 1987). It can be mixed into drinks with vodka (Sweet 1987). While primarily used as a fruit it also may be used as a vegetable, for example in stir-fries or as a flavoring in vegetable or meat dishes. The flavor has been described as “subtle banana–lime.” However, the fruit may have an unpleasant aftertaste (Morton 1987). Example recipes

Horned melon with shrimp salad (Richardson 1990)

Importance The fruits are grown commercially in New Zealand and are exported to several countries under the trade name “kiwano” (Morton 1987). African cucumber is of no commercial importance in Canada. The crop is also produced in Kenya, Israel, and the United States.


African cucumber, like other cucumbers and melons, performs best in loamy soils, rich in organic matter.

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Climate

The African cucumber should be planted in warm soil, after all danger of frost has passed, where it will receive full sunlight. Irrigation is beneficial during dry periods (Morton 1987).


Propagation is by seeds. Optimum germination occurs between 20 and 30°C. Sweet (1987) recommended that seeds be selected from fruits that do not exhibit any unpleasant aftertaste. Occasional weeding may be needed.

Harvest and storage

African cucumbers are mottled dark green when young and are hand-picked when they turn orange to red. Harvesting of ripe fruit provides continuous production of new flowers and fruits. In commercial production, thick-padded gloves are required during harvesting for protection against the sharp spines. Prior to packing the fruit, the ends of the spines are blunted by a grinding wheel. The fruits are packed in single-layer trays (Sweet 1987). African cucumber will remain in good condition for up to 6 months without cold storage (Morton 1987), and indeed keeps better at room temperatures than under refrigeration.

Example cultivars

African cucumber is available from some Canadian garden catalogs. Commercial cultivars have been selected in New Zealand. Bettencourt and Konopka (1990) listed institutions in various countries conserving African cucumber germplasm.

Additional notes African cucumber is considered a noxious weed in sugar cane plantations in Australia, where it is controlled with herbicides and fruit disposal to prevent reseeding. It has been considered for inclusion under Federal Noxious Weed Regulations in the United States (Morton 1987). Curiosities

In Nigeria the fruits are “rather bitter and not eaten.” In the Kalahari region of South Africa they are ingested by game animals and, in times of necessity, are consumed by the Bushmen and fed to cattle. The leaves reportedly have been cooked and eaten (Morton 1987). The foliage contains saponins giving a strongly frothing extract (Morton 1987).

Problems and potential African cucumber has only recently become available to Canadians through seed catalogs. It will probably remain as an oddity of limited use in home gardens in Canada. However, it has been grown outdoors recently at Agassiz Research Station (Agriculture Canada) in British Columbia. Experimentation is continuing to see if a commercial market is possible in southern B.C. Fruits were imported into Los Angeles in 1986, but many buyers were put off by the unpleasant aftertaste (Morton 1987). The plant

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clearly requires selection to become commercially attractive. The bitter aftertaste can persist for an hour, and some clones from the native source of South Africa are inedible. Because the distasteful flavors are considered to be under genetic control, potential growers should obtain seeds from fruits that do not exhibit any unpleasant aftertaste (Sweet 1987). Aside from its novelty, the only obvious, commercially desirable character of the fruits is their long storage life. Having this character means, however, that cheap foreign importation into Canada is possible. African cucumber may be useful for the genetic improvement of other crops. Interspecific hybridization trials between African cucumber and melon, C. melo, intended to transfer genes for resistance to pests and disease into melon, were discussed by Fanourakis (1988).

Selected references Keith and Renew 1975; Morton 1987; Sweet 1987; Benzioni et al. 1991; Mendlinger et al. 1992.

Common cucumber

Names Scientific (Latin) name: Cucumis sativus L. English common name: cucumber French common name: concombre (m) [Variants include concombre anglais (English cucumber), concombre de serre (greenhouse cucumber), and cornichon (gherkin, pickling cucumber).]

Description and taxonomy Cucumber is an ancient Old World vegetable that probably originated in India and spread westward to ancient Egypt and Greece. The cucumber was introduced into China in pre-Christian times. Columbus brought cucumber seeds to Haiti

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on his second voyage and their use spread from there. Cucumbers are naturally herbaceous vines but some so-called “bush-type” cultivars do not trail far over the ground. There are main forms of domestic cucumber, subsp. sativus, used in North America (Schultze-Motel 1986). The field cucumber is black- or white-spined. The English forcing cucumber sets fruits without the requirement for sexual fertilization, and the fruits are seedless. It generally develops black spines. Through hybidization, some white-spined English greenhouse cucumbers are now available. The Sikkim cucumbers are small, stocky plants producing large, reddish brown fruit marked with yellow (Nonnecke 1989). Sexual expression in cucumbers is complex. Some cucumbers are monoecious (having male and female flowers on the same plant). Others, including most field-grown cultivars, are primarily gynoecious (mostly with female flowers, but with a few male flowers). There are also hybrids that are gynomonoecious (which have mostly female flowers but bear a few flowers that are hermaphroditic (with both male and female parts on the same flower)). Such hybrids are usually high-yielding. Field cucumbers are insect-pollinated. In commercial production, the English telegraph use of two beehives per hectare provides adequate greenhouse cucumber pollination for maximum production. The English forcing cucumbers are generally grown in greenhouses to produce seedless fruit. Pollination by insects would cause seeds to form and change it to a more gourdlike fruit, thus making the product unmarketable. Proper production of these cucumbers requires meticulous care but results in seedless, bitterness-free, easily digestible, spineless, long cucumbers. Recent introductions of so-called “open-pollinated” English cucumbers can be grown outdoors on trellises. They produce both male and female flowers, and all the male flowers must be removed to prevent insects from pollinating the female flowers, which would result in unuseable fruit. “Burpless” cucumbers have been selected to prevent burping, which affects some individuals after eating cucumbers. As noted earlier, Chinese cucumbers (C. metuliferus) are burpless. Pickling varieties are mostly white-spined, although some black-spined varieties are also used. Picked when small and immature, they become the “gherkins” of commerce. A wild type, subsp. agrestis Gabaev (Schultze-Motel 1986) (var. hardwickii (Royle) Alef. of some authors [Lower and Edwards 1986]), is found in the Himalayan region of Asia and will cross readily with the cultivated cucumber. Some authors speculate that subsp. agrestis is related to the progenitor of the cucumber (Lower and Edwards 1986). This wild form is being used in many cucumber breeding programs.

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Uses Cucumbers are generally eaten raw, peeled or unpeeled, and added to salads. They are also cooked and used hot or cold in soups and vegetable dishes. Pickling varieties are used in relishes, chutneys, and pickles. Small immature pickling cucumbers are the “gherkins” of commerce (Nonnecke 1989). Example recipes

Baked stuffed cucumbers (Morash 1982) Braised salmon with cucumber sauce (Morash 1982) Chilled beet and cucumber soup (Morash 1982) Cucumber and herded goat cheese canapés (Levy 1987) Cucumber mousse (with radish sprouts) (Blanchard 1975) Cucumber soup with yoghurt (Tudge 1980) Sautéed cucumbers with dill (Levy 1987) Senfgurken (pickles) (Morash 1982) Sunomono (Japanese noodle and cucumber salad) (Ornish 1990)

Importance Cucumbers are an important crop worldwide, with annual production often exceeding 10 000 000 t (Yamaguchi 1983). Cucumbers are one of the most important vegetables in Canada, representing about 5% of the value of the fresh vegetable industry. Domestic production provides about two thirds of demand for combined processing and fresh cucumber markets (Coleman et al. 1991). Greenhouse-grown Ontario cucumbers represent the highest value class of cucumber crop in Canada. Ontario is the major table and pickling cucumber producer in Canada, with lesser amounts grown in other provinces.


Field cucumbers require soils with pH at or near neutrality. Heavier clay loam or silty loam soils, high in organic matter, provide the best production. High amounts of nitrogen are important. Greenhouse cucumbers are often grown on bales of hay or other growing media, allowing for close regulation of nutrients and water (Adamson and Maas 1981).

Climate

Field cucumbers are sensitive to cool weather and suffer if temperatures fall below 10°C. Soil temperature should be 25–35°C for seed germination, with minimum temperature of 18°C. Although cucumbers develop deep root systems, irrigation is essential during dry periods for maximum fruit production (Nonnecke 1989).


Propagation is generally by seeds. Pickling cucumbers are almost always direct-seeded after the soil warms. For the table or slicing cucumber it is desirable to use greenhouse transplants, which result in mature fruits before the direct-seeded crop. This timing provides a price advantage. Various types of plastic mulch and coverage by plastic tunnels have been used to provide warmth during cool periods and to reduce water stress (Nonnecke 1989).

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In greenhouse culture, seeds are usually treated for damping-off disease and germinated on blotters or other moist substrates at a temperature of 25°C. Young seedlings are then placed in individual containers. Once plants are large enough, they are transplanted into the final containers. Cucumbers grown in successive plantings about 6 weeks apart provide a continuous supply year-round (Adamson and Maas 1981). Harvest and storage

Example cultivars

Slicing or table cucumbers are hand-picked. Repeated harvesting of ripened fruits ensures continuous production of additional cucumbers. For good quality, fruits should be uniformly green with no sign of yellow (indicating over-maturity). Storage temperature range is limited to 12–13°C. Below 10°C chilling injury results and above 15°C yellowing occurs. The fruit can be hydrocooled. Cucumbers can be stored for 10–14 days at 95% relative humidity. English greenhouse cucumbers are film-wrapped to retain moisture. Pickling cucumbers have been mechanically harvested for several decades. However, field studies have shown that hand-harvesting at 2- or 3-day intervals surpasses the yield possible from once-over mechanical harvesting. It is especially economical to handpick high-priced gherkins. Pickling cucumbers are stored like slicing cucumbers (Nonnecke 1989). Slicing cucumbers: Gynoecious hybrid slicing cucumbers: Dasher II, Revenue, SliceKing Open-pollinated slicing cultivars: Marketmore, Straight Eight, Straight Nine Burpless slicers: Amira, Jazzer, Sweet Slice Bush cucumber cultivars: Pot Luck, Salad Bush, Spacemaster English greenhouse cucumbers: Aricia, Farbio, Mustang, Super Sandra Open-pollinated English cucumber: English Telegraph Novelty cucumbers: Crystal Apple, Lemon. Pickling cucumbers: Trailing pickling cucumbers: Lucky Strike Bush-type pickling cucumbers: Arkansas Little Leaf, Bush Baby, Bush Pickle. Trials of cucumber cultivars in Montreal were discussed in Malo and Bourque (1992). Bettencourt and Konopka (1990) listed institutions in various countries that conserve cucumber germplasm. Facciola (1990) provided an extensive description of cucumber classes and cultivars available in the United States.


The Roman Emperor Tiberius (42 B.C. to A.D. 37) had cucumbers on his table daily, summer and winter, making it necessary to grow them out of season using artificial methods (Grieve 1978). Cucumber has long been employed for its purported cosmetic properties. Cleopatra ate pickles in the belief that they enhanced

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her beauty. The flesh is rubbed on to keep the skin soft and white. It is supposedly cooling and soothing to irritated skin, such as that caused by sunburn. Cosmetic soaps and bubblebaths are sometimes made with cucumber (Grieve 1978). The Italian navigator Amerigo Vespucci (1454–1512), who contributed his name to “America,” supplied his ships with pickles, believing that they helped sailors survive scurvy. Pickles contain vitamin C, which combats the disease, although probably in insufficient amounts to make much difference. The term “cowcumber,” sometimes used today disparagingly, was the usual way 17th century English writers referred to the cucumber.

Problems and potential Cucumbers are subject to various disease pathogens and physiological disorders. Jarvis (1992) reviewed important cucumber diseases in Canada. In Canada, field cucumbers provide 70% of the volume of total cucumber production; the rest are grown in greenhouses. Most field cucumbers are used for pickling. Greenhouse cucumbers are sold entirely on the fresh market. Domestic production expanded by about 9% during the 1980s because of increased greenhouse production. Domestic production supplies about 90% of processed cucumbers and 50% of fresh cucumbers (Coleman et al. 1991). Increased use of greenhouse production could reduce the amount of fresh cucumbers imported into Canada, which represents about half of all fresh cucumbers used in this country.

Selected references Adamson and Maas 1981; Lower and Edwards 1986; Ali-Khan and Zimmer 1989; Nonnecke 1989.

Cucurbita Cucurbitaceae Gourd family Cucurbitacées, famille de la courge

Genus notes The genus Cucurbita has more than 20 species, all originating in the New World (Bailey and Bailey 1976; Jeffrey 1980; Bates et al. 1990; Singh 1990). Cucurbita can be divided into a group of mesophytic plants (adapted to moderately moist habitats) and a group of xerophytic plants (adapted to very dry conditions). The cultivated species originated from mesophytic species. Five species are cultivated, all of which can be grown as perennials in warm climates (Andres 1990). The following four cultivated species are discussed below: C. argyrosperma, C. maxima, C. moschata, and C. pepo. Not described here is C. ficifolia Bouché, fig-leaf gourd or Malabar gourd, which is cultivated in alpine areas of Mexico south to Chile and grows at elevations up to 2000 m in the tropical Americas. There the fruits are used as human food. In Asia this species is used primarily as fodder for livestock. In Japan and Holland, greenhouse cucumbers are grafted to the rootstocks of C. ficifolia for winter production (Andres 1990). The four cultivated Cucurbita discussed below have developed such similar fruit forms that all four species have cultivars commonly known as pumpkins, three as winter squash, two as summer squash, and two as gourds. The following table gives common names, classes, and example cultivars for each species (adapted from Bailey and Bailey 1976; Mansour and Baggett 1985a; Merrick and Bates 1989). Canadian statistics for “squash” are not separated by individual species. All “summer squash” and most “pumpkins” grown in Canada belong to C. pepo, whereas “winter squash” or “squash” may refer to several species. The discussion of the economics of “squash” in Canada appears in the section on C. pepo under “Importance.” Male flowers of Cucurbita may be distinguished from female flowers by the prominent ovary of the latter, which appears as a young, undeveloped fruit. Fertilization of the female flowers by pollen from the males is necesary before fruit will set. Long days (16 h or more of sunlight) and high night temperatures, as might occur in the early growing season, generally induce the male flowers to develop, and shorter day length and cooler nights cause female flowers to form. On occasion, gardeners are confronted with the frustrating situation of having only unproductive male flowers develop.

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Nomenclature of pumpkins, squash, and gourds for four species of Cucurbita.1 Pumpkin, squash, or “gourd” Pumpkin

Species C. argyrosperma ‘Ja‘Japanese Pie’ ‘White Cushaw’ “Sweet Potato” ‘Sweet Potato’

C. maxima ‘A‘Atlantic Giant’ ‘Mammoth Prize’

C. moschata “B‘Buckskin’

Summmer Squash

Winter Squash

“Buttercup” ‘Sweet Mama’ ‘Honey Delight’

Gourd

“Butternut” ‘Zenith Hybrid’ ‘Butternut Supreme’

C. pepo ‘Ja‘Jack O’Lantern’ ‘Small Sugar’

“Green elongated” ‘Zucchini Select’ ‘Cocozelle’ ‘Vegetable Marrow Bush’ “Yellow elongated” ‘Golden zucchini’ ‘Gold Rush’ “Flat-shaped” ‘Scallopini’ ‘White Scallop’ “Acorn” ‘Table King’ ‘Autumn Queen’

“Hubbard” ‘Golden Hubbard’ ‘New England Blue Hubbard’ “Delicious” ‘Golden Delicious’

“Other” ‘Vegetable’ ‘Spaghetti’

“e‘Turk’s Turban’

““‘Nest Egg’ ‘Spoon’

1Names with single quotations are example cultivars, those with double quotations are cultivar classes. Empty boxes indicates that the species does not have cultivars of this type.

Cucurbita argyrosperma pumpkins

Names Scientific (Latin) name: Cucurbita argyrosperma Huber Scientific synonym: Cucurbita mixta Pang. English common name: pumpkin Also: squash French common names: citrouille (f), courge (f)

Description and taxonomy The name of this species was recently changed from C. mixta Pang. to C. argyrosperma Huber (Merrick and Bates 1989). Subspecies argyrosperma contains all the cultivated types of the species.

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Evidence for domestication of C. argyrosperma traces to 5200 B.C. near Oaxaca in Mexico. In Mexico, fruits with large, edible seeds rather than edible fruits have been selected. The seeds are sold commercially in Mexico and Guatemala. Farther south the immature fruits are used as a vegetable. In northern Mexico, selections have been made for both edible seeds and fruits (Merrick 1990). All the commercial cultivars are “pumpkins” and are herbaceous annuals. Only a few commercial varieties of C. argyrosperma exist and are represented by the “cushaw” and “Sweet Potato” classes. The wild form of C. argyrosperma, subsp. sororia (L.H. Bailey) Merrick & Bates, is indigenous to Mexico, Central America, and the southwestern United States, where it is locally abundant. It is collected from the wild in Mexico (Merrick 1990), where the saponin-containing fruit pulp produces suds useful for washing clothes and animals and the seeds are employed as a vermifuge for intestinal worms.

Uses The fruits are used as cooked vegetables and also in dessert dishes. Example recipes

Pumpkin cheese cake (Morash 1982) Turkey dinner swan song soup (Morash 1982)

Importance Cucurbita argyrosperma is of minor importance in Canada, where only a few cultivars are available from Canadian garden catalogs. It is grown in home gardens, but not commercially.


Warm soils are essential for germination and growth. Abundant organic matter improves fertility and moisture retention. Soil pH should range between 6.5 and 7.5.

Climate

Optimum soil temperatures for germination are 21–35°C. Below 13.5°C germination is prevented, and plant growth stops at 10°C. Irrigation may be required because abundant water is essential, especially during fruiting (Nonnecke 1989).


Propagation is by seeds, precision-planted after all danger of frost is past. However, most commercial operations will use transplants. Black plastic mulch may be beneficial in cooler regions.


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Harvest and storage

Pumpkins are not harvested until the rind is hard. These fruits are normally hand-picked from home gardens in Canada. It is not uncommon to allow the fruits to be exposed to frost before harvesting. To prolong storage life, the fruits may be held for up to 10 d at 27–30°C with 80% relative humidity (Nonnecke 1989).

Example cultivars

Few cultivars are available for C. argyrosperma. The name “Sweet Potato” denotes C. argyrosperma. Some Canadian garden catalogs sell the cultivar Delicata (or Sweet Potato). The cultivar name, Delicata, normally refers to a type of winter squash of C. pepo; it is unclear whether this cultivar name is sometimes used for C. argyrosperma. Another cultivar, Sweet Dumpling may also be C. argyrosperma. Bettencourt and Konopka (1990) listed institutions in various countries conserving C. argyrosperma germplasm. Facciola (1990) provided an extensive description of cultivars available in the United States.

Problems and potential This pumpkin will probably remain an occasional plant of home gardens in Canada, rather than a commercial vegetable, because of an abundance of more competitive cultivars of C. pepo.

Selected references Bates et al. 1990; Merrick 1990.

Cucurbita maxima squashes and pumpkins

Names Scientific (Latin) name: Cucurbita maxima Duch. English common names: winter squash, pumpkin French common names: courge (f), citrouille (f) [Variants designating cultivars or cultivar classes include courge Hubbard (hubbard squash), courge Buttercup (buttercup squash).]

Description and taxonomy Cucurbita maxima is the most distinctive of the four cultivated species discussed here. The cultivated forms are often put under subsp. maxima and Schultze-Motel (1986) described a formal taxonomy to

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reflect different cultivar groups. There is evidence of prehistoric domestic use of this species in South America, the earliest dating to about 1800 B.C. Domesticated cultivars include pumpkins, winter squash, and gourds. The wild progenitor of the cultivated forms is probably subsp. andreana (Naud.) Filov (Bates et al. 1990; Decker-Walters et al. 1990).

Uses

Hubbard squash

The fruits are cooked by baking or steaming and are eaten as vegetables or added to stews, casseroles, and meat dishes. Several types of desserts can also be made, including pies and tarts (Nonnecke 1989). Example recipes

Gratin of squash with rutabaga (Morash 1982) Puréed buttercup squash (Schneider 1986) Sautéed grated squash (Morash 1982) Spinach, leek, and (Hubbard) squash pancakes (Levy 1987) Squash pancakes (Morash 1982) Squash yeast rolls (Morash 1982) Steamed squash with ginger and apple (Morash 1982) Winter squash (Hubbard) gratin with fresh tomato sauce (Levy 1987)

Importance Common classes of C. maxima winter squash include buttercup and Hubbard squash. These keep for long periods and are available in stores during autumn and winter. The numbers and value of these squash types in Canada have not been determined. Cucurbita maxima is grown widely throughout the temperate zones but is considered a minor commercial food crop (Loy and Broderick 1990). More information on the economic importance of pumpkins and squash in Canada is presented under C. pepo.


Warm soils are essential for germination and growth. Abundant organic matter improves fertility and moisture retention. Soil pH should be between 6.5 and 7.5.

Climate

Optimum soil temperatures for germination are 21–35°C, with germination prevented below 13.5°C. Maximum germination occurs at the higher temperatures. Plant growth stops at 10°C with optimum


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growth between 18 and 24°C. Irrigation may be required because abundant water is essential, especially during fruiting (Nonnecke 1989). Propagation and cultivation

Propagation is by seeds precision-planted after all danger of frost is past. However, most commercial operations will use transplants placed in polystyrene trays for easier transport. Black plastic mulch may be beneficial in cooler regions. It is suggested that to grow cultivars such as Atlantic Giant for competition, only one female flower per plant should be allowed to set fruit, and the plants should be watered well.

Harvest and storage

Winter squash and pumpkin are not harvested until the outer skin (or rind) is hard. These may be mechanically harvested if destined for processing, or hand-harvested if intended for the fresh market. In Canada, winter squash may be exposed to frost before harvesting. To prolong storage life, some winter squash are held up to 10 days at 27–30°C with 80% relative humidity. Banana squash are simply held in cool rooms (Anonymous 1988b; Nonnecke 1989).

Example cultivars

Turk’s Turban

Pumpkins: Atlantic Giant (which has held the world’s record for the biggest pumpkin, according to some Canadian garden catalogs, at least 235 kg), Mammoth Gold. Winter squash: Buttercup class: Buttercup, Golden Nugget, Honey Delight, Sweet Mama. Hubbard class: Golden Hubbard, New England Blue Hubbard, True Green Hubbard. Gourds: Turk’s Turban. Bettencourt and Konopka (1990) listed institutions in various countries conserving C. maxima germplasm. Facciola (1990) provided an extensive description of classes and cultivars available in the United States.


Seeds of C. maxima were abraded and mixed with water to form an emulsion that was once used to treat bowel problems (Grieve 1978).

Problems and potential The commercially important cultivars of C. maxima grow as prostrate vines. Recent studies have shown that large-fruited bush-type cultivars have increased productivity in comparison with the vine types. Developing acceptable strains of small-fruited bush-types of

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C. maxima is more difficult. They usually set too heavy a fruit load for the size of the plants, which results in wide variability of fruits and, therefore, less commercial importance than viny cultivars (Loy and Broderick 1990).

Selected references Bates et al. 1990; Loy and Broderick 1990.

Mammoth pumpkin

Cucurbita moschata squashes and pumpkins

Names Scientific (Latin) name: Cucurbita moschata Duch. ex Poir. English common name: crookneck squash Also: winter squash French common name: courge musquée (f)

Description and taxonomy Cucurbita moschata is a domesticated species, whose wild ancestor may be extinct. A formal taxomony reflecting cultivar groups was presented by Butternut squash Schultze-Motel (1986). This species was domesticated in North America and includes pumpkins and a well-known winter squash (butternut squash). It is the only cultivated species that will cross with the wild xerophytic group of Cucurbita (see “Genus notes”). Cucurbita moschata is considered by many to be closest to the ancester that gave rise to cultivated members of the genus Cucurbita (Singh 1990).

Uses This squash is used as a baked or steamed vegetable and is added to soups, stews, casseroles, and meat dishes. It may also be made into desserts such as pies (Nonnecke 1989, Rozin 1992).


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Example recipes

Calabaza strips with whole-wheat pasta (Schneider 1986) Squash crême (custard) (Morash 1982) Squash and meat pie (Morash 1982) Squash soup (Morash 1982)

Importance The “Butternut” class of squash belongs to C. moschata. Statistics on the value of this squash in Canada seem unavailable. It is sold in stores during the autumn and winter months. Although fruits of C. moschata are grown commercially and sold fresh or processed in Canada, this squash is grown less frequently than C. pepo. A discussion of the economic importance of pumpkins and squash is found under C. pepo.



Climate

Optimum soil temperatures for germination are between 21 and 35°C, with germination prevented below 13.5°C. Optimum growth occurs between 18 and 24°C, and plant growth stops at 10°C. Irrigation may be required because abundant water is essential, especially during fruiting (Nonnecke 1989).


Propagation is by seeds, precision-planted after all danger of frost is past. However, most commercial operations will utilize transplants grown in greenhouses. Black plastic mulch may be beneficial in cooler regions.

Harvest and storage

Fruits intended for fresh market are usually hand-harvested, whereas those intended for processing are usually harvested mechanically. However, because squash and pumpkins damage easily, fruits that are harvested mechanically are processed immediately. Winter squash and pumpkin are not harvested until the rind is hard. These types may be mechanically harvested if destined for processing. In Canada, it is not uncommon to allow these types to be exposed to frost before harvesting. To prolong storage life, some winter squash are held up to 10 days at 27–30°C with 80% relative humidity. Butternut squash are best stored at 10°C with 50% relative humidity. They will store for 2–3 months. It is important to prevent the development of hollow necks and subsequent weight reduction resulting from moisture loss (Nonnecke 1989).

Example cultivars

Butternut class: Butterbush, Butternut Supreme, Early Butternut, Waltham Butternut.

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It is not clear whether any cultivars of the pumpkin type are available in Canada. Bettencourt and Konopka (1990) listed institutions in various countries conserving C. moschata germplasm. Facciola (1990) provided a description of cultivars available in the United States.


Forms of C. moschata were grown in the New England states in the late 17th century. These were known as “crook neck” or “crane-necks” (Hedrick 1972).

Problems and potential The potential for increased market for this type of squash in Canada is unclear, although probably limited.

Selected reference Bates et al. 1990.

Cucurbita pepo squashes and pumpkins

Names Scientific (Latin) name: Cucurbita pepo L. English common names: pumpkin, squash Also: vegetable marrow, zucchini French common name: citrouille (f), courge (f) [Numerous designations for specific cultivars or cultivar classes include courge à cou tors (crookneck squash), courge poivrée & courgeron (acorn squash), courge spaghetti (spaghetti squash), zucchini and courgette (zucchini).]

Description and taxonomy Cucurbita pepo is an annual herbaceous vine. It includes cultivars of pumpkins (the common pumpkins of Halloween), summer squash (marrow, zucchini, scallopini, cocozelle, some types of crook necks, fordhooks, and scallop),

Pumpkin


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winter squashes (acorn, and vegetable spaghetti), and ornamental gourds. The earliest remains of this species are seeds, more than 9000 years old, from the valley of Oaxaca, in Mexico. Several studies (Decker 1988; DeckerWalters 1990) suggest that C. pepo was independently domesticated twice, from different “species.” Domesticated C. pepo has been divided into two subspecies, as follows: Subspecies pepo originated in Mexico. The wild C. fraterna L.H. Bailey, from northwestern Mexico may be a progenitor of this subspecies. Further analysis is Vegetable marrow required to determine if C. fraterna might best be considered part of C. pepo (Decker 1988). This subspecies includes pumpkins, gourds, and marrows. Subspecies ovifera (L.) Decker originated in the eastern United States and is now found in southern Texas; it had a much wider distribution in antiquity. Some plants can escape and sustain themselves in the wild and are known sometimes as C. texana (Scheele) A. Gray.

Uses Summer and winter squash are cooked in vegetable dishes and are added to stews, soups, casseroles, and meat dishes (Nonnecke 1989). Some, such as zucchini, are also eaten raw in various ways, for example sliced into salads. Zucchini is also added to various breads, muffins, and other baked goods. Pumpkins are generally used in desserts but may be added to stews. The shell can be used as a container to heat soup or stew. Gourds are also used as decorative items. Male flowers and young leaves of pumpkins and squashes are sometimes eaten, and the seeds of some cultivars may be roasted and consumed as a confection. Example recipes

Beef stew with pumpkin in a pumpkin shell (Morash 1982) Carrot soup with zucchini croutons (Tudge 1980) Chilled pumpkin soufflé (Morash 1982) Cranberry pumpkin muffins (Morash 1982) Custard marrow with salad (Buishand et al. 1986) Delicata squash halves baked with cream and basil (Schneider 1986) Easy pumpkin scramble (vegetable dish) (Morash 1982) Fried cheese-stuffed squash flowers (Schneider 1986) Garlic-scented zucchini with celery (Levy 1987) Pumpkin ginger ice cream (Morash 1982) Pumpkin purée (Buishand et al. 1986) Pumpkin with soup inside (Morash 1982) Squash stew (Morash 1982)

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Stuffed acorn squash (Morash 1982) Summer squash orange cake (Morash 1982) Susan Mayer’s curried summer squash soup (Morash 1982) Vegetable spaghetti with red pepper, pine nuts, and basil (Schneider 1986) Vegetable spaghetti with tomato sauce (Buishand et al. 1986) West Indian pumpkin soup (Rozin 1992) Whole stuffed courgette (zucchini) flowers (Leggatt 1987) Zucchini stuffed with corn and cheese (Morash 1982)

Importance Canadian economic statistics for “squash” are unavailable for the individual species of Cucurbita. Most “pumpkins” and all “summer squash” grown in Canada belong to C. pepo, but “winter squash” or “squash” may include several species. Canada usually grows more than 500 ha of commercial “squash” and 500 ha of commercial “pumpkins” annually, mostly in Ontario and Quebec, with smaller amounts in British Columbia, the Maritime Provinces and the Prairie Provinces. With respect to sales of fresh Cucurbita, major Canadian markets generally import no more than one quarter of pumpkins, import about two thirds of both summer and winter squash (excluding zucchini), and import four fifths of zucchini (Anonymous 1990a, 1991c; Dubé et al. 1990).



Climate

Optimum soil temperatures for germination are 21–35°C, with germination prevented below 13.5°C. Optimum growth is from 18 to 24°C, and plant growth stops at 10°C. Irrigation may be required because abundant water is essential, especially during fruiting (Nonnecke 1989).


Propagation is by seeds, precision-planted after all danger of frost is past. However, most commercial operations will use transplants. Black plastic mulch may be beneficial in cooler regions.

Harvest and storage

Fruits for fresh market are usually hand-harvested, whereas those for processing are usually harvested mechanically. However, because squash and pumpkins damage easily, fruits that are harvested mechanically are processed immediately. Summer squash, such as zucchini, vegetable marrows, and scallop classes, are hand-picked for the fresh market. The fruits must be harvested continuously before they become too mature. Short intervals between harvests promote ongoing fruit production. Appropriate harvest size for zucchini is 5–7 cm in diameter and less than 17 cm in length. Scallop squash are harvested at 7.5–10.0 cm in


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diameter. Summer squash are susceptible to damage from rough handling. The fruits are precooled prior to shipping and held at 7–10°C and 90–95% humidity. Storage time is about 1 week. Winter squash and pumpkins are not harvested until the outer skin (or rind) is hard. These types may be mechanically harvested if destined for processing. In Canada, it is not uncommon to allow exposure to frost before harvesting. To prolong storage life, some winter squash are held up to 10 days at 27–30°C with 80% relative humidity. Acorn squash are best kept at 10°C with 60% relative humidity. They will store for 5–8 weeks. It is important to maintain greeness on acorn squash as yellowing indicates that the flesh is becoming stringy (Anonymous 1988b; Nonnecke 1989). Example cultivars

Pumpkins: Ghost Rider, Conneticut Field, Happy Jack, Small Sugar. Zucchini Summer squash: Green elongated zucchini: Black Jack, Seneca Select, Zucchini Dark Green, Zucchini Select Yellow elongated: Burpee Golden Zucchini, Gold Rush, ‘Seneca Prolific, Sundance Flat-shaped: Scallopini. Winter squash: Acorn or pepper squash: Table King, Table Queen, Tay Belle Novelty squash: Delicata, Vegetable Spaghetti. Gourds: usually marketed simply as “mixed ornamental gourds.” Recent trials of pepper and zucchini squash Vegetable scallop cultivars in Montreal were discussed by Malo and Bourque (1992). Breeding of squash cultivars was described by Whitaker and Robinson (1986). Bettencourt and Konopka (1990) listed institutions in various countries conserving C. pepo germplasm. Facciola (1990) provided an extensive description of classes and cultivars available in the United States.


The word squash apparently traces to Native Americans occupying the northeastern Atlantic coast. Authors have suggested that squash is derived from either “askutasquash” or “squoutersquashes.” To this day, the word squash is primarily used only in North America, the names pumpkin or marrow being applied overseas (Hedrick 1972). Squash and gourd bees (mostly found in warmer climates than Canada’s) commonly enter the closing flowers of Cucurbita at dusk to pass the night protected and leave at dawn when the flowers open. A widespread fallacy is that squash and pumpkin will cross-pollinate with other genera of the cucumber family, watermelon (Citrullus) and muskmelon (Cucurbita), causing the fruit of one to take on the taste attributes of another.

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Record-size pumpkins have generally come from the Northern United States and Canada, close to the 45th parallel. In 1993, Herman Bax of Brockville, Ontario, raised a pumpkin that weighted 449 kg (990 lb), although more recently pumpkins weighing more than 1000 lb have been grown in the United States. At the close of the 1996 season, the record pumpkin wighed 481 kg (1061 lb). Most champion pumpkins are derived from Howard Dill’s Atlantic Giant. Competitors for the title of biggest pumpkin may let their vines sprawl over at least 160 m2 and use 10 m3 of composted manure per plant. One champion grower is rumored to grow his pumpkins over an old septic field. In midsummer, prize-winning pumpkins can take up 4000 L of water per week, and put on 14 kg of weight per day. At times these giants grow so fast that they explode.

Problems and potential The pumpkin market is almost completely satisfied by domestic growers. However, summer squash requires imports, particularly zucchini (domestic production represents only about a quarter of demand of demand [Dubé et al. 1990]). The potential for growth in summer squash and zucchini production is limited by the short Canadian growing season and short storage time (about 1 week) for the more perishable fruits.

Selected references Whitaker and Robinson 1986; Decker 1988; Bates et al. 1990; DeckerWalters 1990.

Cynara Compositae (Asteraceae) Sunflower family Composées, famille de la marguerite

Genus notes The genus Cynara has about 12 perennial herbaceous species native to the Mediterranean region and the Canary Islands. Two species are grown as garden vegetables: C. cardunculus L., cardoon, and C. scolymus L., globe artichoke (Bailey and Bailey 1976). Some authors have concluded that cardoon and globe thistle should be placed in the same species, as they are interfertile (Thomsen and Barbe 1986). Both species will also cross with the closely related wild Syrian artichoke, C. syriaca Boiss. (Zohary and Basnizky 1975).

Cardoon

Names Scientific (Latin) name: Cynara cardunculus L. English common name: cardoon Also: edible thistle, cardoni, cardone French common name: cardon (m)

Description and taxonomy Cardoon may have been one of the first vegetable plants used by humans. The related globe artichoke, C. scolymus, was probably derived from cardoon (Zohary and Basnizky 1975; Bailey and Bailey 1976). A form of cardoon with weak, small spines is cultivated in some Mediterranean countries and is particularly popular in France. Local cultivars are available in these countries. The wild form has comparatively stout spines, about 2 cm long. This form is still found in southern Europe and northern Africa. Cultivated cardoon has escaped in some parts of the world. It has become a noxious weed of grazing lands since being introduced in Australia, New Zealand, South America, and parts of California, where it is known as “artichoke thistle.” Charles Darwin observed the plant in Argentina in the last century and declared that “…probably several hundred square miles

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are covered by one mass of these prickly plants…” (Thomsen and Barbe 1987). The tender young leaf stalks are the part of the plant mainly consumed, much like celery (the undeveloped tender flower stalks of cardoon are also sometimes eaten). They are usually grown in darkness so that they become white and soft.

Uses Cardoon should be used as a cooked vegetable, prepared like French fries, served with oil and lemon juice à la grecque, or added (cooked) to tossed salads. It is also used in soups and pickles (Halpin 1978). The taste has been said to be a combination of artichoke, celery, and salsify. In the past, a yellow dye has been obtained from cardoon (Grieve 1978). In some parts of Spain, an extract of dried flowers was used for curdling milk and for making cheese. The aerial part of the plant has been used as feed for cattle. Example recipes

Braised cardoons (Schneider 1986) Cardoon à la crème (Buishand et al. 1986) Cardoon–potato salad (Schneider 1986) Cardoons in onion cream sauce (Schneider 1986) Cardoon tempura with anchovy sauce (Richardson 1990) Deep-fried cardoons (Schneider 1986)

Importance Cardoon is grown as a vegetable in Italy, France, Spain, Argentina, and Australia but is little known in North America, particularly in Canada (Halpin 1978). It does not seem to be grown commercially in the United States or Canada.


Cardoon grows best in rich well-drained soils containing high amounts of organic matter. The soil pH should be near neutral.

Climate

This tender perennial will not tolerate frozen soils. It is a cool-season plant, growing best between 13 and 18°C. Cardoon must be well watered to prevent the petioles from becoming hollow and bitter-tasting (Halpin 1978; Yamaguchi 1983). The plants should be grown in full sun.

Cynara (cardoon, globe artichoke)

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Cardoon is started indoors from seed and is transplanted outside after all danger of frost.

Harvest and storage

The leaf stalks can be hand-picked when they are 30–50 cm long. However, all trace of the leaf blade must be removed because it tastes very bitter. The preferred method is to wait until the plants are about 1 m tall, tie the leaves with a cord, and wrap the leaf stalks with a lightproof covering. After 3–4 weeks the stalks will be blanched. If wrapping of the leaves is done on a wet day, and the leaves remain wet, they could rot. Alternatively, plants can be dug up with their roots in autumn and put in a box of soil in a basement where they will become blanched. The roots could be kept in a box of earth in a cold room for the winter, where they can survive until the next growing season for replanting (Halpin 1978; Blondin 1983).

Example cultivars

Cardoon is occasionally found in Canadian seed catalogs. Bettencourt and Konopka (1990) listed countries with institutions conserving cardoon germplasm.


Cardoon was said to receive a higher price than any other herb in the markets of ancient Rome (Grieve 1978). In some parts of Spain, the down attached to mature seeds is substituted for rennet in the making of cheese. A strong infusion is made overnight and is added the next morning to the milk (Grieve 1978). Large amounts of cardoon were once consumed by pregnant women in the belief that this would give them male children (Richardson 1990).

Problems and potential Cardoon is a large plant, growing over 1 m tall, so it requires considerable room. Its spiny leaves are an annoyance (Halpin 1978). Cardoon is not winter-hardy in the Canadian climate, so it may remain a garden curiosity grown only by people interested in unusual plants.

Selected references Halpin 1978; Blondin 1983; Richardson 1990.

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Globe artichoke

Names Scientific (Latin) name: Cynara scolymus L. English common name: globe artichoke Also: artichoke French common name: artichaut (m)

Description and taxonomy Globe artichoke is a thistly, perennial herbaceous plant with bristly leaves. It is not known in the wild. It originated in the central and western Mediterranean region and was carried to Egypt and farther eastward 2000–2500 years ago. During the Roman empire, artichokes marinated in vinegar were considered an expensive delicacy (Richardson 1990). Some authors recommend that globe artichoke and cardoon, C. cardunculus, be placed in the same species. Globe artichoke is probably derived from cardoon (Zohary and Basnizky 1975; Bailey and Bailey 1976), and the form first eaten by the ancient Romans and Greeks may have been cardoon (Ryder et al. 1983). Globe artichoke disappeared from use after the fall of the Roman Empire and resurfaced around A.D. 1400 in Naples and Sicily. It spread through Europe and America but never became as popular as in southern Europe (Ryder et al. 1983). The edible part of the globe artichoke is derived from a head of flowers enclosed by bracts. What most people perceive as large flowers, as with other members of the sunflower family, are made up of a crowd of small flowers (commonly termed florets). The bases of the bracts are eaten, along with the fleshy receptacle, i.e., the end of the stem on which the head of flowers develop (in different plant families, receptacles may develop into different parts of the flower and fruit). If the immature flower heads are not removed, they mature into flowers but usually produce few viable seeds. The artichoke of commerce is globular to cone-shaped, with a tender, meaty edible interior, in the heart of which is the inedible “choke,” easily removed after the artichoke has been cooked. Artichokes are known for their unusual, delicate flavor, but are not eaten raw. The surrounding bract-like leaves vary from very small at the interior to quite large and with sharpened tips towards the exterior. The larger bracts are edible at their base, but progressively tougher towards the exterior of the artichoke.


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Uses Globe artichoke is cooked and served hot or cold with melted butter, salad dressing, or a sauce. This vegetable may be steamed, boiled, or stuffed and eaten bract by bract, or the hearts can be marinated or battered and fried. The nutty flavor at the base of the bracts is prized. Canned or frozen small buds or “hearts” are used as hors d’oeuvres (Nonnecke 1989). In Italy, the edible portions are dried and used mainly in soups (Grieve 1978). They are also used in Italy to make a bitters-type liqueur (Ryder et al. 1983). Example recipes

Artichokes à la barigoule (Richardson 1990) Artichoke Provençal vegetable and garlic feast (Levy 1987) Artichokes and baby onions Antiboise (Levy 1987) Artichokes with tomato Béarnaise sauce (Levy 1987) Colorful vegetable blanquette (Levy 1987) Marinaded artichoke hearts (Buishand et al. 1986) Rice pilaf with artichoke hearts, carrots, and toasted almonds (Levy 1987)

Importance Although globe artichoke is grown in many parts of the world, nearly 95% of world production is from countries bordering the Mediterranean, with Italy, Spain, and France accounting for 80% of the crop. For example, Spain produced 338 000 t of globe artichoke on 25 300 ha in 1987 (Hinton 1991). The major growing area in North America is California. In 1991, 2274 t were imported into Canada (Anonymous 1992a), where there is no commercial production.


Globe artichoke will grow in a wide range of substrates but performs best in deep, fertile, well-drained soils high in organic matter.

Climate

Globe artichoke is cultivated in temperate areas of the world. It is a cool-season perennial, which overwinters by means of its fleshy taproot. The plant is resistant to cold and tolerates heavy frost. However, frost damages the flower stalks, and temperatures below 2°C seriously retard growth. The plants can withstand dry periods, but irrigation is desirable while flower heads are forming. The optimum growing temperatures are 13–18°C. In hot, dry climates the flower buds are tough and the production period is shortened (Yamaguchi 1983).


When grown from seeds in Canada, seedlings should be started indoors and transplanted after danger of frost. However, few cultivars

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are grown from seeds, because the progeny are so variable and mostly inferior in quality to the parents. Globe artichokes are normally reproduced vegetatively. The basal stem pieces with attached root sections, commonly referred to as “stumps,” are used. Axillary buds at the base of the stumps develop into shoots that initiate roots and become established. These rooted offshoots are employed to expand the number of plants. Growers prefer this method to using seed, because vegetative propagation produces plants that perform more reliably (Nonnecke 1989). In commercial production, globe artichokes are replaced every 3 years, although plants will live for more than 15 years (Ryder et al. 1983). Harvest and storage

Flower buds are harvested before the scalelike leaves covering the flowers begin to open. In Canada, there will probably be few flower heads to harvest in the first year. The plant should be cut back to ground level for the winter. Globe artichokes will require some type of winter protection to keep the roots from freezing. They may be covered well with insulating leaves, straw, or styrofoam, or the roots may be dug up and stored in a cold room. If roots are stored indoors they can be replanted as soon as the soil can be worked in the spring. In the second and subsequent years harvesting can begin as flower heads form. The artichoke is hand-harvested. Commercial globe artichokes are hydrocooled immediately to 0°C with 90–95% high humidity, placed in polyethylene bags, kept for 3 weeks at –0.5°C, and thereafter below 5°C (Ryder et al. 1983; Nonnecke 1989).

Example cultivars

Green Globe Improved, Violetto. Bettencourt and Konopka (1990) listed institutions in several countries that conserve artichoke germplasm.


In an ancient Greek legend, a maiden’s beauty so angered the gods that they transformed her into an artichoke (Farrell 1978). Etymologically, artichoke is usually interpreted as a corruption of its Arabic name, “al’qarshuf.” An alternative, perhaps more colorful explanation holds that the name is derived from the old North Italian (Ligurian) term “cocal,” meaning a pine cone, with which the artichoke seemed comparable (Henrico 1987). Artichoke had a reputation in Europe as an aphrodisiac, as well as a cure for jaundice and for coughs (Farrell 1978). Catherine d’Medici, who married Henry II of France when she was 14, was widely held in disdain because her notorious appetite for artichokes was interpreted as excessive use of an aphrodisiac. Artichokes were considered a luxury item in Europe several hundred years ago. The private physician of Louis XIII claimed that they inflamed the senses and warmed the blood. Artichokes were prescribed for the wealthy to treat insomnia, liver and kidney problems, and as a beauty treatment (Richardson 1990).


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Extracts of artichoke have reputed medicinal value for gastrointestinal activity, blood-clotting time, capillary resistance, heart activity, and neutralization of some toxins (Ryder et al. 1983).

Problems and potential Globe artichoke does not seem suited to commercial production in this country (Nonnecke 1989) and may remain principally an oddity of home gardens in Canada. However, there has been some experimentation in eastern Canada (Beauregard and Barré 1992), and the possibility exists of finding cultivars and growth techniques that could create at least limited domestic commercial production in Canada. Coupled with the problem of adapting the plant to Canadian agriculture is the problem of adapting Canadian tastes to the artichoke. Although this vegetable is popular in the Old World, it has yet to become established in the mainstream of North American food culture. Like many of the more obscure vegetables discussed in this book, few know how to select, cook, or eat an artichoke.

Selected reference Ryder et al. 1983; Richardson 1990.

Daucus Carrot Umbelliferae (Apiaceae) Carrot family Ombellifères, famille de la carotte

Genus notes The genus Daucus consists of about 30 species, including annuals, biennials, and perennials, found mostly in Europe, Africa, and western Asia; a few species occur in the Americas and Australia (Small 1978b). The centre of distribution is the Mediterranean Circle countries. None of the species is native to Canada. Only one species, discussed below, has been domesticated, although several have been employed in folk medicine.

Names Scientific (Latin) name: Daucus carota L. English common name: carrot French common name: carotte (f)

Description and taxonomy Daucus carota is widely considered to be the most problematic of the about 3000 species of the family Umbelliferae; indeed, it is often thought to include several species. Both wild and domesticated phases consist of numerous intergrading variants, and there is little agreement on the most appropriate nomenclature for the many forms that have been described. The latest taxonomic treatment is that of Small (1978b), which recognizes two basic lineages, informally called subspecies aggregates (subsp. agg.). The subsp. agg. carota contains both wild and domesticated forms. All the wild forms of this group are in subsp. carota, whereas all the domesticated forms are in subsp. sativus (Hoffm.) Arcangeli. (Alternatively, domesticated carrots are sometimes taxonomically segregated from wild carrots as D. carota var. sativus Hoffm. or D. sativus (Hoffm.) Roehl.) The wild forms are widespread as weeds in temperate regions of the world and

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occur in much of southern Canada excepting the central prairies (Dale 1974). The cultigens of subsp. agg. carota were selected from the wild plants of this group. Large, white-rooted carrots, used as fodder for livestock, may represent an intermediate stage between the white-rooted wild carrot and domesticated carrots. It appears that two distinct groups of cultigens arose. The “eastern carrot,” D. carota var. atrorubens Alef., seems to have been selected in central Asia. The earliest records of this kind of carrot come from 10th century Persia and Asia Minor. Although claims are often made that carrots were cultivated before the Christian Era, it cannot be determined whether carrot or parsnip (Pastinaca sativa L.) was grown, because the latter was known quite early and is poorly distinguished in ancient writings from carrot. The eastern carrot is characterized by purplish storage organs, quite unlike the familiar, orange-rooted “western carrot,” D. carota subsp. sativus var. sativus. The orange pigments of the western carrot are carotenes (“provitamin A”). The western carrot seems to have first become well known about A.D. 1600 in The Netherlands; before then, orange carrots were completely unknown. The parentage of the western carrot is obscure. Perhaps it arose, at least in part, from the eastern carrot; or it may have been independently selected, from wild European carrots. Until the last century, carrots intergrading between the western and eastern were raised in different parts of the Old World. Today, the orange carrot has almost completely displaced the eastern carrot, which is found mostly in germplasm collections. Some hybrids between the eastern and western carrots are also known. For example, Kintoki, a form with blood-red roots, is in widespread use. Various kinds of orange carrot are now recognized mostly based on root shape (Babb et al. [1950] and Banga [1963] gave extensive descriptions and classification). These types are placed in cultivar groups with names like Oxheart, Chantenay, Danvers, Nantes, and Imperator. Size varies from large roots of the order of 200 g to “baby” carrots of 5–10 g. “Forcing” carrots are ones that have been selected for harvest while young. Relatively short carrots are not as productive as long ones, but are easier to grow in many types of soils. Also, stump-rooted or half-long cultivars are often sown for early market. The subsp. agg. gingidium contains mostly relatively dwarf forms found near or in maritime habitats along the Old World sea coasts. These variants are all wild but are not weedy; they rarely occur outside their coastal native habitat. This group does not appear to represent any part of the ancestry of the modern domesticated carrot. Wild carrots have whitish, stringy, woody, branched, thin, unpalatable roots. Populations of the wild plants are either annual or biennial, or they develop some plants that are annual and others that are biennial. Early in the first year, the wild roots are relatively fleshy and are sometimes consumed by collectors of wild foods—a potentially dangerous practice, because some extremely poisonous species of the carrot family mimic the wild carrot. (Conium

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maculatum L., poison hemlock, believed to have furnished the potion that killed Socrates, is the deadliest mimic.) Upon bolting, the plant uses up the reserves stored in the root. Accordingly, most cultivars of carrot have been strongly selected to be biennials, so that the root remains fleshy and edible the first year. The fleshy storage organs are a combination of root and hypocotyl (anatomically, the embryonic tissue between the true root and the true stem). The upper portion of a carrot is derived from hypocotyl, the lower from the primary root. Therefore a carrot is not strictly a “root,” as it is popularly termed, because it has some tissues of nonroot origin. However, the term root will suffice for most purposes.

Uses The carrot is a widely consumed vegetable, its orange-yellow color adding attractiveness to foods. Carrots are eaten raw, consumed as juice, or cooked in various ways. Carrot serves as a Coreless long red flavoring ingredient of soups and sauces and is a chief carrot component of mixed vegetable dishes. In addition to its primary use as a vegetable, roots of D. carota are sometimes used as fodder. Wild carrot foliage is occasionally eaten by dairy cattle to the extent that the milk is tainted, although the foliage is nevertheless nutritious for livestock. Among the minor uses of carrots, the following may be mentioned. Carrot syrup is sometimes employed as a sweetening agent. Alcoholic tincture of carrot seed is incorporated in French liqueurs. Carrot oil is used for flavoring and in perfumery. Roasted roots have occasionally been used as a substitute for coffee. Considerable honey is manufactured from bees visiting carrot, although the quality is poor. A variety with particularly large petals on the outer flowers is grown as an ornamental, and wild carrot inflorescences (responsible for the common names of the wild plant “Queen-Anne’s-lace” and “bird’s-nest”) are widely used in dried floral arrangements. Example recipes

Carrot and cabbage timbales (Morash 1982) Carrot soup with chives (Levy 1987) Carrot yeast bread (Morash 1982) Carrots with cranberries (Morash 1982) Carrots with raspberry vinegar (Levy 1987) Chanterelle feuilletés with vegetable julienne (Levy 1987) Chilled carrot soufflé (Morash 1982) Cream of carrot and celeriac soup (Morash 1982) Ginger-glazed carrots and turnips (Levy 1987) Rice pilaf with artichoke hearts, carrots, and toasted almonds (Levy 1987) Savory carrot pie (Osbourne 1954) Sweet carrot fritters (Morash 1982)

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Importance The carrot is one of the most important of cool-climate root crops. Annual world production is about 10 000 000 t (Nonnecke 1989). Carrot is also one of the most valuable crops in Canadian vegetable production. About three quarters is used for the fresh market, and a quarter for processing. About a quarter of fresh carrots but very little processed carrots are imported from the United States (Coleman et al. 1991). Ontario and Quebec are the main production centres, but carrots are grown in all provinces. In Quebec carrot is the second most important vegetable after the potato. The carrot is widely grown as a home-garden crop, in market gardens for local trade, and on truck farms for factory canning, shipping to various markets, or storage for winter markets. As reflected by such usages, carrots have excellent shipping and keeping characteristics.


Carrots require a deep, loose (friable), fertile soil with good water-holding capacity and freedom from stones and clods, to develop long, straight roots acceptable to the commercial market. Well-drained sandy loam, peat, or muck are ideal, but carrots can be grown on heavy soils with proper cultural practices. Carrots tolerate the wide pH range that occurs across production areas of Canada (Nonnecke 1989). Soils may be prepared by fertilizing and deep-cultivating them to 30–45 cm. About 75–80% of the Canadian carrot crop is grown on organic soils. In Ontario, the Holland Marsh near Bradford is the largest area of muck soils well-adapted to growing cool-weather crops such as carrots. In Alberta, carrots are most commonly grown on raised beds, about 50 cm wide and about 15–20 cm high (Anonymous 1975). Raised beds tested in sphagnum soils in New Brunswick were found to improve carrot growth by increasing soil temperature, maintaining soil moisture, and forming a deep seedbed. Carrot shape benefited particularly, and longer, thinner carrots were produced (LeBlanc and Thébeau 1990b).

Climate

The carrot is adapted to a cool climate with a long growing period free from extremes of temperature and moisture. For most orange-rooted cultivars, an optimum mean temperature is between 16 and 21°C. High temperatures early in the growing season are injurious, and continuous high temperatures in latter stages of development may reduce yield, retard growth, and promote a strong-flavored root. Temperatures below 16°C retard growth. For germination the soil temperature should be at least 4.4°C before seeding. The carrot is intolerant of drought and benefits from good rainfall distribution or irrigation (Anonymous 1975; Nonnecke 1989).


Propagation is by seed. Extensive directions for various regions of Canada are provided by Anonymous (1974, 1975, 1988a). Carrot seed germinates over a 2-week period and is limited if a crust forms on the soil surface. Seeds may be precision-or scatter-seeded, depending on

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the seeder. Seeding rates of 2.25–4.5 kg/ha are considered sufficient. To ensure uniform flow of the tiny seeds, pelleted seed is used that is covered with a minimum coating (about 3:1 finished weight over raw seed). The use of pelleted seed requires less seed than scatter seeders. When sowing in muck soils, a better seedbed results when a roller precedes the seeding equipment (Nonnecke 1989). Carrot seed is commonly imported into Canada, although there is some commercial production here, notably in British Columbia. Simpson et al. (1985) described carrot seed production in the Pacific northwestern states. Nearby wild carrots easily pollinate cultigens, and it is essential that seed be generated in areas free of the wild form. Seeds are usually produced by first growing a crop of mother roots called “stecklings.” These may be left in the ground in mild climates, to overwinter and produce seed the next season. In areas of severe winter, the stecklings are commonly harvested, stored overwinter, and replanted in the spring, at which time they bolt. Harvest and storage

There are three categories: carrots for fresh packing (whole and topped), carrots for processing, and finger or baby carrots. Commercially, fresh packing carrots are mechanically harvested in one operation that loosens the roots, lifts them by the tops, and cuts the tops off. Damaged and misshapen roots are removed to prevent two serious diseases of stored carrots, bacterial soft rot and Sclerotinia soft rot. Carrots may be piled in bins to a height of 3 m, if forced-air circulation is provided. Alternatively, pallet bins are widely used. Carrots grown in Ontario on muck soils are usually not washed prior to storage, but storage of carrots grown on mineral soils in Alberta and Nova Scotia appears better after washing. After harvest, roots should be cooled as quickly as possible to 0°C and maintained at this temperature together with 98% relative humidity. Carrots should keep 6–9 months with the latest application of storage technology. It might be permissible to store carrots in the same room as other root crops (beets, parsnips, and rutabagas) that have similar storage requirements. Ethylene production from some other vegetables and from fruits stored in the same room might cause carrots to acquire a bitter taste, so carrots should generally not be stored with fruits or with vegetables that might produce appreciable ethylene. Carrots with tops are hand-pulled, tied in bunches, and loaded for packing houses. They are then washed, hydrocooled, placed in waterproof cartons, top-iced, and shipped immediately. Storage temperature is 0°C with 95% relative humidity. Bunched carrots may be kept 10 days to 2 weeks if the tops are not crowded. While carrots for fresh market are often harvested before maturity, in a tender state, carrots for storage should be fully mature. Mature carrots are less prone to oxidative surface browning of abrasions (Franklin 1974; Nonnecke 1989). Finger or baby carrots are mechanically harvested with customized equipment adapted from the radish industry. A top-cutting device the width of the row cuts the tops before the carrots are dug. The harvested carrots are destined for fresh or processed (canned or

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frozen) market. They are sold fresh in cello bags stored similarly to bunched carrots (Nonnecke 1989). The home gardener may store carrots between layers of soil and straw in a half-buried container outdoors; or in root cellars at a humidity of at least 90% and at near-freezing temperatures. The carrot is a large-yielding crop. In the garden, a good yield is about 1 kg per 30–37 cm. In market gardens, a good yield is 200–280 bu/ha (1 imp. bu = 0.036 m3). Good yields for the cannery are commonly between 1100 and 1600 t/ha. Mazza (1989) discussed the relationship of methods of harvest and storage on the quality of carrots intended for canning, freezing, dehydration, and freeze drying. Example cultivars

Short Horn carrot

Baby or finger carrots: Baby Orange, Baby Sweet Hybrid, Little Finger, Minicor, Mini Express, Orbit, Thumbelina. Chantenay: Chantenay Long, Red-Cored Chantenay, Royal Chantenay, Touchon. Danvers: Danvers 126, Danvers Half Long, Processor II. Imperator: A-Plus, Hybrid Apollo, Imperator Special No. 58. Nantes: Coreless Amsterdam, Falcon II, Ingot, Lindoro, Pioneer, Rondino, Scarlet Nantes, Special Nantes, Tim Tom. (Some of the cultivars listed above are hybrids, others open-pollinated, and still others are crosses between the different classes of carrots.) Malo and Bourque (1992) described carrot cultivar trials in Montreal. Bettencourt and Konopka (1990) listed institutions in various countries conserving carrot germplasm. Facciola (1990) provided an extensive description of carrot cultivars available in the United States. Carrot breeding was discussed by Peterson and Simon (1986).

Additional notes Carrots are well known as a source of vitamin A (so are such foods of animal origin as fish-liver oils, butter, and egg yolks). Although carrots contain many nutrients, including proteins, carbohydrates, fats, calcium, phosphorus, iron, sodium, thiamin, riboflavin, niacin, and ascorbic acid, only vitamin A is considered important. A deficiency of carotene causes night blindness and may make one susceptible to infections of the eipthelial tissues of the eyes, the digestive glands, kidneys, respiratory system, and alimentary canal. Strictly, it is not vitamin A (retinol) but a precursor of this vitamin, carotene, that occurs in vegetable matter, and the mucous membranes of the intestines transform this into vitamin A (Mazza 1989). However, green vegetables are a greater source of vitamin A than carrots, and since a method of synthesizing carotene industrially was made available in 1947, synthetic vitamin A has been added to various foods. Nevertheless, carotene content continues to be considered desirable

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in carrots. Carotene concentration increases in young roots up to about 100 days after emergence. Carotene content is correlated with intensity of orange color, and therefore highly colored carrots are more desirable commercially, not only for their better appearance but also for their higher nutritive value. Carotene content is determined not only by cultivar, but also by growth conditions. For example, carotene concentration usually decreases at continuous temperatures of 21°C, and below 16°C. Curiosities

The Russian storyteller Anton Chekhov (1860–1904) wrote “You ask me what life is. That’s like asking what a carrot is. A carrot is a carrot, and there’s nothing more to know.” A toxic substance, carotatoxin, occurs naturally in carrots, but in such small concentration that it has little significance for normal consumers of carrots (Crosby and Aharonson 1967). Carrot tissue is an extremely popular “test tube” culture material. Human and carrot cells have been fused. The birds-nest-shaped fruit cluster of carrot has a remarkable mechanism for seed dispersal. The stalks are hygroscopic, so that when conditions are dry and suitable for seed dispersal they bend outward, exposing the fruits to wind and animals; when conditions are wet, they bend inwards, forming the familiar bird’s nest structure, which protects the seeds. Carrots are widely marketed with the leaves attached, because this suggests to the consumer that the product is fresh. However, the tops dry out the roots since the foliage draws away moisture, and to store such carrots after they are purchased the tops should be removed.

Problems and potential Carrot rust fly maggots and numerous diseases (Crête 1977) require continual attention when growing carrots. Canada is essentially self-sufficient in carrot production (Dubé et al. 1990). There is little potential for significant growth of commercial carrot production unless exports increase.

Selected references Banga 1963; Anonymous 1974, 1975; Dale 1974; Small 1978b; Mazza 1989.

Eruca Rocket Cruciferae (Brassicaceae) Mustard family Crucifères, famille de la moutarde

Genus notes The genus Eruca contains five annual to perennial herbaceous species, native to the Mediterranean region (Clapham et al. 1987). One species is cultivated and is discussed here.

Names Scientific (Latin) name: Eruca vesicaria (L.) Cav. English common names: rocket, arugula (pronounced a-roo-goo-la) Also: rocket-salad, salad rocket, roquette, rugula, rucola, Mediterranean rocket French common name: roquette (f)

Description and taxonomy Rocket is an annual or overwintering herb that is cultivated for its edible garlic-mustard-flavored leaves. The cultivated form is subsp. sativa (Mill.) Thell. (Clapham et al. 1987). The wild form, subsp. vesicaria, is native to the Mediterranean region and has been naturalized in parts of eastern Asia and North America. In Canada, rocket has become naturalized in waste and cultivated areas from Alberta to southwestern Quebec (Scoggan 1978–1979). Rocket has been used since ancient times and has been cultivated for centuries in Britain. The plant was grown in the New England states soon after colonization. Today it is seldom cultivated in North America, although it is still popular in many parts of Europe (Halpin 1978).

Uses In many European countries rocket is added to salads or consumed as a potherb. Raw leaves have a sharp, spicy, pungent flavor, resembling horseradish or watercress. The leaves add flavor to salads and are excellent in tomato dishes. Rocket can be lightly cooked or steamed with other greens. Older, bitter leaves can be cooked, puréed, and added to soups (Halpin 1978). However, the younger leaves are

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recommended as the older foliage become quite tough and bitter (Richardson 1990). Example recipes

Arugula and radicchio salad (Richardson 1990) Arugula Italian-style salad (Richardson 1990) Arugula soup (Morash 1982) Arugula, potato, and leek soup (Schneider 1986) Pasta with arugula, prosciutto, and tomatoes (Schneider 1986) Salad rocket à la Margarethe (Buishand et al. 1986) Warm arugula tossed with diced red onion and tomato (Schneider 1986)

Importance Rocket is occasionally available in specialty shops, marketed under various names, notably “arugula.” This crop is of minor importance in Canada. The seed is occasionally used as a source of an oil used in place of rape (Brassica napus L.) oil. Rocket is still very popular in Italy and in several Mediterranean countries, and market demand is increasing steadily in both central Europe and North America.


Rocket will grow in various substrates but does best on fine soils with high organic matter (Halpin 1978).

Climate

The species is adapted to cool temperatures and is therefore best planted early in the spring. The flavor becomes strong in older leaves and when the plant flowers during the summer. Supplying sufficient moisture causes the plants to grow rapidly and reduces the accumulation of sharp flavors in the leaves.


Propagation is by seeds sown in the ground as soon as the soil can be worked. Occasional cultivation will reduce competition from weeds. A continuous crop can be obtained by sowing seeds every few weeks.

Harvest and storage

The leaves are ready to harvest when the plants are 15–20 cm high. Flowering shoots should be removed to promote abundant growth. The foliage is strong-tasting, and frequent cutting is recommended to encourage growth of tender, flavorful young leaves. The leaves are best used fresh but can be stored for a few days in cool temperatures. Rocket can be frozen after blanching (like Swiss chard and spinach) for winter use.

Cultivars

Cultivars seem unavailable in Canada, although at least one Canadian garden catalog offers seed of rocket. Bettencourt and Konopka (1990) listed world institutions that house germplasm collections of this species.

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Probably because it seems exotic under the name “arugula,” rocket has become a favorite salad green of sophisticated yuppies, who have willingly paid fancy specialty store prices for it.

Problems and potential Flea beetles can gnaw small holes in the foliage of rocket. The wild germplasm that is needed to improve rocket by breeding is unfortunately in danger, because of unsustainable exploitation of the native populations in Europe, where massive harvesting of indigenous plants is occurring. Rocket will likely remain a vegetable of limited importance in Canada. It may be occasionally grown for local markets or for sale as an addition to salads in gourmet restaurants.


Foeniculum Florence fennel Umbelliferae (Apiaceae) Carrot family Ombellifères, famille de la carotte

Genus notes Foeniculum has three perennial species, native to the Old World (Bailey and Bailey 1976). One of these (F. vulgare) includes two cultivated varieties (Tutin et al. 1968; Bailey and Bailey 1976; Schultze-Motel 1986). Both kinds are grown for their leaves, used as a culinary herb and garnish, and for their seeds, employed as flavoring. As noted below, however, one variety is a vegetable. Variety dulce (Mill.) Batt. & Trab., with thin leaves and a nonbulbous base, is known as fennel. It is a perennial in milder climates but is grown as an annual in Canada. Stems, leaves, and seeds of fennel are used as a culinary herb for flavoring, as discussed in detail by Small (1997) Variety azoricum (Mill.) Thell. develops an edible swollen base composed of enlarged leaf bases and is known as Florence fennel. It is commercially grown as an annual and is discussed in detail below. It should be noted that some of the literature confuses varieties azoricum and dulce. For example, the recent authoritative The New Royal Horticultural Society Dictionary of Gardening (Huxley et al. 1992), at one point refers to Florence fennel as var. dulce and at another as var. azoricum. Foeniculum vulgare has become naturalized in many temperate countries and has been recorded on roadsides and dry fields in southwestern British Columbia, Alberta (tentatively), southern Ontario, and southwestern Quebec (Scoggan 1978–1979, who interpreted these records as occasional escapes from cultivation). A wild form, subsp. piperitum (Ucria) Cout., is a native perennial of the Mediterranean and southern Europe, where it grows on sea cliffs and has naturalized in waste places (Clapham et al. 1987).

Names Scientific (Latin) name: Foeniculum vulgare Mill. subsp. vulgare var. azoricum (Mill.) Thell. English common name: Florence fennel Also: finocchio (in Italy) French common name: foenouil de Florence (m) (Vilmorin-Andrieux 1885)

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Description and taxonomy Florence fennel is a perennial herbaceous plant that is grown as an annual. It develops an edible swollen base (a false bulb or pseudobulb) composed of enlarged leaf bases. Florence fennel is sometime known as “anise” or “sweet anise” (because of its anise flavor) but this name is appropriately reserved for a quite unrelated species also known as anise, Pimpinella anisum L., another member of the parsley family, used since classical times as a flavoring. Fennel has been used as a food since ancient Roman times. In fact there were few meats seasoned, or vingear sauces served, without fennel. It was also regarded as important for medicinal purposes. Florence fennel was described in English literature in the early 18th century (Hedrick 1972). Today it has fallen out of general usage except for some people of Mediterranean heritage, particularly from Italy. It is still used by herbal medical practitioners, particularly for stomach and intestinal problems (Halpin 1978).

Uses The base of the plant somewhat resembles celery and is grown in a similar manner. Indeed, Florence fennel has a mild, sweet taste, somewhat resembling celery, but with a mild licorice or anise flavor. The bulbous bases should be large and squat, with a pearly sheen and no sign of splitting, drying, or browning. This bulblike vegetable can be shredded, slivered, or diced and eaten raw in salads. The swollen leaf bases can be boiled, baked, sautéed, puréed, and added to casseroles, stews, soups, chowders, and pasta dishes. It is also excellent in stir-fries (Schneider 1986; Facciola 1990). Florence fennel is sometimes preserved by canning. The seeds of all forms of fennel are used in the food and flavor industry. The seeds of cultivated fennel are preferred to those of the wild forms. The flavor enhances meats, vegetable products, soups, salad dressings, breads, teas, and alcoholic beverages. Crushed seed has been used as a substitute for juniper in flavoring gin. The seed oil is used in condiments, liqueurs (anisette), soap, creams, and perfumes. The seeds are also valued for their medicinal qualities, purportedly alleviating gastrointestinal problems, stimulating lactation, and relieving colic (Halpin 1978; Simon et al. 1984; Splittstoesser 1990). Example recipes

Braised capon with fennel boats (Morash 1982) Braised fennel with peppers and olives (Levy 1987) Cream of fennel soup (Morash 1982)

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Fennel and tomato salad (Richardson 1990) Fennel Mornay (Morash 1982) Fennel salad Waldorf (Richardson 1990) Fennel salad with herbed crême fraîche (Levy 1987) Fennel with tomatoes, mushrooms, and herbs (Schneider 1986) Fennel à la grecque (Schneider 1986) Fennel, bean, and tomato soup (Morash 1982) Florence fennel casserole (Organ 1960) Lamb with Florence fennel (Buishand et al. 1986) Sautéed fennel (Morash 1982) Sautéed radicchio, mushrooms, and fennel (Schneider 1986) Sea bass roasted with fennel (Owen 1978)

Importance Florence fennel is produced commercially in several European countries including Italy, France, Spain, and Switzerland and is also grown in the United States. This fennel has become increasingly popular as a vegetable in the United States (Morales et al. 1991) and is imported to some supermarkets in Canada. It is uncertain if Florence fennel is raised commercially in Canada; this minor vegetable is grown mainly as a curiosity in home gardens. The vegetable form, as well as seeds of fennel, are sold for cooking and as a component of herbal medicines. In 1991, 1437 t of Florence fennel were unloaded at 10 major Canadian markets (Anonymous 1992a). Florence fennel statistics are sometimes confusingly listed as “anise”, for example in Anonymous (1989) and Anonymous (1992a). The commercial value of imported Florence fennel in Canada may exceed $2 million annually.


Florence fennel should be provided with loam soils, or muck soils rich in organic matter. The soil pH should be near 7.0 (Halpin 1978).

Climate

Florence fennel performs best in cool, moist climates and has a tendency to bolt (flower prematurely) in warm summer weather. It requires a continual supply of moisture throughout the growing season. Commercial plants are often grown on raised beds with overhead or trickle irrigation (Halpin 1978; Morales et al. 1991).


Propagation is by seed. In northern climates the seeds are best started indoors and transplanted in late spring. This start allows for greater control of stand establishment and plant density. Alternatively, the seeds are sown in July for an autumn harvest. Space between plants is optimum at about 20 cm to allow the bulb (swollen leaf bases) to best develop size and shape. In fact market demand and price are based primarily on bulb size, shape, and visual appearance. Frequent shallow cultivation reduces weed competition and improves water penetration into the soil. When the bulblike base of the stem begins to swell and the plant is about 25 cm tall, the leaf bases are blanched by

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covering them to keep out light. If light is allowed to reach the leaf bases, they develop an unpleasantly strong licorice flavor (Halpin 1978). Harvest and storage

The leaf bases are ready to harvest when they are 6–8 cm in diameter; if allowed to grow larger, they become bitter and stringy. Usually just prior to flowering, the top of the foliage is removed by cutting, the plant is pulled or dug by hand, and the roots are removed. The bulb with some remaining foliage is cleaned of soil and debris, washed, and stored under refrigerated conditions (Morales et al. 1991). Frost damages Florence fennel, so it must be harvested before freezing (Halpin 1978). Florence fennel can be stored for 2 weeks in a refrigerator, if packed in paper or plastic to prevent drying. Drying causes the leaf bases to become tough and fibrous (Buishand et al. 1986). If the leaf bases seem somewhat dehydrated, they can be reconstituted in ice water or a bowl of cool water in a refrigerator for an hour or so (Schneider 1986).

Example cultivars

The vegetable form of fennel is available in Canadian garden catalogs under the names “Florence fennel” or “finocchio.” It may appear either in the vegetable or the herb sections of catalogs. Forms of fennel grown for the flavorful leaves and seeds are also available. These are sold under such names as “sweet fennel” or “bronze fennel” (including the cultivar Rubrum). Bettencourt and Konopka (1990) listed institutions in various countries conserving fennel germplasm. Facciola (1990) provided a detailed description of Florence fennel cultivars available in the United States. Morales et al. (1991) examined leaf and bulb yields of several cultivars of Florence fennel, grown in Indiana. The cultivar Zefa Fino was found to be the highest-yielding cultivar.

Additional notes Oil of fennel causes dermatitis in sensitive individuals. There is some evidence that contact with the plant may result in phytophotodermatitis, a rash resulting from ingestion of the plant followed by exposure to sunlight. The volatile oil extracted from the seeds has caused nausea, vomiting, seizures, and pulmonary edema in humans after misuse (Mitchell and Rook 1979; Simon et al. 1984). Curiosities

In classical Roman times fennel was thought to improve eyesight. The early Anglo-Saxons attributed several mystical properties to the plant, including improving yields of other crops.

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Problems and potential Florence fennel is likely to remain of minor interest in Canada. It is most familiar to Canadians of Mediterranean heritage, who have a tradition of using this vegetable. The potential exists to fill some of the demand for this vegetable domestically. Already it is encountered as an “exotic” dish in fine European-style restaurants, so there may be an expanding commercial market in Canada as it is sold increasingly in supermarkets.

Selected references Halpin 1978; Simon et al. 1984; Schneider 1986.

Glycine Soybean Leguminosae (Fabaceae) Pea family Légumineuses, famille du pois

Genus notes Glycine consists of nine herbaceous species. Seven are wild perennials native to Australia and southwestern Asia, and two are annuals native to western Asia, including the cultivated soybean, discussed here (Hymowitz and Singh 1987).

Names Scientific (Latin) name: Glycine max (L.) Merr. English common name: soybean Also: soya bean, soja bean French common name: soya (m) Also: soja

Description and taxonomy Soybean is an annual herbaceous plant known only in cultivation. The domesticate is extremely variable because soybean has developed land races (primitive cultivated races) in East Asia. There are two main groups of cultivars (Tindall 1983; Hume et al. 1985). Determinate forms have a terminal bud that develops into an inflorescence. Virtually all soybeans grown closer to the equator than 36° are of this type. Indeterminate forms lack a terminal inflorescence, and flowering begins at lower nodes and develops towards the stem tip. Cultivars with this habit are grown in the northern United States and Canada. The wild relative of soybean appears to be G. soja Sieb. & Zucc., distributed throughout China and the adjacent areas of Russia, Korea, Japan, and Taiwan. It grows in fields, hedgerows, along roadsides, and riverbanks. Evidence based on chromosome and mitochondrial DNA

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studies supports the view that G. soja is the wild relative of soybean (Hymowitz and Singh 1987). A semiweedy form is known from northeastern China and is somewhat intermediate in morphology between G. max and G. soja. This variant has sometimes been considered to be either a separate species (G. gracilis Skvortz.) or a form of G. max. Some authorities have proposed that all three be considered as subspecies of G. max (Hymowitz and Singh 1987). Soybean is a domesticate of China. Current evidence suggests that it was employed during the Chou Dynasty from the 11th to the 7th century B.C., indicating that initial domestication took place during the Shang Dynasty (ca. 1700–1100 B.C.) or earlier ((Hymowitz and Singh 1987). The first specific reference to consumption of immature soybeans as a vegetable comes from the 2nd century B.C. (Lumpkin and Konovsky 1991). It was cultivated early in the histories of Korea, Manchuria, and Japan and was introduced to Europe in the late 1700s and to the United States in 1804. However, the potential of soybean in the Western World did not become realized until the 1930s. It is now widely cultivated in tropical and temperate areas (Tindall 1983).

Uses Soybeans are grown for their seeds that are rich in protein (average 40%) and oil (average 21%). In many industrialized countries, most of the crop is marketed for processing, which involves dehulling the seeds and extracting the oil. The edible oil is used in cooking and in the production of salad dressings, margarines, whipped toppings, coffee whiteners, icings, ice creams, confections, shortenings, frozen desserts, and soups. Most of the residual meal is used in livestock feeds. Soya flour is low in starch and lacks gluten, so it cannot be used alone in making bread. It is best employed as a protein supplement to foods; so soybean protein in various forms is added to flour or processed into protein concentrates and textured and modified proteins. As is well known, combining seeds of cereals and legumes often produces an excellent balance of essential amino acids for human nutrition1 (Singh and Singh 1992). This multipurpose crop has even been used as a coffee substitute. In many countries, soybeans are an important source of human food. “Soybeans are probably used in more ways than any other single vegetable” (Harrington 1978). In the Far East, the soybean is employed as food in many ways. Sprouts are popular, although not as common as mung bean sprouts. Soybeans are used as an immature green vegetable, often termed “vegetable soybean” (Shanmugasundaram 1991). The immature pods or shelled peas are cooked with various kinds of meats, rice dishes, and cereal. The seeds are employed to make “tofu” (bean curd), bean flour, soybean milk, soya sauce, and 1

Legume seeds are rich sources of protein, particularly the essential amino acid lysine, but are usually deficient in the sulfurcontaining amino acids methionine and cystine. By contrast, cereal grains contain lower amount of proteins, and these are deficient in lysine but adequate in sulfur-containing amino acids.

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various forms of fermented soybean (known in Japan as “miso,” “natto,” and “kinako” and in Indonesia and China as “temph” [Singh and Singh 1992]). The sauces produced by fermentation constitute the basic flavoring agents of Oriental foods. To produce soybean milk, used in parts of the East much like cow’s milk in the West, soy beans are ground and added to water. To form tofu, soybean milk is allowed to curdle. Tofu, a kind of boneless meat substitute used in the Orient, is now available in Western supermarkets. In southern Asia and developing African and Latin American countries, the crop is increasingly viewed as an important infant food (Hume et al. 1985). Seed colors of different variants range from yellow to gray and black. However, in Western commerce yellow seeds are usually demanded because use of brown or black seeds results in undesirable coloration. Black seeds are usually employed to make soya sauce. With the possible exception of corn, soybean surpasses all other crops in the diversity of its industrial usage. In addition to edible products, manufactured goods include soaps, resins, lubricants, rubber substitutes, paints, varnishes, enamels, inks, stains, adhesives, sealing and caulking compounds, linoleum, oilcloth, explosives, diesel fuel oil, and various industrial oils. For home use, immature pods are picked and boiled until tender. Butter or oil is usually not added to the pods because the seeds have a high oil content. Only the seeds are eaten, even when cooked in the pods. The shelled green seeds can be cooked with soy sauce or cooked like lima beans. Roasted dried seeds can be eaten like peanuts. Whole or flaked seeds are used in many vegetable and meat dishes (Harrington 1978). Soybeans can be sprouted and used like mung bean (Vigna radiata) sprouts. Because of the high protein content, they can be an important part of a vegetarian diet. Example recipes

Curried cream cheese roll (with soybean sprouts) (Blanchard 1975) Oatmeal cookies (with soybean sprouts) (Blanchard 1975) Oriental soybean sprout salad (Richardson 1990) Scrambled tofu and vegetables (Ornish 1990) Shrimp and cucumbers (with soybean sprouts) (Blanchard 1975) Soybeans Indienne (Buishand et al. 1986) Sweet and sour wok-cooked vegetables with tofu (Ornish 1990) Tofu treasures and crunchy vegetables (Shurtleff and Aoyagi 1979)

Importance Soybean is the world’s most important oilseed and grain legume crop. Worldwide, production is about 100 000 000 t annually (Singh and Singh 1992). The world’s largest producer is the United States, where nearly two thirds of all soybeans are grown (Hume et al. 1985; Singh and Singh 1992). Brazil and China are estimated to be responsible for 15% and 10%, respectively. In Canada, Ontario is the primary commercial producing province, planting over 400 000 ha annually

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(Anonymous 1991a). In 1996 Ontario harvested 1.91 million tonnes of soybeans from 764 900 ha, representing 88% of the total Canadian production. Vegetable soybean is a minor vegetable in Japan with 104 500 t grown on 14 400 ha in 1988. It is also grown in Taiwan, mostly for export to Japan. China, Thailand, Mexico, and the United States also grow vegetable soybean for export (Nakano 1991). Little information seems available on use of vegetable soybean in Canada. The Canadian Seed Growers’ Association noted that 1.4 ha of vegetable soybean was grown for certified seed in 1991 (Anonymous 1992e). In Canada, soybeans used for green vegetables are likely grown only in home gardens.


Cultivars have been selected that are adapted to different soils. However, well-drained sandy or clay loams high in organic matter are best. The pH should be above 6.0. Heavy clay soils are generally considered unsuitable because of difficulties in planting and emergence. Nevertheless, once emerged, soybeans are well adapted to such soils (Tindall 1983; Upfold and Olechowski 1988).

Climate

Soybean is adapted to hot climates. Soybeans begin to germimate at 10°C; at 25–30°C complete germination occurs in 3–4 days. Growth may be retarded at temperatures above 38°C. Commercially grown soybean cultivars are rated by the amount of heat (in corn heat units) required to bring the crop to maturity. At present some varieties will mature with as few as 2400 heat units. Soybean is sensitive to photoperiod, and daylengths of about 12 h are needed for most cultivars. Some cultivars, adapted to temperate latitudes, are insensitive to daylength (Tindall 1983; Hume et al. 1985; Upfold and Olechowski 1988).


Propagation is by seeds. These are planted in warm soils and emerge in 4–14 days depending on temperature, moisture, and planting depth. When soybeans are grown in soil for the first time, inoculation with soybean Rhizobium bacteria is essential for high yields. With soils previously unused for soybeans, soil-applied granular inoculants produce more consistent nodulation and higher yields than seed-applied powders. If the soil forms a crust as a result of heavy rainfall, rotary hoeing or harrowing to break the crust helps seedling emergence and also reduces competition from weeds (Upfold and Olechowski 1988).

Harvest and storage

Commercial soybeans are direct-combined, preferably with a combine equipped with a floating flexible cutterbar and automatic header control. Soybeans are harvested when seed moisture is below 20%. If seed moisture is below 12%, harvest losses and damage result from shattering (Upfold and Olechowski 1988). In Taiwan, studies of commercial storage of vegetable soybeans has shown that the young pods are best stored at 0°C in polyethylene

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bags containing an ethylene absorbant. Under these conditions the food can store for 4 weeks with minimal deterioration (Tsay and Sheu 1991). For home use, the young pods can be consumed green before the seeds are well developed. Soybeans can also be collected for shelling when they are fully formed in the pods but still green. Pods can be allowed to turn brown and the dried seeds collected and stored in airtight containers for winter use (Harrington 1978). Commercial storage of seeds requires seed moisture content between 12 and 14%. Seeds will not overwinter if moisture content is above 14%. Seed moisture of 12–13% allows storage for 2–3 years, but germination begins to decrease after 1 year. Storage bins are used both to store and to reduce soil moisture. Air circulation is critical because during cool periods the air near the outside cools and sinks, forcing warmer internal air to rise. This movement results in moisture content reaching 16–17% near the top centre, which leads to deterioration of bean quality. Seed moisture can be reduced by using air heated to 38°C with relative humidity of 40–50%. Unheated air is also used if the temperature is above 15°C with relative humidity below 70% (Upfold and Olechowski 1988). Example cultivars

Fiskeby V matures in a short growing season (70 days) and is low in the antitrypsin factor that interferes with the digestion of uncooked soy protein. This variety can be eaten raw in small amounts (Halpin 1978). Thousands of cultivars of the soybean are available, many specifically selected for producing forage, industrial oil, vegatable beans, and sprouts. Cultivars suitable for use as a vegetable are different from those used as forage or for obtaining oil. Hume et al. (1985) discussed soybean breeding and listed institutions in various countries conserving soybean germplasm. Facciola (1990) provided an extensive description of classes and cultivars available in the United States.

Additional notes Soybeans are used in food for diabetics because of the low starch content. Soybean oil, high in unsaturated fatty acid, is recommended to combat hypercholesteremia (dangerous levels of cholesterol deposition). Soybean contains high amounts of lecithin, reported to be a potent vasodepressor (Duke 1981); that is, it dilates blood vessels. Curiosities

Soybeans have been used in ancient Chinese folk medicine as a specific remedy for proper funtioning of the bowels, heart, kidney, liver, and stomach (Harrington 1978).

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The soybean was considered to be one of the five sacred grains essential to the existence of ancient Chinese civilization. The others were the cereals rice, wheat, barley, and millet. During the Second World War, soy flour was used extensively by the allied armies in field camps, and soybean was commonly called the “Wonder Bean” and the “Miracle Bean.” The phenomenal expansion of soybean cultivation in the Western World, beginning in the 1930s, earned it the label “Cinderella Crop.”

Problems and potential Soybeans are subject to a variety of disease and insect pathogens (Martens et al. 1984). Of particular concern are occurrences of soybean cyst nematodes, which damage the roots (Upfold and Olechowski 1988). Diseases of soybeans in Canada are discussed by Martens et al. (1988). Commercial soybean production has potential for growth. Soybeans are being used increasingly as animal and human food in Canada. In Canada, no estimate seems available on the value and production of tofu (soybean curd). The use of immature pods and shelled green seeds as a fresh vegetable seems restricted to home usage in this country.

Selected references Hackney 1990; Halpin 1978; Harrington 1978; Duke 1981; Hume et al. 1985; Hymowitz and Singh 1987; Upfold and Olechowski 1988; Shanmugasundaram 1991; Singh and Singh 1992.

Helianthus Jerusalem artichoke Compositae (Asteraceae) Sunflower family Composées, famille de la marguerite

Genus notes The generic delimitation of the New World genus Helianthus is somewhat difficult, as it is closely related to several other New World genera. Depending on authority, it includes about 70 to more than 150 annual or perennial coarse herbs. Several species are grown as flowering ornamentals. Helianthus annuus L., common sunflower, is cultivated in many parts of the world for its edible seeds used as food by humans and birds, and as an important source of oil. Curiously, one of the first uses of sunflowers when brought to Europe from the New World in the 16th century seems to have been consumption of the petioles and young flowers as vegetable delicacies. Another species, H. tuberosus, Jerusalem artichoke, is grown in vegetable gardens for its edible tubers. The sterile hybrid between the sunflower and the Jerusalem artichoke has been termed the sunchoke. This perennial produces abundant edible tubers and is much more vigorous than either of its parents. However, it has not been exploited as a cultivated crop with much success. The name sunchoke is now much more commonly used as an alternative commercial name to the Jerusalem artichoke.

Names Scientific (Latin) name: Helianthus tuberosus L. English common name: Jerusalem artichoke Also: sunchoke, girasole French common name: topinambour (m)

Description and taxonomy Jerusalem artichoke is a stout perennial that overwinters by its tubers. In wild plants the tubers are slender, usually enlarged at their tips, and commonly red-skinned. In domesticated forms the tubers are notably thicker, crisp-fleshed (like an apple), whitish or yellowish, sometimes tinged with pink, and sometimes purple- or red-skinned. Shape varies from clublike to oval and spherical, with short knobby branches present (this knobbiness is often less apparent in domesticated forms as compared with wild forms). The Jerusalem artichoke has been described as resembling a knobby, new potato in appearance and size. The “knobs” are buds, comparable to the “eyes” of potatoes. In

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many of the cultivars, the tubers are 5–8 cm across and up to 10 cm long. Jerusalem artichoke is native to the eastern and southern United States and tropical America. According to Scoggan (1978–1979), plants found growing “wild” in Canada are all garden escapes that have persisted after cultivation. Certainly old stands of Jerusalem artichoke can become weedy. True wild forms found in the United States and tropical America differ little from cultivated forms except for smaller tubers. An accepted taxonomic separation of wild and domesticated forms has not been established, although cultivars have been bred and can be distinguished from wild plants. Jerusalem artichoke was reported by Samuel de Champlain to have been cultivated by native Americans in what is now Massachusetts, in 1605. The tubers were collected primarily from wild plants, although the first tubers to reach Europe were slightly larger than those of wild plants, indicating that some selection had probably taken place in the New World. Some tubers were taken back to France and were temporarily popular as pomme du Canada (Canada apple) or batatas du Canada (Canada potato). Another early name was the American artichoke. The name artichoke was used by Champlain because he thought that the flavor resembled that of globe artichoke, Cynara scolymus L. (described earlier). The globe artichoke, often referred to simply as artichoke, is also a member of the sunflower family, but the portion harvested is the immature flower head, which is cooked as a vegetable. The “Jerusalem” in Jerusalem artichoke may be a corruption of Ter Neusen (Netherlands), the original source of the tubers to England (Simmonds 1976; Halpin 1978). (Another interpretation is that “Jerusalem is derived from ”girasole," an early Italian word for sunflower.) Authors have repeatedly taken delight in pointing out that the Jerusalem artichoke is neither an artichoke nor from Jerusalem.

Uses As a specialty vegetable, Jerusalem artichoke tubers are consumed much like potatoes—boiled, baked, fried, and incorporated into soups and stews. They may also be served raw in salads. Although quite distinctive in taste from potatoes, the Jerusalem artichoke is frequently compared with this much more familiar food, which has contributed to its lack of popularity. The sugar inulin is the main storage carbohydrate in the tubers, not starch as in many other root crops. The lack of starch and the presence of inulin has resulted in the recommendation that the Jerusalem artichoke is a suitable food for diabetics, that may be consumed in moderate amounts without serious increase in blood glucose. Because inulin cannot be digested by humans, caloric intake

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is reduced, while volume intake results in some alleviation of hunger. Therefore, the Jerusalem artichoke may also be of value as a low-calorie food. Hydrolysis of inulin produces fructose, a sugar that is 1.5–1.7 times as sweet as sucrose and so requires a smaller caloric consumption to achieve a given level of sweetness. There may be commercial possibilities for production of fructose from Jerusalem artichoke. According to Richardson (1990), inulin-containing vegetables like Jerusalem artichoke can give some people gas if eaten in large quantities. Baker et al. (1990) discussed the economic competitiveness of Jerusalem artichoke as a feedstock for ethanol production. Both the tops and tubers can be used for ethanol. Studies in Quebec and western Canada showed that the latter had a large cost advantage in producing tops and a small advantage for tuber production. Jerusalem artichoke can be a source of ethanol that is competitive with corn, but neither is currently competitive with gasoline. Caserta and Cervigni (1991) found that the tops accumulated sugars until late summer, and then the sugars were transferred to the developing tubers. Jerusalem artichoke could be grown as a perennial sugar crop, harvested in late summer and overwintered as tubers left in the ground. Jerusalem artichoke can also be used as a coffee substitute or coffee additive. Freshly dug tubers are washed, cut into small slices, and roasted in a slow oven at 120°C for 1–2 h, until they become dark brown and crisp. The pieces are ground and stored in a closed container. Because of the inulin content, the resultant drink has a sweeter flavor than regular coffee (Turner and Szczawinski 1978). Jerusalem artichoke is useful as animal feed in a variety of ways. Yields of top growth approaching 5 t/ha have been observed in Canada, and the tops may be used to make a silage of low to moderate grade. The pulp remaining from the tubers after inulin has been extracted commercially also makes a useful livestock feed. When grown to feed swine, the tubers may be left in the ground and the pigs turned loose on the plot to root out the tubers. Among other minor uses of Jerusalem artichoke are production of flour, a beerlike beverage from the tubers, the chemical 5-hydroxy-methyl-furfural, and processing of the tops into paper, fiberboard, charcoal, and methyl alcohol. Example recipes

Arti-health coffee (Turner and Szczawinski 1978) Broiled Jerusalem artichokes (Szczawinski and Turner 1978) Creamy Jerusalem artichoke soup with hazelnut butter (Schneider 1986) Gibelotte of rabbit and chokes (Morash 1982) Gratin of Jerusalem artichoke (Schneider 1986) Jerusalem artichoke au gratin (Organ 1960) Jerusalem artichoke cheese soup (Morash 1982) Jerusalem artichoke chiffon pie (Morash 1982) Jerusalem artichoke chowder (Szczawinski and Turner 1978) Jerusalem artichoke coffee (Turner and Szczawinski 1978) Jerusalem artichoke salad (Richardson 1990)

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Jerusalem artichoke winter salad (Szczawinski and Turner 1978) Jerusalem artichokes with Hollandaise (Morash 1982) Lacy Jerusalem artichoke pancakes (Morash 1982) Stir-fry chokes and broccoli (Morash 1982) Pickled Jerusalem artichokes (Richardson 1990)

Importance In Canada the main use of Jerusalem artichoke is for production of flour that is reportedly a nonfattening substitute for wheat flour. There is interest in using the aboveground parts as a silage, which produces acceptable yields and quality (Hergert 1991). Jerusalem artichoke cannot be grown economically in Canada at present as a source of alcohol (Baker et al. 1990). As a human food crop, Jerusalem artichoke is occasionally grown for local markets (at least in Ontario and Saskatchewan) and in home gardens. Yields of tubers in Canada have ranged up to 75 t/ha when grown on highly productive soils in southern Ontario. Yields of 30–40 t/ha are more common. The tubers can provide 2.7–5 t/ha of carbohydrates (Hergert 1991).


Jerusalem artichoke is commonly thought to grow well in marginal soils. However, Agriculture and Agri-Food Canada regional tests (Hergert 1991) have shown that the crop does not produce abundantly in poorly drained soils or in northern areas. It also has yielded poorly on peat soils in Quebec. Tubers planted in loose sandy loam soil perform satisfactorily, and loose soil allows for easier harvest (Hergert 1991).

Climate

Jerusalem artichoke is a hardy perennial, well adapted to the Canadian climate. Plants take about 130 days to mature, making it one of the long-season crops (Baker et al. 1990). Irrigation is required during dry periods. Laberge and Sackston (1987) found that early and mid-season cultivars were better adapted around Ottawa and Montreal than a late-season cultivar.


Although Jerusalem artichoke overwinters as tubers in the ground, it is commonly grown as an annual from tuber cuttings. Tubers intended for replanting can be stored indoors for several months at 0°C and a relative humidity of 90–95%. They are then replanted in the spring, either as whole tubers or as pieces cut to include an “eye.” Hilling is an effective form of weed control until plants begin to form a canopy that further discourages weed growth (Hergert 1991).

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Harvest and storage

Jerusalem artichoke tubers are harvested using a potato harvester. Some modifications to the harvesters are required to dig up the tubers. Tubers that have overwintered in the ground can be used as food the following spring if dug before they start to grow. The tubers are prone to shrivelling because of their thin skin. For short-term storage, they are best kept in a refrigerator. For long-term storage, tubers are maintained in moist sand in a cool place. They will survive until spring if kept moist (Halpin 1978). Agriculture and Agri-Food Canada’s Morden Research Station, in Manitoba, has demonstrated a liquid medium suitable for storage of the tubers. Storage is difficult because of the exceedingly quick losses caused by a fungus of the genus Sclerotinia, which can spread quickly through a pile of tubers. The French cultivar Fuseau 66 has a netted surface. Netted tubers have a raised, netlike surface that reduces the threat of spread of disease pathogens in storage because less of the tuber surface is in contact with adjacent tubers (Hergert 1991). Jerusalem artichoke tops destined for use as a sugar source are harvested like hay, using small or large balers (Baker et al. 1990; Halpin 1978). If the tops are to be removed prior to harvest of the tubers, care must be taken to keep the wheels of the harvester in the furrows between the rows, as the tubers are susceptible to damage from the wheel weight (Hergert 1991).

Example cultivars

Laberge and Sackston (1987) discussed the performance of commercial cultivars selected for harvest time, including Columbia (early season), Challenger (mid season), and Oregon White (late season). Morden Research Station has been active in selecting cultivars suitable for Canadian production. In addition to those already mentioned, Sunroot 1000 is similar to Challenger but has red-skinned tubers. Fuseau 66, the only variety known to produce a netted tuber, has higher than normal amounts of carbohydrates but, in Canada, apparently will only mature in southern Ontario (Hergert 1991). Some Canadian garden catalogs simply sell tubers under the name “Jerusalem artichoke.”


The French (rarely also English) name for the Jerusalem artichoke, topinambour, was first used in France to arouse interest in the newly introduced vegetable, following the sensation that was generated by the exhibition of six natives from the Topinambuous tribe of Brazil. Raw Jerusalem artichoke has a nutlike flavor. However, because of differences in body chemistry such as those that prevent some people from detecting bitterness in certain foods, not everyone can appreciate the nutty taste. It has been reported that Jerusalem artichoke, when grown on nematode-infested soils, can result in a reduction of 45% in the nematode population (Kay 1973).

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A species related to Jerusalem artichoke has one of the least pronounceable of scientific names: Helianthus szyszylowiczii Hieronymus. When swine have been fed Jerusalem artichoke, the smell of their manure is noticeably reduced (Hergert 1991; Farnworth 1992). In the early 1980s, in Minnesota, Jerusalem artichoke was the basis of a get-rich-quick, pyramiding scheme, promising up to $15 000 per hectare (Amato 1993). It seemed attractive, because it could be used as a fuel, a feed, a food, and a sugar crop. Unfortunately there was no market for the new “wonder crop,” and about 500 farmers lost about $20 million. The mastermind behind the scheme was fined $20 000 and sentenced to 1 year in jail (Paarlberg 1990).

Problems and potential Jerusalem artichoke is subject to a variety of disease organisms, including powdery mildew, sclerotinia wilt, stalk and tuber rot, and bacterial pathogens. Sunflower stem maggot, Strauzia longipennis (Weid.), has caused damage by tunneling in the stem pith. Storage losses from sclerotinia rot have been particularly troubling. Among the disadvantages attributed to the Jerusalem artichoke are the following: perishable nature of the tuber, due in part to its thin, easily damaged skin occasional digestive disturbances high cost of harvesting difficulty in removing all tubers from the soil with the result that the plant, which is very aggressive, becomes a noxious weed in some areas Among its advantages are the following: its potentially high yields relative freedom from insect pests cold tolerance diverse possible uses that may receive wider economic exploitation in the future Jerusalem artichoke tubers destined for the fresh market will likely remain as an occasional crop in local markets and home gardens. The species is genetically variable, however, so it does have potential to be improved by breeding (Seiler 1993). This crop also has potential for ethanol production if prices of gasoline were to rise appreciably (Loughton et al. 1991).

Selected references Chubey and Dorrell 1983; Laberge and Sackston 1987; Baker et al. 1990; Hergert 1991.

Humulus Hop Cannabaceae Hemp family Cannabacées, famille du chanvre

Genus notes Humulus has three species of wind-pollinated, herbaceous vines, indigenous in northern temperate areas, including one annual and two perennials (Small 1978a). The vegetable use of Humulus lupulus is examined in this chapter, while the beverage use is discussed in Small (1997).

Names Scientific (Latin) name: Humulus lupulus L. English common name: hop Also: English hop, hops [The singular “hop” is best reserved for the plant, and the plural “hops” for the cones produced by the hop plant.] French common name: houblon (m)

Description and taxonomy Hop is a high-climbing perennial vine, in cultivation exceeding 6 m (the average height of commercial trellises in North America), and sometimes extending more than 10 m. The annual, above-ground stem is killed by frost each year, and regrowth occurs each season from perennial underground rhizomes. The perennial crown becomes woody with age, with heavy, rough, dark brown bark. Rhizomes produced from the crown possess numerous buds and are used for propagation. Hop plants grow rapidly, sometimes as Branch with cones (hops) much as 15–30 cm in 24 h. Humulus lupulus is one of the few cultivated plants with separate sexes, i.e., some plants have male flowers, others female flowers. The female plants produce the commercially valuable hops (the cones or fruit-clusters) and also have greater ornamental value than the male plants. Consequently, the latter are generally discarded as soon as

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they can be recognized. In hop plantations, male plants are regarded as a nuisance because their pollen fertilizes the female flowers and prevents the formation of the valuable “seedless hops” that are increasingly preferred in commerce. Like potatoes, apples, and some other crops, hop is propagated primarily vegetatively rather than by seeds. More than a hundred cultivars have been named, each essentially a clone (a genetically uniform line); many have been reproduced for centuries. The cultivars have not been classified into one group, separate from the wild groups, as has been done for many other plants treated in this book. There are five varieties of wild hop (Small 1978a) as follows: var. lupulus, the only wild hop of Europe, extending into Asia var. cordifolius (Miquel) Maximowicz, the only wild hop of Japan var. neomexicanus Nelson & Cockerell, the predominant wild hop in the western Cordillera of North America, from Mexico to British Columbia var. pubescens E. Small, found only in the Midwest of the United States var. lupuloides E. Small, in eastern North America, including most wild hops from the Prairie Provinces to the eastern seaboard of Canada In Canada, and indeed in much of North America, the European variety, var. lupulus, is found as an escaped plant from past use in brewing, or as a persisting ornamental around abandoned homesteads. The vegetable use of hop has always been limited but nevertheless traces to antiquity. One of the first authentic references to hop was by the 1st-century Roman author Pliny, who noted in his Natural history that the plant was served as an appetizer and as a salad green (Grieve 1978). Also, in classical Rome young shoots of hop were harvested in the spring and consumed like asparagus (Grieve 1978). Wild hop has been used throughout recorded history for culinary, medicinal, and household purposes, although it is chiefly as a brewing ingredient that it is well known. However, the early history of the cultivated hop is obscure. Beer was an important beverage throughout the ancient world. Herbs and spices were often added to beer to improve flavor or keeping qualities, and it seems that ancient civilizations used hops for this purpose. The first unequivocal evidence for cultivation of hop comes from 9th-century Bavaria, where it appears that a tradition of using hops in beer has continued for perhaps a millenium. During the Middle Ages many monasteries were famous for their hopped beers. The brewing trade developed to a highly refined art, with beer being consumed at breakfast, dinner, and supper. Hops were not introduced into England until the close of the 15th century. They were brought to North America and grown in the early 17th century. By the middle of the 19th century, New England and New York produced the bulk of the hops in the New World. However, by the early 20th century, the Pacific Coast became the leading hop-producing area in North America. In the 1920s, hop growing in New York was practically wiped out by

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powdery mildew and by Prohibition. Similarly in Canada, commercial hop growing was phased out in the east by the end of the Second World War and became established in British Columbia. The wild European variety, var. lupulus, occupies a central role in the evolution of cultivars of hop. Cultivars were selected first from this variety simply because of the long history of usage of the hop in Europe. It was these European cultivars that accompanied the art of brewing to the New World in the 17th century, and to Japan, apparently in 1876. However, both in Japan and in North America, the local wild hops hybridized with the imported European hop, to produce unique Japanese and European cultivars (Small 1980, 1981). Brewers have long recognized that North American cultivars have a higher content of the important brewing constituents, the alpha acids, and produce beer of stronger aroma.

Uses Besides its primary use as a brewing ingredient, hop has some limited use either cooked as a vegetable or raw as a component of mixed salads. Young shoots (6–10 cm long) are often consumed as a potherb, like asparagus. These spears can be boiled for 2–3 min and then boiled in a change of water until tender. When steamed for 5 min and served with melted butter or cheese sauce, the shoots taste much like asparagus. In hop-producing areas of Europe, blanched hop spears are sometimes served in fine restaurants. Hop has another culinary use. Before yeast cakes became widely available in stores, yeast for bread making was prepared by culturing wild yeast in a decoction of hops and water. Some of this liquid was mixed with bread dough, adding flavor to the bread and apparently preventing the yeast from spoiling by virtue of the antiseptic properties. Kirk (1975) stated that the seeds and female flowers of hop were used by some North American Indian groups in making bread. Still another culinary use is the preparation of hop tea, prepared as an infusion of the leaves and cones (Grieve 1978). Also, of course, hops are a chief constituent of beers, which in the past have often been produced in kitchens and not just in specialized breweries. The oil and resin of hops have contributed to a reputation, greatly exaggerated, for valuable medicinal properties, and hops have a long history of use in medicine. However, the resin is bacteriostatic (against gram-positive organisms), which may lend some credibility to the former use of hop in treating certain types of epidermal sores and irritations. Edwardson (1952) has reviewed many of the ways hop has been used. The stems, which contain considerable fiber, have been used in making paper and twine. The inflorescences and leaves of hop yield a yellow dye. Humulus lupulus is a popular garden ornamental, and some cultivars have been selected for their decorative qualities.

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Example recipes

Hop shoots à la crème (Buishand et al. 1986) Hop shoots with poached eggs (Buishand et al. 1986)

Because hop spears can be used like asparagus spears, consult the section on Asparagus for additional recipes.

Importance Hops are a specialty or minor crop wherever they are grown. Of the two dozen countries that raise substantial commercial crops of hops, Canada occupies an intermediate position. World centres of hop production include England, the former Czechoslovakia, Germany, the former Yugoslavia, and the United States. Almost all the commercial hop crop of Canada is raised in the Fraser Valley of British Columbia. The domestic supply is insufficient for Canada’s requirements, so large quantities of hops are imported. In the normal course of raising hops commercially, rhizomes are regularly excavated to provide divisions for regenerating the hopyard (see “Propagation and cultivation,” below). With many rhizomes on hand, these are available for production of “spears” for the vegetable trade. Hop shoots, a popular vegetable in Europe during the 18th and 19th centuries, seem to be becoming fashionable again in the Old World (Buishand et al. 1986). In Europe, especially in Belgium, Germany, France, and Britain, hop rhizomes are sometimes forced in special houses during the winter to produce blanched spears (Buishand et al. 1986; Eckel and Fritz 1990). Statistics for production of hop as a vegetable in various countries, including Canada, are unavailable. In Canada, there is no commercial production of hop spears at present.


While hop grows in a wide variety of soils, it performs best in rich, alluvial or deep sandy or gravelly loams. In eastern Canada, well-drained soils considerably reduce winter-killing by frost heaving of the roots, although in mild areas of British Columbia the plants can be grown on somewhat heavier soils.

Climate

Hops are adapted to a wide range of temperate climates. In North America, dry inland valleys of the Pacific Coast provide hospitable climates. The hop plant survives considerable cold and indeed needs a dormant period initiated by frost before resuming growth. Good snow cover can reduce winterkill in very cold regions. Considerable moisture is required, but well-drained soils are necessary.


Although hops can be grown from seeds, they are generally propagated vegetatively by “root” (rhizome) cuttings. Hop plants live for up to 50 years, but commercial growers usually replace 1–10% of

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the plants annually, and, in practice, growers often renew their plantings at intervals of 6–15 years. The most prominent feature of a hopyard is the huge trellis or supporting structure provided for the annual vines to climb upon. The trellis is usually constructed from heavy wire strung across wooden poles placed in a regular pattern to facilitate mechanical picking of the cones. The home gardener can grow hop for culinary purposes in the traditional manner (Organ 1960). Young root cuttings are established, and some shoots are harvested in the spring. During the remainder of the season, the plants are allowed to grow, but the fruit clusters (cones) are removed regularly so that the plants channel their energy into the rhizomes. This treatment results in the plants producing many shoots the following season. Blanching (preventing light from reaching the shoots so that they do not develop green color) can be Rhizome (bottom), achieved by covering the shoots with earth. This spears (top) process produces the most tender spears. Harvest and storage

When grown for hops, the vines are cut and the cones are removed and dried usually in forced-draft hot-air kilns (removing 80% of the weight). They are then packed for storage and delivery. In the United States and Canada, picking by machine has proven 10–20 times as efficient as hand labor. In North America most hops are pressed into 91-kg (200-lb) packages and wrapped in burlap. Hops deteriorate rapidly at room temperature, so they are normally refrigerated and used promptly in brewing, between 4 and 20 months after harvest. Hop shoots to be used as a potherb are sometimes harvested from wild plants growing in nature. Inasmuch as toxic plants can grow among hop shoots, and identification of young shoots can be difficult, such an exercise should only be carried out with experienced guidance. Although rhizomes keep well when left intact in the ground, once spears are picked they should be used as soon as possible, within a few days, because they store poorly.

Example cultivars

At present, ornamental and brewing cultivars are available, but not cultivars specifically bred for production of vegetable spears. The young shoots of any available cultivar, and indeed of transplanted wild plants, are suitable. Although considered a specialty item, root cuttings, potted vines, and seeds are available from various sources in Canada and the United States. Eckel and Fritz (1990) compared three brewing cultivars, and found that the cultivar Tettnanger Frühhopfen showed about 25% higher yield of spears and much better shoot quality than the varieties Northern Brewer and Orion.

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The genus name Humulus is derived from the Latin humus, soil, an allusion to their soil-hugging habit if these vines are not supported. The species name H. lupulus is derived from the Latin lupus and its diminutive lupulus, a wolf; in ancient Rome, hop was called lupulus salictarius—a “wolf among willows,” suggesting that when it grew among willows it was as destructive as a wolf among sheep. Three saints are listed as patrons of brewing: St. Augustine of Hippo, author of Confessions and most influential of the early Christian philosophers; St. Nicholas of Myra, better known as Santa Claus; and St. Luke, the Evangelist. A longstanding belief, at least a millenium in age and entertained to the present, is that hops have extraordinarily powerful soporific qualities. For this reason, hops were commonly planted outside bedroom windows, and hops were (and still are) used to stuff pillows. The sedative value of hops has also been said to be a “cure for uncontrolled sexual desires and a quarrelsome nature.” Women have been unusually prominent in brewing throughout history. In ancient Babylonia, women brewers were also temple priestesses. During the medieval period, brewers were women, who were often known as “ale wives.” Ladies-in-waiting at the court of Henry VIII were allowed a gallon of beer for breakfast. “Ale conners” were officials in Old England who were responsible for overseeing ale quality (Shakespeare’s father was an ale conner). A quaint custom of testing the quality of brew involved pouring some on a bench and sitting in the puddle wearing leather breeches for about half an hour. If sugar remained in the ale (indicating incomplete fermentation), the breeches would stick to the bench. The Pilgrim Fathers, who landed at Plymouth Rock instead of farther south as they had planned, did so at least partly because of lack of beer. One of the Mayflower’s passengers, in an entry dated 19 Dec. 1620, wrote: “We could not take time for further search or consideration, our victuals being much spent, especially our beer.” The first commercial brewery in Canada was founded in Quebec in about 1668 by the Intendant Jean Talon, to control the intemperate use of stronger drink. In parts of Europe, the presence of male plants in hopyards is forbidden by law. The patent office of the United States once granted a patent to a man who claimed to have “invented” the hop’s habit of winding from left to right (i.e., circling clockwise, viewed so that the twining stem is growing towards the observer). Many other kinds of vines, runner beans for example, climb anticlockwise. It is a popular misconception that American beers generally have less alcohol than Canadian beers. The error arises because

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Canadian alcohol content is reported by volume, whereas American is by weight. Although there are about a dozen so-called “national” brews in Canada, more than 100 additional brands are brewed to the individual taste of particular regions. It is ironic that the closest relative of the genus Humulus is Cannabis, the marihuana plant. Both genera possess numerous small secretory glands producing a resin, but while the aliphatic acids of the hop plant resin provide flavor for legal intoxicants, the intoxicating tetrahydrocannabinol of the marihuana plant is illegal.

Problems and potential Because hops are a well-established agricultural commodity, albeit for a purpose other than for use as a vegetable, current hop agriculture offers the best possibilities of harvesting some of the crop in the spring for fresh and canned hop shoots for the commercial trade. Also, as noted earlier, hops can be forced out of season to produce spears for the fresh market. Certainly these are interesting possibilities for crop diversification. An unusual feature of the hop as an agricultural commodity results from its complete economic dependence on the brewery industry. Because of the stability of the brewery industry, whose output is highly predictable, there is no elasticity in consumable annual crop. As a result, small deviations from market demand can cause disastrously low prices in the case of oversupply, or extremely high prices in the case of relatively small shortages. Hops are an extremely light commodity in relation to value and are easily transported long distances without loss of brewing qualities. Moreover, in recent years hop extracts and compressed hop pellets have decreased transportation costs considerably. This factor has contributed to the centralization of hop farming, and the creation of a large international trade in hops. Hop farming is highly specialized and requires much capital investment. It is very labor intensive. These considerations make the traditional family farm operation inadvisable for hop growing, which is increasingly an “agribusiness” venture. It would seem that the raising of hop as a vegetable, because it is economically tied to large hopyards, might also deter the small operator. Although some hopyards might provide spare rhizomes to small specialty vegetable producers, some hop companies, to guard the exclusivity of certain brands of hops, will not sell their rhizomes.

Selected references Edwardson 1952; Small 1978a, 1980, 1981, 1997; Eckel and Fritz 1990.

Ipomoea Convolvulaceae Morning-glory family Convolvulacées, famille du liseron

Genus notes The genus Ipomoea may have more than 500 species of twining, prostrate or erect, annual or perennial herbs, some of which become shrubby. They are native to tropical and warm temperate regions of the world. Many species are used as ornamentals, either for their flowers or as coverings on fences or trellises. Some are employed for their hallucinogenic properties, and numerous species are considered to have medicinal uses. A few Mexican species, including I. purga (Wender.) Hayne, known as jalap, yield purgative resins from the roots. Two species are used as vegetables, I. aquatica for its edible leaves and shoots, and I. batatas for its edible roots. Both are discussed below.

Water spinach

Names Scientific (Latin) name: Ipomoea aquatica Forsk. English common name: water spinach Also: kang kong, kancon, green engtsai, Chinese convolvulus, swamp cabbage, ung choy French common name: patate aquatique(f)

Description and taxonomy Water spinach, a native of southeast Asia and India, was cultivated as a vegetable in Asia as long ago as the Chin Dynasty, about 300 A.D. Water spinach is currently grown widely in southeast Asia, Australia, and some parts of Africa. It has been introduced to Hawaii, Brazil, Central America, and several Caribbean Islands. Two forms are cultivated, as follows: aquatic form (sometimes called var. aquatica) upland form (sometimes called var. reptans) The aquatic form is a short-lived, herbaceous perennial that grows in or near water as a semi-aquatic plant. The leaves are arrow-shaped with long petioles, and the stems are hollow. The flowers are white or

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pink. The plant lies prostrate or floats. It is cultivated in the southern part of India and southeast Asia. The upland form is an annual herb cultivated as a vegetable on dry or marshy land. It has narrower leaves than the aquatic variety and the stems are generally upright. It is an important market vegetable in Malaysia, Indonesia, and other southeast Asian countries (Tindall 1983; Jain et al. 1987). The scientific names used for I. aquatica require study. Neither varietal epithet mentioned above (aquatica, reptans) appears to have been validly published. Moreover, the species name I. sagittaefolia Burman fil. may be the correct name, rather than I. aquatica (Hochreutiner 1934, p. 186). The wild form is not separated taxonomically from the cultivated var. aquatica. Domestication of the wild form took place in tropical Asia, possibly India (Tindall 1983).

Uses Water spinach leaves, considered Vietnam’s national vegetable, are used in the tropics as a cooked vegetable. This vegetable has a high iron content and is sometimes fed to patients suffering from anemia. It is also a valuable livestock fodder and is fed to cattle and swine in the Philippines, Malaysia and Fiji (Schery 1972; Bailey and Bailey 1976; Tindall 1983; Jain et al. 1987). Water spinach is also used as fish food. Example recipe

Indonesian water spinach (Buishand et al. 1986)

Importance Water spinach is a home garden curiosity in Canada. It is a vegetable used mainly in southeast Asia, Malaysia, and India. This plant supplies about 15% of the local vegetable output in Hong Kong during the summer season (Schery 1972). In the United States, the species is cultivated as a vegetable by Asian immigrants for personal use and for sale in oriental food markets.


Water spinach is adapted to a wide range of soil conditions. Moist clay soils high in organic matter are ideal.

Climate

This tropical plant grows best when mean temperatures are above 25°C, with growth retarded below 10°C (Tindall 1983; Yamaguchi 1983).


Water spinach is propagated by seeds or rooted cuttings. In the tropics, the upland form is grown in moist-soil culture on raised beds, with furrows between the beds flooded soon after seeds are sown or cuttings transplanted. Frequent heavy irrigation is necessary for high-quality shoots. The aquatic form is transplanted into puddled soil,

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similar to rice in paddies. The land is flooded to 3–5 cm deep, and the water must be kept flowing (Tindall 1983; Yamaguchi 1983). Harvest and storage

The aquatic and upland forms are harvested by hand-picking at about 1 month after transplanting of cuttings; the shoots are cut above ground level. Removal of the main shoot stimulates side-shoot production. The land form can be harvested about 2 months after sowing of seeds. Entire plants can be pulled, washed, and bundled for market. More than one harvest is possible if shoots are cut to ground level. The leaves wilt very easily and, in the tropics, they are either wrapped in a banana leaf with open ends or packed in polythene-lined crates and immediately marketed (Tindall 1983). Tests have produced dry weight of 20 000 kg/ha in 8 months in India, and annual fresh weight yields of 70 000–100 000 kg/ha have been reported (Jain et al. 1987).

Example cultivars

Some Canadian seed catalogs offer water spinach. Bettencourt and Konopka (1990) listed institutions in various countries conserving water spinach germplasm.

Additional notes Consumption of water spinach has been documented to be protective against high blood pressure and nosebleeds. Water spinach is also a rich source of carotenoids that have been implicated in prevention of skin tumors. Chen and Han (1990) studied the effects of cooking on carotenoid content. They found that raw water spinach had the highest concentrations, followed by material cooked by steam or by microwave. Conventional water boiling produced the lowest concentration of carotenoids. Ipomoea aquatica has been listed by the U.S. Department of Agriculture as a potentially noxious weed in the United States (Tucker and Maciarello 1987), although it is easily obtained through American seed catalogs. Curiosity

Water spinach takes up organic and inorganic heavy metals from waste water, and so can be used in waste water treatment in the tropics (Jain et al. 1987).

Problems and potential Water spinach may remain an oddity of Canadian home gardens, because this tropical plant is so poorly adapted for outdoor Canadian conditions. It will be of most interest to immigrants from tropical climes where the plant is employed as a vegetable. Water celery (Oenanthe javanicum (Blume) D.C.) is a popular Asian flavoring herb that, like water spinach, lends itself to hydroponic culture (see Small (1997) for additional information). Water celery has been cultivated in Ontario by immigrants of Asian origin and has been grown hydroponically in greenhouses in Ontario to a minor extent. It may well be that


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water spinach also has some potential for greenhouse culture in Canada. Water spinach infestations have occurred in Florida, where great efforts are being made to prevent establishment of the species. However, many believe that it is only a matter of time. Water spinach is considered Florida’s most problematic non-naturalized noxious weed species. It grows prolifically in the state, and as a vine may climb taller than 21 m. Fortunately for Canada, this plant is confined to the tropics and subtropics because it is susceptible to frosts and grows poorly where mean temperatures are below 24°C.

Selected reference Tindall 1983.

Sweet potato

Names Scientific (Latin) name: Ipomoea batatas (L.) Lam. English common name: sweet potato [Also inappropriately called “yam,” a term better reserved for species of the genus Dioscorea, some of which produce edible tubers similar to the sweet potato. Yams are much starchier and generally not nearly as tasty as sweet potatoes, and require hotter growing conditions. In the United States, the terms yam and sweet potato are generally used interchangeably, and to prevent confusion the U.S. Department of Agriculture requires that the label “yam” always be accompanied by “sweet potato” when the latter is marketed in large quantities.] French common name: patate (f) Also: patate douce

Description and taxonomy Sweet potato is a herbaceous vine or bushy perennial, cultivated for its edible roots. The edible portion is a fleshy storage root, not a tuber (which develops from stem tissue) like the potato. Sweet potatoes do not have eyes (which are embryonic shoots that in “seed potatoes” grow into new plants), but they can develop adventitious buds on vines or cuttings, and these are useful for vegetative reproduction. Two important kinds of sweet potatoes are grown commercially. When cooked, one has a dry, mealy flesh; the

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other has a soft, moist, sugary consistency. The latter is the familiar type grown in North America (Purcell et al. 1989). Sweet potato originated in the Americas, but there is debate as to where it was domesticated (Austin 1987; Heiser 1990). Sweet potatoes have been dated from Peru at 10 000 B.C., although this vegetable may have been introduced from farther north. When Europeans first arrived in the New World, sweet potato was already widely used, and several cultivated forms were known. Living plants reached Spain about A.D. 1550. Some evidence exists that sweet potato was dispersed westward across the Pacific, perhaps by the Polynesians, before European exploration. It has been identified archaeologically in New Zealand from the 14th century; also the first Spaniards to reach the Solomon Islands, the Marianas, and the Philippines reported that it was cultivated there. Sweet potato was a major food source during the American Civil War (Nonnecke 1989). Wild forms of sweet potato have been reported from coastal Ecuador, Columbia, and Mexico. Two wild forms are recognized as follows: var. batatas has fruits that open spontaneously at maturity and lacks roots at most stem nodes var. apiculata (Martens & Galeotti) McDonald & Austin has indehiscent fruits and the propensity to develop roots at each node of the trailing stems (Austin 1987; McDonald and Austin 1990) Ipomoea batatas may have derived either from the Caribbean, now pantropical, I. tiliacea (Willd.) Choisy or from I. trifida G. Don, a Mexican species (Tindall 1983).

Uses The enlarged storage roots of sweet potato are commonly used as a vegetable. The leaves may also be eaten as a vegetable, although harvesting them is detrimental to growth of the storage roots during the short Canadian growing season (Villareal et al. 1985; Allan 1991). The storage roots are canned, frozen, or dehydrated and are also used as a source of starch or alcohol, as a dessert, and as animal fodder (Bouwkamp 1985; Midmore 1990). Example recipes

Boniatos and apple purée (Schneider 1986) Deep-fried sweet potato chips (Morash 1982) Stuffed baked boniatos (Schneider 1986) Sweet potato and chicken with fruit sauce (Morash 1982) Sweet potato bread (Morash 1982) Sweet potato casserole (Richardson 1990) Sweet potato soup (Buishand et al. 1986) Sweet potato waffles (Morash 1982) Sweet potato, lamb, and sausage stew (Morash 1982) Sweet potato–chocolate nut cake (Morash 1982) Sweet potato–lime chiffon pie (Morash 1982) Yams with ginger and dried apricots (Ornish 1990)


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Importance Nearly all sweet potatoes are grown in developing countries, about 80% in China alone. Since the early 1960s, sweet potato production has dropped sharply in developed countries (to about 6% of the world total) while increasing significantly in Africa. Total world production (average 1983–1985) was 114 185 000 t on 7 998 000 ha (Horton 1988). In Canada, sweet potato is commercially produced in limited quantities for local markets and is also grown in home gardens. It has been grown as an alternative crop by tobacco growers in southern Ontario (Opdecam 1991). In 1991, 7963 t of sweet potatoes were imported into Canada (Anonymous 1992a).


Sweet potatoes are tolerant of a wide range of soil types but do best in well-drained sandy loam or clay-loam soils. The crop is grown on mounds to avoid water-logging. The soil pH should range from 5.6 to 6.6.

Climate

Sweet potatoes require at least 120 frost-free days for optimum growth and are of limited commercial importance where mean summer temperatures are below 20°C. Little growth occurs if soil or air temperatures are below 16°C and irreversible damage results below 10°C. The plants require supplemental water during dry periods (Tindall 1983; Nonnecke 1989).


In temperate countries the storage roots are kept overwinter and, before sprouting, are subjected to 30°C and high humidity for 4 weeks. They are then “bedded” on raised beds, sometimes with added heat, to promote growth of sprouts, which are then used as transplants. Seeds are not used for reproduction because they produce many off-types. The plants are usually put on ridges or mounds, where warmer soil temperatures encourage growth (Purcell et al. 1989). In Canada the plants need as much warmth as they can get. Best performance in home gardens has been obtained by planting rooted cuttings on raised beds covered by clear plastic mulch. The storage roots develop most after mid August. Because of falling temperatures, the sweet potatoes should be dug up by mid September, or earlier if the soil cools below 10°C. Reproductive stock can be kept overwinter by saving blemish-free, small, fleshy roots, curing them (as described below), and storing them. Alternatively, cuttings can be taken from the plants in late summer, rooted in warm water, and then potted for the winter (Allan 1991).

Harvest and storage

Sweet potato storage roots continue to enlarge as long as growing conditions are suitable, ceasing growth when subjected to frost or soil

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temperatures below 13°C. Commercial sweet potatoes are dug out of the ground by plow and hand-graded. They must be handled gently to prevent bruising. Experimental use of a regular potato digger for harvest left the sweet potatoes in the ground, requiring hand-picking (Opdecam 1991). Some mechanical harvesters will separate the vine from the storage roots and even transfer them to pallet bins. Sweet potatoes not sold directly from the field are cured for 4–7 days at 30°C and 90% relative humidity. The curing is primarily to heal wounds, to prevent invasion of decay organisms. Curing also reduces moisture loss and increases the amount of starch conversion to sugar. Sweet potatoes have been cured in existing or modified tobacco kilns. After curing, sweet potatoes are best stored at 13–15°C and 50% humidity (Purcell et al. 1989). Example cultivars

There are several hundred sweet potato varieties, but only a few that are widespread commercially (Richardson 1990). Cuttings of Beauregard and Georgia Jet are available in Canada, the latter performing particularly well (Allan 1991). It has been tested by home gardeners in Ottawa, with yields per plant averaging 3.6 kg. In a test in Canada, Beauregard outperformed Jewel (Opdecam 1991). Sweet potato breeding was discussed by Jones et al. (1986). Genetic resources of sweet potato are kept at the International Potato Center, in Lima, Peru, as well as at some other gene resource centres in different countries (Bettencourt and Konopka 1990; Midmore 1990). Facciola (1990) provided an extensive description of cultivars available in the United States.

Additional notes Ipomoea roots produce chemicals that inhibit growth of other plants. Field studies have shown that the sweet potato cultivar Regal greatly reduced the growth of a common weed, yellow nut sedge (Cyperus esculentus L.). Sweet potato residues in soil also inhibited growth of several plants, including sweet potato cuttings (Harrison and Peterson 1991). Curiosity

German researchers have inserted an antisense gene into sweet potatoes that blocks the production of ADP-glucose pyrophosphorylase, an enzyme that converts sucrose to starch in the roots. The result is that the roots remain very sweet (Anonymous 1992f).

Problems and potential Sweet potato is subject to a variety of disease pathogens (Clark and Moyer 1988), although this susceptibility may not be of major importance in Canada because only small areas are planted.


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Sweet potato is a minor crop in Canada and is likely to remain so because it needs warmer, longer seasons than found in most of this country. Nevertheless, it is currently under experimentation as a diversification crop, and certainly a good potential domestic market exists in Canada should cultivars and culture be improved sufficiently to suit local climates.

Selected references Bouwkamp 1985; Austin 1987; Purcell et al. 1989; Allan 1991; Opdeam 1991.

Lactuca Lettuce Compositae (Asteraceae) Sunflower family Composées, famille de la marguerite

Genus notes The genus Lactuca contains 50–60 annual, biennial, or perennial herbs that are widely distributed in the Northern Hemisphere and South America, with centres of diversity in the Himalayas and the Middle East (Bailey and Bailey 1976). Several species are native to Canada and several more have been introduced (Scoggan 1978–1979). One species, discussed below, is the garden lettuce of commerce.

Names Scientific (Latin) name: Lactuca sativa L. English common name: lettuce French common name: laitue (f) [Numerous variants designate cultivar classes and groups, for example, celtuce = laitue asperge, butterhead = laitue beurre, head = laitue pommée, romaine = laitue romaine, and leaf = laitue frisée.]

Description and taxonomy

Butterhead (bibb)

Lettuce is a herbaceous annual that has been selected for different forms. These have been divided into several classes (Lipton and Ryder 1989; Nonnecke 1989), as noted below. Crisphead, referred to as var. capitata L. by some authors (Schultze-Motel 1986), is the most commonly grown commercial lettuce in North America. Butterhead, the so-called “bibb” lettuces, have an oily or buttery texture to the inner Crisphead lettuce leaves. Leaf, referred to as var. crispa L. by some authors (Schultze-Motel 1986), includes loose leaf lettuces, the most common type in home gardens. Cos or Romaine, referred to as var. longfolia Lam. by some authors (Schultze-Motel 1986), includes cultivars with upright habit resulting in elongated heads with relatively narrow spatulate leaves.

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Leaf lettuce

Stem, grown for its edible stem, was originally selected in the Orient. It is referred to as var. angustana Irish ex Bremer by some authors (Schultze-Motel 1986) and is known as “celtuce” in Canadian garden catalogs. (The word celtuce is used both to denote a particular cultivar and the stem lettuce category of lettuce.) Latin lettuce has foliage similar to the Cos class, but the leaves are shorter with a loose, open head. The leaves are leathery and tough. This type is not found in Canada and is most noted as a source of resistance to lettuce mosaic virus. Open, loose types of lettuce with distinct coslike leaves were used in ancient Egypt, about 4500 B.C. The ancient Egyptians may have originally cultivated lettuce as a crop for an edible oil that can be extracted from the seeds. Lettuce was popular in the classical Roman and Greek civilizations. It was introduced into China about A.D. 600–900, and stem lettuce evolved there. Lettuce use spread throughout the Mediterranean basin and, by the Middle Ages, Europe was raising cultivars of the classes of lettuce know today. Lettuce was one of the first vegetables to be introduced to the New World by Europeans (Ryder 1986; Nonnecke 1989). Seven wild Lactuca species are taxonomically closely related to cultivated lettuce and one, L. serriola L. (= L. scariola L.), is generally accepted as the wild stock from which cultivated lettuce evolved. Lettuce is fully interfertile with L. serriola (Zohary 1991), and the two readily form hybrids when grown in proximity. Lactuca serriola is native to southern Europe, northern Africa, and central Asia and is found as a weed across Canada.

Uses Most forms of lettuce (crisphead, butterhead, cos or romaine) are used raw in salads or occasionally heated as in tacos. The stem lettuce, “celtuce,” was first selected in China where it is grown commercially. The stem is eaten either fresh or cooked. It is cut off down to the leafy portion of the plant and the outer skin is peeled away to remove the bitter sap. The soft, translucent green core can be eaten fresh, sliced, or diced in a salad. It is also cooked by boiling or frying (Stephens 1978; Lipton and Ryder 1989). Example recipes

Caesar salad (Owen 1978) Celtuce au gratin (Organ 1960) Lettuce leaf Dolmathis (lettuce rolls) (Morash 1982) Lettuce pie (Morash 1982) Lettuce-wrapped and stuffed fillets of fish (Morash 1982) Maltese stem lettuce (celtuce) (Buishand et al. 1986) Salade Niçoise (Owen 1978)

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Importance Lettuce, as the Western World’s most popular salad plant, is in demand at all seasons and thus is one of the principal vegetable truck crops. Europe grows about 2 000 000 t annually (Hinton 1991). Canada often grows over 50 000 t of lettuce yearly, mostly in Quebec. However, this usually represents less than a fifth of lettuce consumption in Canada. Most imported lettuce comes from the United States. The relative popularity of the major types of lettuce are indicated by the following figures. In 1991, in 10 major Canadian markets the following amounts of domestic lettuce were unloaded: 22 390 t of crisphead, 2018 t of butterhead, 4370 t of leaf, 7933 t of romaine, and 1329 t of lettuce grown in greenhouses and hydroponically (Anonymous 1992a). In 1992, in the same markets the following amounts of domestic lettuce were unloaded: 21 388 t of crisphead, 2903 t of butterhead, 5146 t of leaf, 9541 t of romaine, and 2059 t of lettuce grown in greenhouses and hydroponically (Anonymous 1993a).


Lettuce requires substrates high in organic matter, but it will grow on a range of soils including fine sandy loams, loams, clay soils, and muck soils. Soil pH should range between 6.0 and 8.0. Rotation with crops such as tomatoes, cucurbits, corn, spinach, beets, or carrots disrupts the buildup of diseases specific to lettuce in the earth.

Climate

Lettuce is a cool-season, half-hardy crop. The minimum temperature required for germination is 1.7°C, with a range of 4–26°C. In Canada, most commercially grown early crops of field lettuce are transplants. The optimum growing temperature is 15–18°C, with minimum 7°C and maximum 24°C. Above a mean growing temperature of 18°C, lettuce plants tend to bolt (initiate flowering), which reduces leaf production and makes leaves bitter; some cultivars have been selected to resist bolting. Additional water should be provided during dry periods. To produce lettuce seed, flowering can be stimulated by subjecting plants at the 3–5 leaf stage to treatments with gibberellic acid. The growth environment of greenhouse lettuce can be controlled more easily than that of garden plants. Supplemental lighting is necessary during the winter months. New growing techniques include a hydroponic or nutrient film method with a belt system moving seedlings from one end to the other, by which time fully developed lettuce plants have been produced (Nonnecke 1989).


Lettuce is propagated from seed. In Canada, the earliest lettuce crop is usually transplanted. Otherwise, lettuce can be precision-seeded with seeds that have been pelleted, coated, and sized for uniformity. If planted in hot locations, lettuce seeds may be pregerminated and either dry- or fluid-seeded. Various pests and diseases infest lettuce, requiring protective measures. Early shallow cultivation is beneficial to reduce weed competition.

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Harvest and storage

Mechanical harvesting of field-grown crisphead lettuces has been attempted, but handpicking still predominates. Lettuce may be wrapped in perforated plastic, field-packed in cardboard cartons, and vacuum cooled. Delivery of high-quality fresh lettuce depends on rapid removal of field heat and shipping in refrigerated vehicles. For storage for 1 week lettuce is precooled to about 1°C with relative humidity of 90–95%. Greenhouse lettuce, especially that grown Romaine (Cos) hydroponically, is often packed as whole plants, lettuce including the roots. Shredded lettuce is also sold for salads. The lettuce should be cut when dry with a very sharp blade, packaged in plastic bags, and held at 0°C (Lipton and Ryder 1989). Celtuce is grown similarly to lettuce. The early leaves of celtuce (up to about 4 weeks after they first appear) can be eaten, although many find them barely palatable. After the first month the leaves produce a milky, bitter sap. As the plant bolts, the stalk bearing the leaves elongates and can reach heights of more than 1 m. The stem is best harvested when it reaches a diameter of 2.5 cm. The stalks are cut off at ground level and the leaves are stripped off. Alternatively, the entire plant can be pulled and the crown cut off. The outer skin should be removed, ridding the plant of the bitter sap-filled tubes. Harvested stalks keep well under refrigeration (Halpin 1978).

Example cultivars

Crisphead: Gemini, Ithaca M.I., New York, Summertime. Butterhead: Bibb, Buttercrunch, Canada Boston, Oresto, Tom Thumb. Leaf: Grand Rapids, Red Sails, Rouge Crisp, Super Prize. Cos or Romaine: Majestic Red Cos, Parris Island M.I. Cos, Romaine Paris White Cos. Stem: Celtuce. Lettuce breeding was discussed in detail by Ryder (1986). Bettencourt and Konopka (1990) listed institutions in various countries conserving lettuce and celtuce germplasm. Facciola (1990) provided an extensive description of lettuce classes and cultivars available in the United States.


Stylized illustrations of lettuce are often found associated with fertility gods of the early Egyptians on the walls of their tombs, which indicates that the plant was considered to be a sex symbol. This concept likely originated from a supposed similarity to semen of the milky latex streaming from the cut surfaces of stems and leaves of primitive kinds of lettuce. The Roman Emperor Augustus was given the juice of a wild relative of lettuce, L. virosa L., as medicine against a serious illness. Attributing his recovery to the medicine, he built an altar and erected a statue in honor of wild lettuce (Grieve 1978).

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The central stalk of primitive kinds of lettuce appeared phallic to the Romans, who considered such types to be aphrodisiac. By contrast, the Romans termed head lettuce “eunuch’s salad” (Richardson 1990). The milky juice of lettuce, known as Lactucarium, has been considered to be a narcotic from ancient times and has even been used as a substitute for commercial opium (Millspaugh 1974). It is probably impossible to consume enough lettuce to become intoxicated! The genus name Lactuca originates from the Latin lac (or lactlac) for milk, in reference to the milky juice exuding from damaged parts of the plant. Lettuce was the experimental plant used in the 1950s to demonstrate a remarkable physiological process in plants. The seeds of some lettuce cultivars exhibit a kind of dormancy that can be induced or reversed depending on exposure to different kinds of light. Red light converts a substance called phytochrome to a state that activates the germination process, whereas far-red light or darkness converts phytochrome to another state that inhibits germination. In London, England, Brian Richardson’s wife stabbed him to death with a carving knife after he complained about the lettuce leaves on his salad. Since she was a Sunday school teacher, ran a home for the elderly, and never harmed anyone but her husband (who she missed dreadfully) she was jailed only for 2 years (The Ottawa Citizen 1997). Wild lettuce, L. serriola, which is closely related to garden lettuce, has leaves that are vertical rather than horizontal. Under the intense rays of the noonday sun, the leaves receive minimum exposure, but when the sun is near the horizon the leaves receive full insolation–presumably a protective adaptation. The tips of the leaves point north or south, giving rise to the name “compass plant” (a phrase used for several other species that exhibit the same phenomenon). “It’s always best to tear a lettuce rather than cut it, for better absorption of dressing and to prevent discoloration of the cut ends” (Richardson 1990). In ancient Rome during the time of the emperor Augustus (ruling from 27 B.C. to 14 A.D.) it became fashionable to eat salad at the end of a meal. However, when Domitian became emperor (ruling from year 81 to 96), he insisted that the salad course be served at the beginning of the meal (Richardson 1990). Thus began the debate carried down to our time of whether salad should be served at the beginning or end of a meal!

Problems and potential Lettuce is subject to a wide variety of disease pathogens and insects. Strict attention to recommended growing conditions and disease prevention, along with crop rotation, will help reduce damage.

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Lettuce is a primary component of salads in Canada and is in demand throughout the year. Domestic lettuce production represents a small percentage of total lettuce consumption in Canada. Greenhouses provide only about 5% of all domestic lettuce production (Anonymous 1992a). Increased use of greenhouses to produce fresh lettuce during the winter, if economically feasible, would reduce imports. Premium prices can be received for hydroponic lettuce because of the perception that this growing method is more organic. Celtuce is a curiosity confined to home gardens in Canada and has little market potential.

Selected references Halpin 1978; Ryder 1986; Lipton and Ryder 1989; Nonnecke 1989.

Lagenaria Bottle gourd Cucurbitaceae Gourd family Cucurbitacées, famille de la courge

Genus notes The genus Lagenaria has six species of annual herbaceous vines (Bailey and Bailey 1976), native to the Old World tropics and perhaps also the Americas where their status as native or introduced is unclear. The one species that is cultivated is described below.

Names Scientific (Latin) name: Lagenaria siceraria (Molina) Standl. English common name: bottle gourd Also: calabash, suzza melon, zucca (melon), cucuzzi, Italian edible gourd, Tasmania bean, Guinea bean, New Guinea bean, white-flowered gourd, calabash gourd, Chinese preserving melon French common name: courge bouteille (f) Also: calebasse

Description and taxonomy This species is a vigorous, annual, running or climbing vine reaching up to 10 m in tropical areas. The fruit is green initially, turning whitish or yellowish at maturity. Fruits are very variable, with lengths of 10 cm to more than 2 m, weights ranging up to 50 kg, and such shapes as straight, crooknecked, club-form, dumbell-form, twisted, coiled, disklike, and globular. The flesh is white, pulpy, and many-seeded. No taxonomic distinction has been made between cultivated and wild plants, although there is evidence that the two phases differ. The fruits of some wild plants of Lagenaria are rather bitter, in contrast to the fruits of most cultivated forms, which clearly reflects selection for palatability. The bottle gourd may have been independently domesticated in Asia, Africa, and South America, where it is widely cultivated. Bottle gourd is extending its range in subtropical and tropical areas. The following two subspecies are recognized: subsp. siceraria, grown in Africa and the Americas subsp. asiatica (Kobiakova) Heiser, grown in Asia and the Pacific.

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The species probably originated in tropical Africa and was distributed in early times into South America. Bottle gourd may have floated from Africa to South America. Tests have shown that the mature gourds will float for prolonged periods in seawater and that their seeds remain viable (Heiser 1973). Archeological evidence shows use of bottle gourd in Mexico from 7000 B.C. Lagenaria probably reached China during the first century A.D. It may have been one of the earliest crops used in the tropics (Tindall 1983).

Uses The immature fruits of bottle gourd can be cooked and used in vegetable dishes. Bottle gourd fruit is best used like summer squash such as zucchini. It can be sliced, coated with flour, and fried like eggplant, or boiled, diced and creamed. The young leaves or immature shoots may also be hand-picked and cooked. In western Africa the seeds are added to soups (Tindall 1983). Mature bottle gourd fruits are variously shaped and have very hard skin. The hollowed-out gourds have been employed in numerous ways since antiquity. They have been used extensively as containers for holding and carrying water, foods, and other substances. Some gourds make excellent spoons or “dippers” for food and water. Gourds have been turned into musical instruments, pipes, floats for fish nets, birdhouses, masks, and decorative charms (Heiser 1979). Example recipes

Squash (bottle gourd) stew (Morash 1982) Summer squash (bottle gourd) orange cake (Morash 1982)

Importance Bottle gourd is widely grown in tropical areas as a vegetable and for useful gourds. This species is adapted to a hot, dry climate and is much more important in tropical and semitropical regions than in northern North America. In Canada, bottle gourd is not grown commercially and is merely encountered occasionally in home gardens as a curiosity.


Bottle gourd grows well in soil with a high amount of organic matter and pH near 7.0. Good drainage is essential.

Climate

Bottle gourds are tropical plants requiring warm temperatures. Irrigation is needed during dry periods and the plants should receive water at regular intervals throughout growth (Tindall 1983). For gourds grown for ornament rather than for use as a vegetable, at least 140 frost-free days are required to attain maturity from seed outdoors. Lagenaria can be grown for ornament in all provinces of Canada,

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provided that the plants are started indoors. Hot days (29–37°C) and warm nights (not lower than 18°C) result in the best gourds. Propagation and cultivation

In Canada, seeds used to propagate bottle gourd must be sown indoors several weeks early and transplanted outdoors after danger of frost is past. Bottle gourds are grown on poles or trellises in full sunlight. Fruits left on the ground are often misshapen or spotted, whereas unblemished gourds usually require training the vines on the trellis, wall, fence, or arbor provided. To assist in the maturation of fruit, it helps to pinch off immature fruits that begin developing after the first few have started.

Harvest and storage

Bottle gourds are hand-picked as immature fruits for use as a vegetable. In India, about 10–15 fruits per plant are produced, each weighing 0.5–1.5 kg, and average yields are 25 t/ha (Tindall 1983). However, yields comparable to those obtained in hot climates are not possible in Canada. More often than not, fruits of Lagenaria are grown in Canada for use as gourds rather than as a vegetable. Fruits require 100–140 days after germination for development. Immature ornamental gourds decay fairly quickly, and gourds do not attain their best color, or cure and keep properly, unless mature when harvested. Ideally, Lagenaria gourds should be picked when they become light in weight and have turned a light brown, but harvesting may be necessary before these changes occur. Mature gourds are harvested as late as possible before a hard frost. Lagenaria fruit, if mature, can withstand light freezing but not severe frost. To avoid infection, the fruits should be cut, rather than broken off, leaving 5–8 cm of the stem attached, and they should be handled carefully to prevent bruising. After harvesting, the gourds should be washed in warm soapy water and rinsed in a strong solution of a nonbleaching disinfectant such as borax. They are best hung from strings in a well-ventilated room (Hamersma 1974), for 4–6 weeks, or up to 6 months in some cases. Direct sunlight should be avoided during curing. Ripening may be hastened by piercing the ends of the gourds with a darning needle. Any moldy areas may be washed off, or the gourd, if badly molded, should be discarded. Properly cured gourds of Lagenaria should last for years.

Example cultivars

In current Canadian garden catalogs bottle gourd is listed as “Bottle Gourd (Calabase),” and “New Guinea Butter Vine (Cucuzzi).” Bettencourt and Konopka (1990) listed institutions in various countries conserving bottle gourd germplasm.

Additional notes “Gourds” have been defined as members of the Cucurbitaceae with durable, hard-shelled fruit grown for ornament, utensils, or general interest (a few kinds occasionally called gourds have soft flesh and nondurable rinds). The two species most commonly encountered in North America as gourds are L. siceraria and Cucurbita pepo subsp.

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ovifera, the yellow-flowered and white-flowered gourds, respectively. (Other cucurbitaceous genera also furnish gourds, such as Luffa, treated elsewhere in this book.) The fruits of the yellow-flowered gourd are never as palatable as those of the white-flowered gourd. The flowers of the white-flowered gourd open at night, whereas those of the yellow-flowered open about daybreak and usually wilt by noon. The yellow-flowered gourds generally mature 7–10 days earlier than white-flowered gourds grown comparably. White-flowered gourds are often slower to dry than yellow-flowered; they may need 6 months to cure properly, whereas the “pepos” will normally cure in a month or less. Once cured, the gourds may be soaked in hot water for several hours to loosen the outer skin and scrubbed with steel wool or fine sandpaper to remove it. The surface can be waxed with paste or furniture wax, or shellacked or varnished (after rubbing the surface with fine steel wool to create a surface to which the varnish can adhere), or painted. The gourds make attractive home decorations. Lagenaria gourds may be carved into various shapes such as dippers, scoops, storage vessels, and bird houses. Designs can be cut into the surface or burned on with an electric wood burner. Curiosities

In pre-Columbian Peru, the surgical operation of trepanation (removing a piece of the skull) was performed after injuries. A piece of gourd was sometimes used to replace the portion of skull that was removed. The Chinese used to place crickets in small cages to enjoy their singing. About A.D. 1000 they began to hold cricket fights and gourds were used to house the crickets overwinter. Long, slender gourds have been used as phallocrypts (penis sheaths) by primitive societies, mainly in Africa, northern South America, and the southwest Pacific, with the practice best developed in New Guinea (Heiser 1979). Such attire takes a variety of shapes and lengths (some approaching 1 m) and is often worn during battles and ceremonies, and even as everyday clothing. Calabash pipes are made in part from the bottle gourd. The pipes were once supplied entirely from South Africa, where cultivars with straight necks were artificially forced to grow into the desired shape. The pipe is formed by the neck end of the bottle gourd. A bowl of clay, porcelain, or meerschaum is put in the large end of the neck, and a stem is added at the smaller (lip) end. [Note: The word calabash is also used to denote the fruit of a tropical tree, Crescentia cujete L., the calabash tree, whose fruits resemble gourds and are also widely used for utensils.]

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While the blossoms of bottle gourd are pollinated primarily by bees, it appears that nectar-collecting bats may also contribute to its pollination in the native tropical habitat. The flowers have a musklike odor, typical of many nocturnal flowers visited by bats. The narrow end of the bottle gourd reportedly has been used for giving enemas in Ghana and Hawaii.

Problems and potential Bottle gourd is a tropical plant that will remain an occasional oddity of home gardens in Canada.

Selected references Heiser 1979; Tindall 1983.

Lepidium Garden cress Cruciferae (Brassicaceae) Mustard family Crucifères, famille de la moutarde

Genus notes Lepidium contains more than 100 annual or perennial herbaceous plants of worldwide distribution (Bailey and Bailey 1976). One species is notable as a vegetable and is discussed below. Other economically significant species are noted below. L. densiflorum Schrad., common pepper-grass, is a native of Europe. It also occurs in North America where it is uncertain whether it is native or introduced. It was used in Europe as a substitute for watercress (Nasturtium officinale R. Br.) but was not domesticated. Its use as an edible wild plant was discussed by Szczawinski and Turner (1978). L. meyenii Walp., maca, is a minor root crop of the Peruvian Andes, which grows between 3500 and 4000 m and is employed for food and medicinal purposes. The plant is cultivated in central Peru for the enlarged, turniplike root that is used fresh or dried (Yamaguchi 1983; Schultze-Motel 1986).

Names Scientific (Latin) name: Lepidium sativum L. English common name: garden cress Also: peppergrass [Upland cress, as explained below, is better not used for this species.] French common name: cresson alénois (m) Also: cresson de jardin [The latter is ambiguous because it is also applied to Barbarea verna, the true upland cress.]

Description and taxonomy Garden cress is an annual herbaceous plant. The cultivated kind, subsp. sativum, is grown in temperate regions worldwide. Some forms have crisped, curled leaves (subsp. sativum var. crispum [Medik.] DC. of some authors [Schultze-Motel 1986]); these forms are sometimes termed upland cress. “Upland cress” also refers to various species of Barbarea and is advisedly reserved for B. verna (Mill.) Aschers., which is also discussed in this book.

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Garden cress occurs wild in North America and is found along roadsides and in waste places. In Canada, it has been recorded in all provinces with the possible exception of Newfoundland, as well as in the territories (Scoggan 1978–1979). It is uncertain whether the Canadian records all represent the cultivated form that has escaped, or sometimes the genuinely wild form. The wild form, native to Egypt and western Asia including Iran (Schultze-Motel 1986), is subsp. spinescens (DC.) Thell. Garden cress was selected as early as 400 B.C. in Persia and spread to India, Syria, Egypt, and ancient Greece. It was first cultivated as a salad herb in England in 1548 (Szczawinski and Turner 1978). Today it is widely grown in Europe (Simmonds 1976; Halpin 1978).

Uses Garden cress leaves are eaten fresh in salads, soups, and sandwiches, and garden cress sprouts are also consumed. The whole seed pods can be used fresh or dried, as a seasoning with a peppery flavor (Halpin 1978). In Europe, the leaves are processed for use in dried soup packages (Buishand et al. 1986). Example recipes

Peppergrass (garden cress) Tartar sauce (Szczawinski and Turner 1978) Peppergrass (garden cress) omelette (Szczawinski and Turner 1978)

Importance Garden cress is commercially produced in Europe, including Britain, France, the Netherlands, and Scandinavia. It is usually sold for use as sprouts in sandwiches, like alfalfa sprouts (Buishand et al. 1986). No reports seem available for commercial use of garden cress in Canada. It is likely restricted to home usage and may be available in local market gardens or raised as a specialty item for restaurants.


Garden cress grows best on rich soil or well-rotted compost. It is also grown on various substrates in greenhouses and, in the British Isles, is often germinated on moist cotton in homes, to produce edible seedlings (Halpin 1978).

Climate

Garden cress is a cool-season plant. It is adapted to temperatures under 20°C. In hot weather its flavor becomes quite peppery. In

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greenhouses it can be grown under benches away from direct sunlight, to avoid heat (Halpin 1978). The seeds germinate at 18–21°C (Splittstoesser 1990). Propagation and cultivation

Propagation is by seeds, which are sown thickly and are covered either lightly or not at all. Plants are thinned (the removed plants are edible) and watered as needed. Plants are best grown in reduced sunlight. Successive plantings are recommended for a series of harvests outdoors throughout the growing season. Garden cress is well adapted to greenhouse or indoor culture. Seedlings can be grown in flats, trays, or pots. If sprouts are desired, the plants are sown thickly in flats or jars (Halpin 1978).

Harvest and storage

Garden cress leaves are best picked before the plants flower. The entire plant can be used, or most leaves can be removed, allowing regrowth for a second harvest (Halpin 1978). Garden cress sprouts are harvested when the first true leaves turn green, usually 10 days after sowing (Splittstoesser 1990). In Europe, the seedlings are sold growing in small boxes. These keep for about 2 weeks at 0–1°C with high humidity (Buishand et al. 1986).

Example cultivars

Extra Curled, Fine Curled. Lepidium sativum is sometimes sold as “curled cress,” “garden cress,” “pepper cress,” and “pepper grass” in Canadian garden catalogs. Bettencourt and Konopka (1990) listed institutions in various countries conserving garden cress germplasm.


Garden cress was scheduled for a space mission in 1997 (Shuttle Mir Mission -05, in the Spacehab module onboard Atlantis), to study its growth in response to limited gravity.

Problems and potential Garden cress is a very minor crop in Canada, used in a few home gardens. It has potential for commercial marketing as a salad plant and, by growing the plant indoors, as sprouts year-round.

Selected references Halpin 1978; Buishand et al. 1986; Small 1997.

Luffa Loofah Cucurbitaceae Gourd family Cucurbitacées, famille de la courge

Genus notes Luffa contains seven species; four are distinctive natives of the Old World, and three are rather similar species of the Neotropics. Two of the Old World species include domesticated plants: L. acutangula, angled loofah, and L. aegyptiaca, smooth loofah (Schilling and Heiser 1981; Heiser and Schilling 1988, 1990), both discussed below. It is unclear which of the two species is advertised in seed catalogs in Canada, perhaps only smooth loofah.

Angled loofah

Name Scientific (Latin) name: Luffa acutangula (L.) Roxb. English common name: angled loofah Also: Chinese okra, angled luffa, sing-kwa French common name: luffa (m) Also: papengaye, gombo chinois

Description and taxonomy Angled loofah is an annual herbaceous vine. The cultivated form of angled loofah, var. acutangula, has larger fruits than the wild types. It probably originated in India. Cultivars were selected locally where it has been grown commonly in southeast Asia. It is known as “cee-kwa” or “cee gwa” in China. In parts of the tropics individual plants produce 15–20 fruits. Fruits of angled loofah have a spongy interior, similar to smooth loofah (discussed below) but are smaller in size. Two wild forms are found: var. amara (Roxb.) C.B. Clarke, an indigenous or feral form with small and very bitter fruits, confined to India var. forskalii (Harms) Heiser & Schilling, in Yemen.

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The latter may have developed from escapes of the cultivated variety (Heiser and Schilling 1988, 1990).

Uses Angled loofah fruits are harvested when immature and cooked in vegetable dishes, stews, and soups. Normally the ridges are cut off the angled fruits with a vegetable peeler to prepare them for eating; the skin can be left on. Young leaves, blossoms, and immature seeds are also edible. They can be simmered until tender and added to vegetable dishes (Harrington 1978). While pumpkin seeds are edible, not all members of the Cucurbitaceae family produce edible seeds. Luffa acutangula seeds should not be eaten, nor should they be allowed to be eaten by domestic animals (the same applies to other species of Luffa). The seeds have been used as a drastic purgative, 15 to 20 seeds provoking vomiting and diarrhea (Watt and Breyer-Brandwijk 1962). Mature fruits can be peeled and the fibrous interior used as a sponge or scrub brush (Halpin 1978; Yamaguchi 1983). Luffa sponges are widely sold in the cosmetic and bath sections of stores and are popular because of their gentle exfoliating effect on the skin. They are natural and biodegradable and therefore attractive to the environmentally conscious consumer. In some countries luffa is used to make scrubbing products for pots, pans, barbecue grills, tires, and other surfaces that will withstand abrasion. The sponges have also been transformed into industrial products such as filters, insulation, and packing materials. Luffa sponges are sometimes also made into dolls, hats, toys, and other decorative items. Example recipes

Baked stuffed loofah (Harrington 1978) Chinese okra with shrimp (Richardson 1990) Chinese stir-fried loofah (Harrington 1978)

Importance Angled loofah is cultivated in India, tropical Asia, and parts of the Caribbean (Tindall 1983). It is grown less than smooth loofah. Its status is uncertain in Canada, but it can be raised as a garden curiosity here. Loofah sponges are occasionally sold in health food stores.


Angled loofah grows best on soils high in organic matter, but fair yields can be obtained on sandy loam soil.

Climate

Angled loofah should be started indoors in Canada and transplanted outdoors after danger of frost. Plants grow well at temperatures above

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25°C. Although growth may suffer with excessive rainfall, irrigation is necessary during dry periods (Harrington 1978; Tindall 1983). Propagation and cultivation

Propagation is by seeds started indoors. These may require 2 weeks to germinate and the soil must be kept moist. To speed growth in temperate climates, luffa gourds are best grown on raised beds with black polyethylene mulch to catch and retain the sun’s heat. The plants should be provided with a trellis or fence at least 2 m tall. Removing the first flowers at the bud stage increases fruit production. The harvested buds can be cooked and eaten (Harrington 1978).

Harvest and storage

There are two harvest periods; early for immature vegetables, late for mature “sponge.” Immature fruits are harvested when still green and 10–15 cm long. They should be consumed when young. The mature fruits are bitter and inedible but can be harvested for the spongelike interior (Harrington 1978).

Example cultivars

The cultivar Cee Gwa is sold in Canadian garden catalogs, sometimes as “Chinese okra.” However, the description of the fruit is almost certainly that of smooth loofah. It is therefore uncertain if angled loofah is actually available from any Canadian source. It is available in the United States.


Although some British colonists in India found the taste inferior to that of familiar vegetables such as green peas, Indians considered angled loofah to be one of the best of indigenous vegetables and used it extensively in curries (Hedrick 1972). Gourds were so important to Haitians that in the early 1800s they were made the national currency. To this day the standard Haitian coin is called a “gourde.”

Problems and potential Angled loofah can be grown in Canada as a curiosity of home gardens. This tropical vegetable has no commercial potential in Canada.

Selected references Halpin 1978; Harrington 1978; Tindall 1983; Heiser and Schilling 1990.

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Smooth loofah

Names Scientific (Latin) name: Luffa aegyptiaca Mill. English common name: smooth loofah Also: sponge gourd, dishcloth gourd, smooth luffa, sze-kwa, common vegetable sponge French common name: luffa (m) Also: courge-torchon, pétole

Description and taxonomy Smooth loofah is an annual herbaceous vine. The correct botanical name to be used for this species is controversial. Luffa cylindrica (L.) M.J. Roem. is in wide usage. However L. aegyptiaca is arguably correct (Heiser and Schilling 1990). Smooth loofah is a vigorous, climbing, annual plant. The domesticated forms have been placed in var. aegyptiaca and differ from wild forms in having more deeply furrowed, less-bitter, larger fruits. The site of domestication is unknown. Heiser and Schilling (1990) argued that it is unlikely India, as has been suggested, because the wild form occurs farther east in Asia, Malaysia, and the Pacific. The domesticated smooth loofah was known in China in A.D. 600 and is now found in many tropical regions (Tindall 1983). The wild form, var. leiocarpa (Naud.) Heiser & Schilling, ranges from Burma and the Philippines to northeastern Australia and Tahiti.

Uses Smooth loofah is used like angled loofah. It is cultivated for food in India, where it is called “ghia”. The immature fruits, leaves, flower buds, and immature seeds can be cooked and eaten in vegetable dishes (see information for previous species regarding toxicity of seeds). The Burmese consider it to be a delicious vegetable. The unripe fruit has been used to make pickles by the Arabians (Grieve 1978). To obtain sponges, the mature fruits are dried and peeled, leaving the inner fibrous core (Harrington 1978; Tindall 1983). Example recipes

Loofah shrimp stir-fry (Harrington 1978) Roasted loofah seeds (Harrington 1978)

Importance Smooth loofah is used as a vegetable and for its spongy interior in many parts of the world. Yields of up to 60 000 fruits per hectare and

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50 t/ha have been recorded in Japan (Tindall 1983). In Canada, smooth loofah is grown as a curiosity in home gardens. In the southeastern United States, particularly in North Carolina and Florida, attempts are underway to produce large acreages of luffa gourds for sponge production.


Smooth loofah does best in light soils that have high organic matter content. Soil pH of 5.5–6.5 is suitable. Excess fertilizer reduces fruit production.

Climate

Smooth loofah, a plant adapted to the tropics, should be started indoors in Canada. The seeds have a thick seed coat and may take 2–3 weeks to sprout. The seedlings can be transplanted outdoors after danger of frost. Smooth loofah performs well at temperatures above 25°C. Irrigation is required during dry periods (Harrington 1978; Tindall 1983).


Propagation is by seeds planted indoors and transplanted after all danger of frost. The seeds germinate slowly, and often sporadically, and need constant moisture. The plants are grown on trellises or fences at least 2 m tall. Moist soil is important (Harrington 1978).

Harvest and storage

Immature fruits, which are eaten as a vegetable, are ready for hand-harvesting when they are 15–20 cm long. Mature fruits are left on the vine until the stem yellows and the skin begins to dry and fade. These are collected, peeled, and used as sponges (Halpin 1978). In many parts of Canada the growing season is too short to produce quality mature fruit. Much of the luffa seed sold for home garden production has been found to be unsuitable for producing high-quality sponges. Although it is unlikely that many Canadians will be able to produce either gourds for ornament or sponges, because of the short growing season, the following suggestions may be noted. At maturity, dried gourds will be brown, light, and rattle with loose seeds when shaken. After the first killing frost, gourds are best dried in a warm, well-ventilated area. If dried on the vine in wet weather, discoloration may result. To obtain the sponges, mature gourds may be soaked in warm water from 5–20 min, until the sponges slip out of their skins. Remove the excess pulp and rinse the freed sponges in a 10% chlorine bleach solution to lighten them.

Example cultivars

One Canadian garden catalog offers seeds of Cee Gwa, listed as Chinese okra. This name normally applies to L. acutangula, but the description of the fruits of Cee Gwa is “… rounder cucumber shaped, not the more angular okra-shaped type.” This description almost certainly refers to smooth loofah. Other Canadian catalogs simply offer “loofah.”

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The interior, netted fibres, under the name “loof,” are used in Turkish baths as sponges (Hedrick 1972). Luffa aegyptiaca gourds are often seen hanging from telephone poles in Honduras.

Problems and potential Smooth loofah is likely to remain a novelty in Canadian home gardens. The production of the spongy mature fruits is uncertain because of the short growing season in most parts of Canada.

Selected references Tindall 1983; Heiser and Schilling 1990; DeCourley 1993; Davis 1994.

Lycopersicon Tomato Solanaceae Potato family Solanacées, famille de la pomme de terre

Genus notes Lycopersicon is composed of nine species of annuals or tender perennials that are native to the New World tropics (Warnock 1988). One species, L. esculentum, tomato, is used worldwide and is one of the most important vegetables. Another species, L. pimpinellifolium, currant tomato, is occasionally employed as a ground cover and has edible fruits. Both are discussed below.

Common tomato

Names Scientific (Latin) name: Lycopersicon esculentum Mill. English common name: tomato French common name: tomate (f) (Variants designate various kinds, for example, tomate cerise = cherry tomato, tomate oblongue = plum or Italian tomato.)

Description and taxonomy Tomato is a tender tropical perennial herb that is grown as an annual in temperate parts of the world. There are two recognized varieties: var. esculentum, the cultivated tomato var. cerasiforme (Dun.) Gray, cherry tomato. The latter includes wild forms found in Bolivia, Peru, and Columbia in South America, most Central American states, and parts of Mexico (Taylor 1986; Warnock 1988). Variety cerasiforme is widely regarded as the progenitor of the domesticated var. esculentum. Mexico is often thought to be the major area of domestication, at least of the familiar large-fruited varieties of commerce. Rick and Holle (1990) noted that there may have been more than one centre of origin and suggested a secondary place of origin in the Large red eastern Andes. garden tomato

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The tomato was already used by the Aztecs when Europeans first arrived in the Americas. The Spanish are generally thought to have introduced tomatoes to Europe in post-Columbean times (although some literature is suggestive of the presence of tomatoes in the Old World prior to 1492). Because the tomato is a member of the nightshade family (Solanaceae), it was considered poisonous in many countries. Gradually its fruits were accepted as a vegetable. They were reintroduced to North America, and by the 1860s attempts were made to improve the tomato and develop new cultivars (Nonnecke 1989). Many field-grown tomatoes in Canada are determinate. Such plants are bushlike in growth, with a terminal inflorescence that produces a limited number of fruits. Indeterminate plants are more vinelike, lack a terminal inflorescence, require staking, and continue to produce tomatoes for a prolonged period.

Uses Ripe tomato fruits can be used raw in salads or cooked as an ingredient of stews, soups, and of meat, fish, and pasta dishes. Tomatoes are a major component of sauces and condiments used in cooking in many parts of the world, exemplified by Italian pastas and Mexican salsa. The fruits can be turned into excellent juice. Mature green tomatoes can be fried or added to stir-fries, stews, and even mince meat for pies and tarts. Tomatoes are processed into many kinds of pastes, sauces, relishes, and other condiments (Nonnecke 1989). Among the memorable convenience foods of the tomato are pizza and tomato catsup. Example recipes

Baked tomatoes with Provençal-style crumb topping (Morash 1982) Cherry tomatoes with smoked fish pâté (Morash 1982) Chicken breasts with tomato à la Marengo (Morash 1982) Hot tomatoes stuffed with rice (Morash 1982) Mushrooms stuffed with fresh tomato purée (Levy 1987) Ossobuco (with veal) (Morash 1982) Piccalilli (green tomato pickles) (Morash 1982) Plum tomato with shallot purée (Levy 1987) Portuguese plum tomato sauce (Richardson 1990) Sun-dried tomato pasta sauce (Richardson 1990) Tomato, avocado, and shallot salad (Richardson 1990) Tomato pie (Organ 1960)

Importance The tomato is likely Canada’s most popular home-garden vegetable. Endearing features include excellent taste, attractive appearance and color, and dietary versatility. The tomato is the second most-consumed vegetable worldwide per capita, next to the potato.

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About 2 000 000 ha are planted annually worldwide, with the United States leading in volume and yield per hectare (Nonnecke 1989). In the 15 years before 1986, world tomato production increased on average 1.3 million tonnes per year (Allen Stevens 1986). The Canadian domestic supply represents about 60% of all tomatoes used in this country and more than 10% of the value of fresh vegetables used in Canada (Coleman et al. 1991). Greenhouse tomatoes are very important in some countries, particularly in colder climates. In northwestern Europe, 5000 ha of greenhouses produce 800 000 t of tomatoes (van de Vooren et al. 1986), and in Canada Yellow plum tomato about 200 ha of greenhouse tomatoes, often over 30 000 t, are grown annually, with the biggest concentration (70 ha) located around Leamington, in southwestern Ontario (Jarvis and McKeen 1991).


Field tomatoes should not be grown on soil recently planted with either tomatoes or potatoes, because soil pathogens are likely to accumulate. Light, warm, sandy soils are preferred by growers, especially for early crops. Heavier soils are best for maximum production and will sustain the crop through extremes of drought and heat. Organic matter worked into the soil is beneficial (Chong 1976). Soil pH can range from 5.5 to 7.5. Greenhouse tomatoes are traditionally grown on soil beds. Light-textured soils are preferred because earliness to market is desirable. Some growers use soilless media such as sawdust or nutrient film techniques, with water containing balanced nutrients flowing over the tomato roots in a small plastic-lined tunnel (Maas and Adamson 1980; Nonnecke 1989). The effects of plant spacing in greenhouses were studied by Papadopoulos and Ormrod (1990, 1991).

Climate

The ecological requirements of tomatoes reflect their desertlike, Andean origin. They need moderately high day temperatures (21–28°C) and moderately cool nights (15–20°C) for optimum growth and development. The tomato is daylength neutral in respect to flowering, but, during relatively long days, growth and dry matter content of the fruits may be better than during shorter days. The tomato plant is intolerant of waterlogged soil or high humidity (over 80%), both of which promote diseases. Good water availability is essential during fruit development. Field-grown tomatoes destined for shipping or processing are generally transplanted because of the threat of frost in all parts of Canada, although some direct seeding of processing tomatoes occurs.


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Most of the transplants (98%) are grown in south Georgia and shipped bare-rooted to growers. However, recent studies in Ontario have shown that tomatoes grown domestically in multicelled plastic trays in greenhouses can be superior in production and quality (Liptay 1987a, 1987b). Nutrient root dips of 30–60 min improved survival of transplants from Georgia (Muehmer and Brimner 1987). Tomatoes transplanted into home gardens perform well if hardened (gradually acclimated) by reducing temperature to about 15.5°C, withholding fertilizer, or keeping the plants on the dry side. Gradual exposure to outdoor conditions is a good practice (Chong 1976). Germination occurs when soil temperatures are between 15.5 and 29°C, with an optimum of 29°C. The most temperature-sensitive period is during flowering, because flowers do not normally develop when temperatures are below 15°C or above 35°C. The optimum range for flower development is 21–24°C. Temperature requirements are more easily controlled for greenhouse than for field tomatoes. However, supplementary lighting is necessary during Canadian winters because the plants require high light intensity for production (Nonnecke 1989). Supplementary watering is needed during periods of drought. Care must be taken to maintain water availability. Water imbalance and related calcium:iron imbalance can result in blossom-end rot. Propagation and cultivation

Propagation is by seeds usually sown indoors in Canada. For field-grown tomatoes the seedlings are transplanted after all danger of frost is past. Field-grown tomatoes destined for fresh market were traditionally tied to stakes or trellises. However, the advent of determinate and semideterminate cultivars has meant that fewer shipping tomatoes require staking. Shipping tomatoes are rarely ripe, except for local markets. They are harvested at various stages of maturity, from mature green to fruits with varying degrees of color. Processing tomatoes are occasionally direct-seeded in Ontario, but most are transplanted. The transplants are spaced to accommodate mechanical harvesters. Transplanters capable of planting high densities of plants may be employed. However, many growers still hand-pick tomatoes and spacing is arranged to accommodate the pickers (Nonnecke 1989). Greenhouse tomato production is a specialized operation. The major concern is the buildup of soil diseases and pathogens that can result in remarkable loss of plants. The substrate is generally sterilized (usually by steam). Plants are started in individual containers and, at the desired stage, they are transplanted into the substrate. Regular analysis of soil and plant tissue is conducted to monitor nutrient conditions. The growing plants are attached vertically to twine or wire that is joined to overhead wires connected to beams. Plants are usually trimmed to one stem and the lower, less efficient leaves are often removed. Pollination of the first and second flower clusters takes place every second day between noon and 2 P.M. It is achieved by hand with a feather duster or mechanically by shaking the stem so that pollen spills out of the anthers onto the female reproductive organs. Succeeding clusters may be pollinated either in the same manner or by tapping the overhead wires (Maas and Adamson 1980).

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Harvest and storage

The tomato market (including greenhouse and field-grown fresh tomatoes, processing tomatoes destined for juice, whole pack tomatoes that are canned whole, and paste) requires careful quality control. Processors want mature but not fully vine-ripened fruits that are too soft to handle in bulk. By contrast, the supermarket buyer wishes ripe-looking tomatoes. Tomato color is used as the major criterion for time of harvest. Other factors, such as internal solids, acidity, and shape (round to pear-shaped, elliptical to flattened) are also considered (Nonnecke 1989). Harvesting of fresh tomatoes has traditionally been labor-intensive, revolving about the sequential development of ripe fruit, especially in greenhouse production. Mechanical harvesting has been attempted but is still limited. Harvested fruits are cooled to reduce respiration (Geisenberg and Stewart 1986). However, the more immature the fruits the more sensitive they are to chilling damage. Mature green fruits are sensitive to temperatures below 10°C, while red fruits can be held at 2–5°C for several days. Chilling injury elicits metabolic disorders, notably disease susceptibility (Frenkel and Jen 1989). Green fruits continue to ripen after picking. Relative humidity should be held at 85–95%. Ripening can be controlled by exposure to ethylene for 12–18 h at 20°C, thereby reducing by half the normal ripening time. Fully ripe tomatoes have a shelf life of 2–5 days at temperatures of 0–5°C. Processing tomatoes are increasingly mechanically harvested in Canada. A single destructive harvest is particularly economical in view of labor charges for hand-harvesting (Geisenberg and Stewart 1986). Modern harvesters allow for sampling and grading of tomatoes directly in the field and the removal of many contaminants (such as rocks, dirt, and extraneous plant material). Ethephon is often applied to promote uniform ripening of fruits.

Example cultivars

Greenhouse tomatoes: hybrid red (spring and fall): Caruso, Cobra, Jumbo, Simba hybrid red (fall only): Boa, Buffalo, Furon hybrid pink: Hybrid Pink CR0864, Hybrid Pink KR-15. Field tomatoes: hybrid staking (indeterminate): Better Boy VFN, Burpee’s Early Pick, First Lady VFNT, Ultra Magnum VFT hybrid bush (determinate): Celebrity VFNT, Daybreak VFT, Mountain Pride VF hybrid cherry tomatoes: Pink Droplet VFNT, Sweet Million, Sweet 100 hybrid paste: Capri VF, Milano bush tomatoes: Arctic Maxi, Bonney Best, Bonneyvee, Manitoba, Rocket, Starfire paste tomatoes: Bellestar, Roma VF, San Marzano low acid: Caro Rich, Jubilee, White Beauty novelty colors: Gold Nugget, Lemon Boy, Yellow Stuffer


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Malo and Bourque (1992) described trials of both determinate and indeterminate tomato cultivars in Montreal. Facciola (1990) provided an extensive description of classes and cultivars available in the United States. Tomato breeding was discussed extensively by Tigchelaar (1986). Wild sources have proven vastly richer than cultivated tomatoes in genetic variation for genetic Pear-shaped or improvement (Allen Stevens and Rick 1986). Collections fig tomato of tomato germplasm are stored in many parts of the world including Plant Gene Resources of Canada, Agriculture and Agri-Food Canada, Saskatoon, Saskatchewan (Loiselle 1984; Bettencourt and Konopka 1990).

Additional notes The foliage and immature green fruits of tomatoes contain the toxic alkaloid tomatine, and poisoning of livestock has been reported. However, the tomatine content in mature green or colored fruits is minimal or nonexistent. Curiosities

Tomatoes were first described in Europe in 1554, in Italy, where they were called “pomi d’oro” (gold apples) indicating that some early introductions were yellow-fruited. Later, as tomatoes became more widely appreciated, it was known as the “love apple” from the early French name “pomme d’amour.” Sir Walter Raleigh’s gift of a tomato plant to Elizabeth I started a fad in England of growing the species as an ornamental curiosity (Richardson 1990). Early introductions in colonial America were not always successful. An Italian painter brought tomato seeds to Salem, Mass., in 1802 but found it difficult to interest anyone in even tasting the fruits (Hedrick 1972). Thomas Jefferson (1743–1826), third president of the United States, was the first American to grow tomatoes, in 1781. He tried to interest his countrymen in eating tomatoes, but as in other areas where this vegetable was unfamiliar, it was avoided (Richardson 1990). In a dramatic demonstration that tomatoes were not poisonous, as was widely thought, Colonel Robert G. Johnson ate a basketful on the courthouse steps in Salem, New Jersey, at noon on September 26, 1820. The genus name of the tomato, Lycopersicon, comes from the Greek lykos, wolf, and persikon, peach–figuratively, “like a wolf in sheep’s (peach’s) clothing,” which reflects the belief that the tomato appears tasty but is poisonous. In addition to Lycopersicon, the word tomato is associated with two other genera that produce edible fruits. Husk tomatoes or

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strawberry tomatoes are the fruit of species of Physalis. The tropical tree tomato is Cyphomandra betacea (Cav.) Sendtn. A wild form of Lycopersicon esculentum, L. esculentum var. minor Rick (L. cheesmanii Riley var. minor [Hook.] Mill.), grows on the coasts of the Galápagos Islands, where the fruits are eaten by the Galápagos tortoises. The seeds germinate well only if they pass through the digestive tracts of the tortoises, which takes from 1 to 3 weeks. Tomato plants may easily be grafted to potato plants, and such graft hybrids are termed pomatoes or topatoes. This clever combination can produce edible underground storage organs and edible fruits simultaneously. Tomatoes were once grafted experimentally to rootstocks of jimson weed (Datura stramonium L.) in an attempt to combat root-infecting nematode worms. However, toxic alkaloids generated by the root system of the jimson weed turned up in the fruits, producing toxic tomatoes! A full-grown tomato plant produces as many as 25 000 seeds. So-called “black tomatoes” (usually various shades of brown or purple) are offered as garden curiosities (for sources see Organic Gardening, Nov. 1992, 39(8), p. 7). In 1962 a wild Peruvian tomato was collected, whose genes have been estimated to have a value for the improvement of tomatoes of more than 20 million American dollars annually (Small and Cayouette 1992; H. Iltis, personal communication). The first genetically engineered crop was developed in 1982 at Washington University in St. Louis, Missouri. The first genetically engineered crop plant approved for commercial marketing (in 1994) was the Flavr-Savr tomato—designed to slow fruit ripening and increase shop life (Levetin and McMahon 1996). This has not been much of a market success, possibly because aside from its keeping qualities, other available tomatoes are more desirable.

Problems and potential Commercial tomato production will remain an important part of the Canadian fresh and processed vegetable industry. New cultivars are constantly being bred for several traits. Resistance to disease pathogens (fungi, bacteria, viruses), as well as insects and nematodes, is very important. The large number of diseases that can affect tomato production in Canada are discussed by Jarvis and McKeen (1991). Other traits of interest include male sterility, fruit quality (solids, acidity, color, nutrients, flavor, firmness), adaptability to mechanical harvesting, and suitability for greenhouse production (Allen Stevens 1986). For example, research is being conducted to produce tomatoes with less water (normally 95%) and more solids that will enhance paste and juice production (Wood 1992). In the future, consumers may be able to buy tomatoes, at all times of the year from their supermarket, that are indistinguishable from


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vine-ripened tomatoes from the backyard. Through genetic engineering, new cultivars such as Flavr Savrs can be left to ripen on the vine and yet still be firm enough to ship. Tomatoes from this cultivar remain fresh for 2 weeks after harvesting, nearly twice as long as conventional tomatoes. The genetic engineering was achieved by antisense RNA technology that suppresses the production of a softening enzyme, polygalacturonase, which attacks pectin in the cell walls of ripening fruits, rendering them soft. Other work has centered on various strategies for manipulating the biochemical pathways for ethylene synthesis, a chemical that hastens the ripening process (Brunt 1992).

Selected references Chong 1976; Maas and Adamson 1980; Atherton and Rudich 1986; Nevins and Jones 1987; Rick and Holle 1990; Jarvis and McKeen 1991.

Currant tomato

Names Scientific (Latin) name: Lycopersicon pimpinellifolium (Jusl.) Mill. English common name: currant tomato French common name: tomate groseille (f) (Vilmorin-Andrieux 1885)

Description and taxonomy Currant tomato is a perennial herbaceous vine that has not been domesticated. It typically grows at low elevations in Peru along the coast and river valleys (generally below 1000 m). All native populations encountered are inbreeders, although some individuals show varying degrees of outbreeding. Currant tomato’s small colored fruits (ca. 1 cm in diameter) resemble those of the familiar tomato, L. esculentum. These species can be hybridized, and currant Red currant tomato tomato is the only wild species of Lycopersicon to show natural introgression (i.e., the transfer of genes of one plant species into another following hybridization) with tomato. Currant tomato intergrades with L. esculentum var. cerasiforme in

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some parts of its range. Either currant tomato is the direct ancestor of tomato or both could have evolved in parallel from a green-fruited ancestor (Taylor 1986).

Uses Currant tomato fruits can be used raw or cooked, as with the familiar conventional tomato. Because of their small size the berries have been found to make excellent pickles (Hedrick 1972). The plant is also useful as a ground cover on poor soils (Taylor 1986). It can also be used as an ornamental. Example recipes

Tomato and egg canapés (Levy 1987)

Importance Currant tomato is of limited importance as a cultivated vegetable and is grown mainly as a ground cover, although the small fruits are edible. It is a curiosity of home gardens in Canada and seems not to be raised commercially. It has been useful in breeding resistance into tomato for Fusarium wilts and bacterial speck (Allen Stevens and Rick 1986; Taylor 1986).


Currant tomato can be grown on soils suitable for the conventional garden tomato. However, it also can grow on poor soils when used as a ground cover for waste areas, brush piles or rubbish heaps.

Climate

Currant tomato is similar to the cultivated tomato in its climatic requirements. It is susceptible to cool temperatures, growth stopping below 15°C.


Currant tomato is propagated by seeds. Little care is required, but support such as a trellis can be provided if desired.

Harvest and storage

The fruits are hand-picked when a red color develops throughout (Warnock 1988).

Example cultivars

One Canadian seed catalog provides currant tomato as “Tomato, wild.” Bettencourt and Konopka (1990) listed institutions in various countries conserving currant tomato germplasm.

Additional notes The currant tomato was first illustrated in 1725 but not as a cultivated plant. It was first mentioned in American literature in 1863 as the “grape” or “cluster” tomato.


Curiosity

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The common name for this vegetable comes from the fruits that are barely larger than currants (fruits of species of Ribes).

Problems and potential Currant tomato has no market potential and will remain a garden novelty in Canada. Its use as a ground cover of waste places could increase, as this constitutes a form of low-input “organic” agriculture. It will likely continue to be a valuable source of germplasm for plant breeders of cultivated tomato.

Selected reference Warnock 1988.

Matteuccia Ostrich fern Aspidiaceae Ostrich fern family Aspidiacées, famille de la dryoptère In much of the older literature Matteuccia is placed in the Polypodiaceae, whereas the modern consensus is that it belongs to the Aspidiaceae.

Genus notes The genus Matteuccia has three species of herbaceous perennials, found in various parts of Eurasia and North America (Bailey and Bailey 1976; von Aderkas 1984). One species is edible and is discussed below.

Names Scientific (Latin) name: Matteuccia struthiopteris (L.) Todaro English common name: ostrich fern Also: fiddlehead, shuttlecock fern French common names: tête de violon (f), crosse de fougère (f) Also: fougère de l’autruche [(Boivin 1992) recommends avoiding tête de violon while Fleurbec (1994) recomends that this phrase designate only the edible young uncurled leaves, and that the plant should be called la matteucie fougère-à-l’autruche.]

Description and taxonomy Ostrich fern is an elegant fern sometimes growing to a height of more than 2 m and with leaves sometimes longer than 2 m. It is native to many parts of the northern hemisphere. Cultivars have not yet been selected. This fern is gathered from wild stands for consumption, although some experimental cultivation of clones is discussed below. In Canada, ostrich fern grows in low open ground, alluvial thickets, and rich woods in parts of all provinces and territories (Cody and Britton 1989). The species is common in eastern Canada but rare west of Manitoba and in the Yukon. Some authors suggest that no varieties of ostrich fern merit recognition (Scoggan 1978–1979; von Aderkas 1984). However, several varieties have been recognized, based on color and hairiness of scales on the rhizome and on the form of the base of the leaves. These include the following:

Matteuccia (ostrich fern)

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var. struthiopteris, the most widespread form of Eurasia, with a conspicuous blackish central band on scales of the rhizome and stripe bases var. pensylvanica (Willd.) Morton, of North America, with uniformly pale brown scales var. pubescens (Terry) Clute, from Matane Co., Gaspé Peninsula in Quebec, with small hairs on the central leaf stalk (instead of normally hairless). The edible plant part is the short (up to 15 cm), curled-up young leaf that first emerges and uncurls in the spring (May and June). As with other ferns, these are called “crosiers” (for their similarity to a bishop’s staff), or more familiarly “fiddleheads,” and the latter name is generally used to refer to the crop. Mature fern leaves are usually called fronds. Once the young fronds have emerged from the ground, they must be picked within a few days. Otherwise the tips uncurl and the leaves become inedible. At the correct stage the fiddleheads are tightly curled, with green coils covered in brown papery scales. They should be 2–4 cm in diameter, with a short piece of stem extending beyond the coil. Native Americans were using the ostrich fern when European colonists arrived. The entire crown was dug up and roasted before eating. The Malecite Indians of the Saint John River valley in New Brunswick have traditionally harvested fiddleheads as a spring tonic and have sold them at local markets (von Aderkas 1984).

Uses Fiddleheads are sometimes eaten raw (see warning, below) but generally they are served cooked. The preferred method is to steam them until tender and flavor them with seasonings and lemon or sour cream. Fiddleheads can be frozen after slight blanching (Szczawinski and Turner 1980). They are also preserved by pickling and canning. In Europe, Norwegians have used ostrich fern as fodder for goats and have made a fern beer. In Russia it has been served as a remedy for intestinal parasites (von Aderkas 1984). Ostrich fern is also used as an ornamental plant in gardens. It provides an attractive plant at the back of flower beds and serves as a excellent foundation planting beside houses. It is important to note that ostrich fern spreads aggressively and may prove difficult to confine. Example recipes

Baked fiddleheads (Turner and Szczawinski 1978) Fiddlehead ferns with nutmeg cream (Schneider 1986) Fiddleheads in mushroom sauce (Richardson 1990) Fiddleheads with brook trout meunière (Owen 1978)

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Fiddleheads with white wine (Turner and Szczawinski 1978) Marinated fiddleheads (Schofield 1989) Steamed fiddleheads (Turner and Szczawinski 1978)

Importance Other ferns are eaten, but the ostrich fern is the most economically important edible fern in the world. It is generally considered a gourmet item. Its major area of use is the Maritime Provinces of Canada and neighboring Maine. About 200 t/year are harvested in New Brunswick, about four times more than in Maine. Fiddleheads are also harvested in Quebec and Vermont, and interest is developing in other areas. One Maritime food processor provides frozen fiddleheads to supermarkets and produces 50–100 t annually (von Aderkas 1984). Fresh fiddleheads are available seasonally, in May and June in Canada. In 1991, about 50 t of domestic and 4 t of imported ostrich fern were unloaded at 10 major market centres in Canada (Anonymous 1992a); in 1992, 43 t of domestic fiddleheads were unloaded in these markets (Anonymous 1993a).


In its native habitat ostrich fern grows in low open ground, alluvial thickets, and rich woodlands (Cody and Britton 1989). Fiddleheads planted as ornamentals have proven to tolerate a variety of soils. In the Maritime Provinces, soil pH averages 5.8 (von Aderkas 1984).

Climate

Ostrich fern is a native plant capable of growing across Canada. No special climatic requirements need be met if grown around the home or garden as a crop. Although ostrich fern generally grows in half or full shade, in field trials it has been successfully grown in full sunlight. Moist soil is always desirable, but especially if ostrich fern is grown in full sun.


The ostrich fern produces horizontal underground rhizomes with new crowns developing along their length. Crowns of fiddlehead, surrounded by papery scales, overwinter in a dormant state. This dormant crown may have as many as 40 leaves (i.e., fiddleheads) at different stages, from primordial to fully developed, ready to emerge the following spring (von Aderkas 1984). Plants can be propagated by transferring the newer crowns to desired locations. Deep planting and mulching improved vigor and production in New Brunswick (Estabrooks 1989); this method increased both the number of leaves per crown and the leaf height, although new crown development was not enhanced. Dormant sprays with certain herbicides have provided


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good perennial weed control with minimal damage to the ferns (Estabrooks 1989). Harvest and storage

Fiddleheads are harvested by hand by cutting or breaking the fronds before they are 15 cm tall. Repeated harvesting of all fiddleheads will kill the plants. Studies have shown that where harvesting pressure is not severe, fiddleheads are larger and more succulent. It is advisable to remove only a few fiddleheads from a given plant, allowing some leaves on each crown to develop (von Aderkas 1984). In experiments in New Brunswick (Estabrooks 1989), fiddlehead plants, after 3 years of establishment and during the first year of crop production, yielded 310–927 kg/ha. During the second crop year, the yield doubled. Experiments have been carried out to determine storage methods and shelf life of fresh fiddleheads (Hunter-Burley et al. 1989). Containers of fiddleheads, covered with produce wrap, remained in acceptable condition for up to 5 days in cold storage and 2 days at room temperature. Uncovered material kept well in cold storage, but spoilage increased rapidly at room temperature, lowering marketability to 75% within 2 days. Fiddleheads stored at 2°C and 80–90% humidity for 5 days remained marketable longer at room temperature than those not exposed to a cold treatment. Shelf life of fiddleheads is affected by leaf size, stem length, and maturity of leaves. Larger leaves (greater than 2 cm in diameter) stayed firm longer. Long petioles and overmature fronds lowered quality. Fiddleheads packed too wet became moldy, with an unpleasant odor. Commercial processing of fiddleheads is simple. The scales, which protect young fiddleheads, are removed by a rotary washer; the fiddleheads are boiled for a few minutes and then canned or frozen in cardboard packages. Processed fiddleheads are packed frozen in New Brunswick and in cans in Maine (von Aderkas 1984).

Example cultivars

No cultivars are available. Some Canadian garden catalogs sell ostrich fern as an ornamental plant, which can also be used for its edible young leaves in springtime.

Additional notes Fiddleheads have nutritional qualities comparable to asparagus. They are a good source of vitamins A and C, niacin, and riboflavin. They are high in potassium and low in sodium, making them suitable for people on low-sodium diets (Bushway et al. 1982). Statements appearing in the press that ostrich fern is carcinogenic resulted from a confusion of fiddleheads with bracken fern (Pteridium aquilinum (L.) Kuhn). Studies have shown that eastern bracken, which has been widely consumed in Japan and elsewhere, is carcinogenic whereas ostrich fern is not (von Aderkas 1984). A number of other ferns are collected from the wild and eaten in Canada (for example, Turner 1975; Schofield 1989), despite the fact that some of these are also considered poisonous. Those who collect wild ferns for their fiddleheads need to be certain of the identify of the material collected before consuming it.

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The ostrich fern has been considered to be nontoxic. However, in May 1994, a few cases of gastrointestinal illness were associated with eating raw or lightly cooked fiddlehead ferns in New York and western Canada. In the American outbreaks, the implicated ferns were eaten either raw or lightly cooked (sauteed, parboiled, and microwaved). In a similar outbreak in British Columbia in 1994, eating lightly cooked fiddleheads was also associated with gastrointestinal illness. Health Canada conducted studies and found no toxicity problems. Although a toxin has not been identified, because of concerns that the ferns might contain a heat-labile toxin, Health Canada issued a warning advising that fiddleheads be boiled for 15 min or steamed for 10–12 min before eating (Morgan et al. 1994; F. Iverson, personal communication; Internet at: http://biomed.nus.sg/MEDNEWS/oct94/7482_6.html). Generally cookbooks recommend a shorter time in boiling water; for example, Richardson (1990) suggests 5–7 min, and cautions against both undercooking and overcooking. Curiosities

Ostrich fern is so-named because of its large leaves, said to resemble the plumes of an ostrich. Fiddleheads were served at a feast hosted by the Indian Chief Chkondum, given to Champlain when he reached the mouth of the Saint John River, N.B. (Seabrook 1973). In 1783 in New Brunswick, United Empire Loyalists were poorly prepared for their first winter and had to resort to eating ostrich fern. American Indians often ate fiddleheads in the belief that, when hunting, this would mask their scent (Schofield 1989). The ostrich fern has been called Canada’s “most renamed fern.” It has been variously placed in the genera Onoclea, Struthiopteris, Pteritis, and Matteucia (Cody and Britton 1989).

Problems and potential As noted above, deep planting and mulching improved the fiddlehead crop in experimental plots (Estabrooks 1989). One of the side effects was that greater plant density, although it improved early yield, increased fiddlehead blight, which is the only disease of economic importance. Improved air circulation decreased the amount of disease and may be the way to overcome the problem. Ostrich fern is the only native Canadian plant that has reached some commercial success as a vegetable. (Wild rice, Zizania aquatica L., another notable success, is considered more a cereal [Canada’s only native cereal] than a vegetable.) Frozen fiddleheads are available commercially and local supermarkets often supply fresh fiddleheads in season. Some experimental work has been done on ostrich fern to test it as a farm crop grown in fields. There is potential for increased use of fiddleheads as more consumers become familiar with the vegetable. Already demand exceeds supply of the frozen product, and the market has expanded beyond the Maritime Provinces


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in Canada (von Aderkas 1984). Major limitations are the short season of availability, along with ineffective harvesting because the plants are inaccessible, and difficulty in attracting labor. There is considerable potential for increasing quality and other desired characteristics, both by selection and development of management techniques. A necessary step is the development of mass propagation of ostrich fern, perhaps by tissue culture. A means of rapidly increasing populations is essential for improving the fiddlehead industry in Canada.

Selected references Estabrooks 1989; Hunter-Burley et al. 1989; Richardson 1990.

Medicago Alfalfa Leguminosae (Fabaceae) Pea family Légumineuses, famille du pois

Genus notes Eighty-six species are currently recognized in the genus Medicago (Small and Jomphe 1989), including annuals, biennials, and perennials. The genus is native to Europe, Asia, and northern Africa, although several species have been spread to other continents as weeds and as cultigens. In addition to M. sativa, discussed below, cultivars of several annual species (known as medics or medicks) have been selected for forage, especially in Australia, including M. truncatula Gaertn. (barrel medic), M. littoralis Rohde ex. Lois. (strand medic), M. italica (Miller) Fiori (disc medic), M. rugosa Desr. (gama medic), and M. scutellata (L.) Miller (snail medic). None of these annuals is grown in Canada, although medics are sometimes grown in the southern United States. Also, forage cultivars have been selected of the annual/biennial M. lupulina L., which is occasionally cultivated in Canada and shows promise as a weed-suppressing ground cover. The wild perennial shrub M. arborea (tree alfalfa, tree medic) is also sometimes planted for browse, fodder, and forage for livestock. However, it is mainly cultivated as an ornamental. The hard, dark wood of old plants of M. arborea have been used for saber handles, canes, and beads. This species is hardy to –10°C, so it could be grown in the warmest regions of British Columbia. Several wild annuals, for which cultivars have not been selected, are also cultivated for forage in hot, dry areas of the world. Several wild annuals are sometimes cultivated as garden ornamentals, most notably snail medic (mentioned above) and hedgehogs (M. intertexta (L.) Mill.). The annual species have good potential as green manure components of sustainable agricultural systems in North America. They are also sometimes used as ground cover. Curiously, the earliest documented use of the alfalfa genus was as human food. Flannery (1969) described evidence that in a southwestern Iranian farming village dated 7500–5600 B.C., wild alfalfa (likely annual Medicago) seeds were consumed, probably in a mixed gruel, and possibly also wild alfalfa stems. He noted that the high-protein wild legumes collected locally probably contributed to a diet better than that available in modern Iranian villages. Hedrick (1972) recorded the use of M. polymorpha L. as a vegetable by the Chinese, of the seeds of M. lupulina as a food by North American Indians, and of the leaves of M. platycarpa (L.) Trautv. in Siberia. The following treatment is rather extensive for what is presently a very minor vegetable. However, as will be noted, alfalfa is the most

Medicago (alfalfa)

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efficient source of protein that can be grown in most of the temperate world. Moreover, it is becoming painfully clear that much of the world can no longer afford the inefficiency of converting plants to meat. Alfalfa protein has more potential for alleviating world hunger and concomitantly reducing the ecological costs of agriculture than any other plant we are familiar with. Alfalfa sprouts could be the tip of an agricultural revolution.

Names Scientific (Latin) name: Medicago sativa L. English common name: alfalfa Also: lucerne French common name: luzerne (f) [Alfalfa sprouts germes de luzerne, pousses de luzerne (f)] The name lucern(e) is commonly used in all European countries east of Spain, and also in South Africa, New Zealand, Australia, and Oceania; the name alfalfa is employed in North and South America, and in Iberia.

Description and taxonomy Medicago sativa is a perennial, able to live 30 years or more under favorable conditions. Each spring the shoots arise from a crown situated on a vigorous root system that sometimes penetrates to a depth of 9 m. Tap and fibrous root systems occur in different forms. Rhizomatous-rooted variants spread by horizontal stems about ground level. Creeping-rooted types spread from underground stems and are especially persistent under adverse conditions such as extreme cold and trampling by livestock. Root nodules are present on the roots of Medicago, and the bacteria in these (Rhizobium meliloti Dangeard) fix atmospheric nitrogen, which is made available to the plants. Medicago sativa includes diverse forms, which are often recognized as separate species (Small and Brookes 1984). The principal variants that are cultivated include the following: M. sativa subsp. sativa (purple-flowered) M. sativa subsp. falcata (L.) Arcangeli (= M. falcata L., yellow-flowered) forms intermediate between these and assigned to M. sativa subsp. ×varia (Martyn) Arcangeli (= M. media Pers.; flowers variegated purple and yellow). Several taxa besides those mentioned above have also been recognized (Small and Jomphe 1989).

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These subspecies of M. sativa contain both wild and domesticated plants, although in many cases it is not possible to distinguish whether a plant is wild or domesticated. Wild forms of M. sativa are found in North Africa and Eurasia. As a ruderal weed and as an escape from cultivation, M. sativa occurs in all provinces of Canada. Medicago sativa subsp. sativa seems to have first been selected in eastern Turkey and Iran. Considered to be the oldest cultivated forage plant, it may have been first cultivated more than 5000 years ago. In its native habitat it is adapted to a continental climate with cold winters and hot, dry summers, low humidity, intense sunshine, high day temperatures, and cool nights. Its native soils have high pH values and are rich in basic compounds, and moisture is available, often at deep levels. By contrast, M. sativa subsp. falcata is found wild over much the same area as subsp. sativa but seems to be native further to the north in Siberia. It is a variant of upland areas, colder, more-humid climates, and leached acid soils. By comparison with subsp. sativa, it has better resistance to cold, physiological tolerance of relatively acid soils, and tolerance to diseases common in humid areas. However, subsp. falcata is much less tolerant of grazing and harvesting than subsp. sativa. Hybridization of the two subspecies (to produce subsp. ×varia) has resulted in forms that combine the desirable characteristics of both subspecies. This tolerance to a range of conditions has been the basis of the hardy cultivars that perform well in the climates and soils of Canada. Beginning in 1858, a German immigrant to Minnesota, Wendelin Grimm, began breeding a hybrid alfalfa combining falcata and sativa germplasm. The result, Grimm alfalfa, was the first type of alfalfa that proved able to survive winterkill in the northern United States and Canada. Grimm alfalfa was introduced to western Canada in 1908, marking the first successful establishment of alfalfa that could tolerate the severe cold. In eastern Canada in the late 19th century, a similar form known as “Ontario variegated” seems also to have played a role in bringing alfalfa cultivation to Canada. Today, most cultivars grown in Canada trace much of their ancestry to subsp. sativa, but there is usually also some parentage of subsp. falcata. One Canadian form, Anik, is derived only from subsp. falcata and is the most winter-hardy of all cultivars. The use of alfalfa as a vegetable is not extensive, although in the present century young growth of established plants has been used as food in China, in other parts of Asia, and in South Africa (Fox and Wilson 1937). Alfalfa is grown in Canada mainly as forage and fodder for livestock. Its present use as a vegetable is confined to the seeds, which are sprouted for consumption. Legume and cereal seeds have been sprouted for animal consumption for a considerable period, but the popular use of any seeds other than mung bean for sprouts for human consumption is largely a 20th-century phenomenon. The treatment that follows emphasizes the production of seeds in Canada.

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Uses Fresh alfalfa sprouts are now commonly available in supermarkets and are widely considered to be an excellent gourmet food. They are also considered to be a healthful food, furnishing significant amounts of minerals, protein, and the vitamins thiamine, riboflavin, niacin, and ascorbic acid (Hesterman et al. 1981). Alfalfa sprouts are rapidly increasing in popularity for use in salads and sandwiches. Aside from the use of alfalfa sprouts, there have been efforts to use mature plants, or at least the young leaves of alfalfa plants, for food. Bolton (1962) and Altinok and Jannasch (1991) reviewed attempts to incorporate alfalfa into various dishes. Haggart (1916) and Stramesi and Falabella (1943) made extensive tests of how to use alfalfa (mostly the young leaves) as a vegetable. Duke (1986) noted the use of alfalfa to prepare tea, by North American Amerindians, after its introduction to the New World. For animal feed, dehydrated alfalfa products have been developed. Cubes and pellets are factory-produced, condensed forms of alfalfa that are easily transported and stored and provide a long-lasting product with considerable protein, vitamins, and minerals. As well as being provided to horses, cattle, and sheep, they are also employed in rations for other domestic animals, such as rabbits. Another development in alfalfa technology is the production of leaf protein concentrate, involving the extraction of protein from the juice of green plant material. The subject is under exploration, but one day alfalfa protein may be incorporated in various foods in the human diet. Still other uses of alfalfa are as a component of seed mixtures for stabilizing slopes and providing ground cover, and as a green manure that considerably improves soil aeration (by its deeply penetrating roots) and soil nitrogen content. Example recipes

Alfalfa cream soup (Bolton 1962) Alfalfa croquettes (Bolton 1962) Alfalfa hamburger (Altinok and Jannasch 1991) Alfalfa pizza (Altinok and Jannasch 1991) Alfalfa pudding (Bolton 1962) Alfalfa soufflé (Bolton 1962) Alfalfa sauté (Altinok and Jannasch 1991) Alfalfa tortilla (Bolton 1962) Fresh alfalfa salad (Altinok and Jannasch 1991) Mashed alfalfa (Altinok and Jannasch 1991)

Importance Alfalfa is the “Queen of forages” and the “King of fodders.” It is considered to be the most widely adapted agronomic crop, the most energy-efficient crop to grow, and the most important source of protein yield per hectare (Barnes et al. 1988). It is grown mainly in the temperate regions of the world, with the United States, the

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Commonwealth of Independent States (CIS, formerly USSR), and Argentina providing about 70% of world hectarage, with France, Italy, Canada, and Australia accounting for another 20%. It is the principal hay plant in the United States (Hintz 1983) and the most important forage legume of Canada (Goplen et al. 1982) and the CIS (Michaud et al. 1988). More than 10 million ha of alfalfa hay are harvested annually in the United States and about 2 million hectares annually in Canada (Rumbaugh 1991). In Canada, an additional estimated 2–3 million hectares are used for pasture (particularly in mixtures). Alfalfa is grown in all provinces of Canada, with heavy concentration in both the East and the West. Most of the Canadian crop is used as baled hay, with some employed as silage and pasture. Statistics seem unavailable on the production and use of alfalfa for sprouts in Canada. In the United States, annual consumption of alfalfa seed for sprouts in the early 1980s was of the order of 3200 t, with a farm value of about American $63 million (Bass et al. 1988). This amount represented about 7% of the alfalfa seeds produced in the United States.


Particular cultivars are available that are suited to given soils. In general, alfalfa thrives on deep, well-drained, and near-neutral soils. It does not grow well on strongly acid soils but will tolerate slightly to moderately saline conditions. Cultivars with appreciable falcata germplasm generally survive better on acidic soils than those with only sativa parentage. Alfalfa will not survive prolonged poor drainage. It responds well to irrigation and also does well in droughty conditions on soils where the roots can penetrate to the water table, which may be as much as 5 m below the soil surface. In some areas of western Canada, alfalfa is irrigated. Alfalfa roots usually have nodules containing the bacterium Rhizobium meliloti, which fixes atmospheric nitrogen. If soils have not been used for growing alfalfa, they may lack sufficient bacteria, and, in establishing a new plantation, it may be necessary to add a bacterial culture to the seeds. The rhizobia are responsible for alfalfa’s ability to grow in soil with limited availability of nitrogen, and in fact to considerably improve the nitrogen content of the soil for other crops used in rotation.

Climate

Alfalfa is adapted to diverse climates; particular cultivars are adapted to given regions of Canada. Winterkill is a regular problem with alfalfa in colder areas. Cultivars show great differences in their ability to survive cold; those with falcata parentage tend to be adapted to colder regions than those with only sativa parentage. The most winter-hardy alfalfa of Canada is Anik, with exclusively falcata parentage.


Although alfalfa is a perennial, alfalfa pastures lose their vigor after about 5 years in Canada and therefore must be periodically replanted from seed. Because the crop arises each year from perennial shoots, pollination and pollinators are not required in most years. Alfalfa is

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mostly an outcrosser, pollinated by bees, so bee pollination is critical for the production of seeds, and therefore ultimately for the forage crop and for the production of alfalfa sprouts. In other parts of the world, honeybees are reasonable pollinators of alfalfa, and for much of the present century, most of Canada’s alfalfa seed came from honeybee-pollinated alfalfa grown in California. However, the honeybee is virtually useless as a pollinator in Canada, while another bee, the alfalfa leafcutter bee (Megachile rotundata (F.)) has proven exceptionally useful. In the past, native pollinators were sufficient to produce reasonable yields of alfalfa seed in Canada, but for various reasons native pollinators are unable to produce good yields of alfalfa seeds. In Canada, attempts to use leafcutter bees for producing alfalfa seed began in 1961 in southern Alberta. Since then there has been a steady expansion of not only the alfalfa seed industry but also an industry producing the leafcutter bees. The Canadian alfalfa seed industry is now centred in the West, and, as a result, western Canada no longer imports alfalfa seed, although seed is still imported in the East. The alfalfa leafcutter bee is normally solitary but readily accepts man-made shelters. For production of alfalfa seeds, shelters with about 50 000 bees per hectare are provided on irrigated land, and about 40 000 bees per hectare on nonirrigated land. Seed yields of 300–900 kg/ha have been attained under irrigation in the southern prairie region, and 150–300 kg/ha without irrigation. Most domestic alfalfa seed production in Canada is in the three Prairie Provinces, with some in British Columbia. Extensive information on the use of the alfalfa leafcutter bee to produce alfalfa seed is given in Richards (1984). Extensive information on cultural practices to raise alfalfa seed is given in Rincker et al. (1988). Production of alfalfa sprouts

As reviewed by Hesterman and Teuber (1979), Hesterman et al. (1981), and Bass et al. (1988), commercial cultural practices for producing alfalfa sprouts are quite diverse. In all cases, sprouts are grown in a controlled environment, without added soil or nutrients. There are two principal commercial methods. First, seeds may be placed in large tubs, flooded with water and drained several times each day, and the sprouts harvested and transferred to plastic bags for marketing after a few days. Second, sprouts may be germinated in drained plastic trays, watered by overhead sprinklers, and when ready, covered with a plastic lid and marketed in the same tray. Recommended optimum temperatures range from 16 to 27°C, and recommended sprouting times range from 1 to 6 days (or when the sprout is 1–5 cm long). A maximum fresh-weight yield of marketable sprouts has been achieved with a 6-day growing period (Bass et al. 1988). Hesterman and Teuber (1981) noted that conditions of temperature, light duration, quantity of Alfalfa sprouts

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water applied, frequency of adding water, and number of days to harvest differ somewhat depending on whether the objective is to produce alfalfa sprouts of highest nutritional quality or of highest fresh weight. For home production of alfalfa sprouts the following steps are recommended (Huxley et al. 1992): germinate the seed in moist, dark conditions at 16–20°C, rinse daily, and consume at 4–6 days as green shoots appear. A proportion of seeds of alfalfa are “hard” and will not germinate when moisture is supplied, because the hard seed coat remains impermeable to water. This characteristic presents a major difficulty when the goal is to produce alfalfa sprouts. To overcome the problem, the seed may be scarified (abraded) by various measures. Harvest and storage

In Canada, one cut of alfalfa is harvested in drier areas and up to four cuts in moister, longer-season regions. In the Prairie Provinces, alfalfa is usually harvested once or twice each year, whereas in the moister areas of British Columbia, Ontario, Quebec, and the Atlantic Provinces three or four cuts are possible. In warmer climates than in Canada, as many as 12 cuts may be taken in a year. Although used for pasturage and silage, alfalfa is mainly employed as hay. The highest content of protein occurs at about the 10% blooming stage, at which time the leaves have about 25% protein and the stem about 10%, and harvesting is recommended. To use alfalfa as a source of vegetable protein, this same harvesting regime could be followed. To use alfalfa shoots and leaves as a vegetable, slightly earlier harvesting, when flower bud initiation has just started, is preferable, as the plants will be slightly more tender. When grown for seeds, a single crop is harvested annually in Canada. Rincker et al. discussed methods of harvesting the seed. Bass et al. (1988) discussed methods of treating and storing alfalfa seeds.

Example cultivars

Canadian alfalfa cultivars are licensed on the basis of performance with respect to yield, winterhardiness, disease and insect resistance, and other agronomic characters. Few cultivars are appropriate for all regions of the country, so regionally adapted varieties are recommended. Each province or region of Canada annually updates a list of recommended cultivars, and most of these will produce satisfactory alfalfa sprouts. For growing sprouts, the cultivar selected can be quite important. Seed characteristics important in sprouting are high percentage germination, low percentage hard seed, and high seedling vigor (Hesterman and Teuber 1981). As reviewed by Hesterman et al. (1981), alfalfa cultivars may differ in temperature that produces the highest percent germination. There is some evidence that winter-hardy (“dormant”) cultivars take longer to germinate and have a lower percent germination than nonhardy (nondormant) cultivars (which are not grown in Canada). Moreover, heavier-seeded cultivars may produce more vigorous seedlings than light-seeded cultivars. Recommendations for specific cultivars appropriate for producing sprouts do not seem to be available.

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Additional notes Bloat is a digestive disturbance characterized by an abnormal distension of the abdomen caused by accumulated gases in the rumen of cud-chewing animals. Bloat occurs when the animal fails to eructate (belch) the accumulated gas. Alfalfa is notorious for causing bloat in ruminant animals, which may die. The fear of bloat limits use of alfalfa as pasturage. The problem is reduced by growing alfalfa in mixtures with grasses, and by never turning hungry animals loose on lush stands of bloat-causing legumes. Considerable research intended to produce a bloat-safe alfalfa is in progress in Canada. Man, like other monogastric animals, is not subject to this type of bloat. Another veterinary problem associated with alfalfa is the presence of a class of antinutritional chemicals called hemolytic saponins (Small 1992; Small et al. 1990). In this case, it is monogastric animals that are susceptible, while ruminants are immune. Alfalfa saponins are very detrimental to poultry and fish, and somewhat harmful to swine and some other monogastric animals. Normally, about 1% saponin occurs in the leaves of most cultivars of alfalfa grown in Canada (higher levels are encountered in the falcata lineage than in the sativa lineage). However, extremely high levels of hemolytic saponin occur in alfalfa sprouts (up to 8%), commonly bought at the supermarket for salads. Nevertheless, research has shown that ingested alfalfa hemolytic saponins normally do not get directly into the bloodstream, and there is no evidence of harmful effects in humans. Because of the antinutritional effects, and suspicion that there just might be undiscovered undesirable effects on humans and livestock, some varieties of alfalfa with low levels of saponins have been bred. In any event, it is possible that alfalfa saponins may actually be healthful. Alfalfa saponins reduce levels of blood serum cholesterol in animals, which is considered good for people, because elevated cholesterol levels clog arteries and can lead to heart attacks. Indeed, saponins are a common constituent of many herbal tonics, although the usefulness of these remains to be demonstrated. Canavanine, a toxin present in alfalfa sprouts, has caused anemia in monkeys (Bass et al. 1988) but has not aroused much concern to date as a potential health hazard to humans. A pathogenic bacterium (Klebsiella pneumononiae (Schroeter) Trevisan) has been found on alfalfa sprouts from a few American retail outlets and has been thought to pose a potential health hazard for people with low resistance to the bacterium who consume large quantities of alfalfa sprouts (Bass et al. 1988). Curiosities

It has been suggested that the grass eaten by the Chaldean king of Babylon Nebuchadnezzar (605–562 B.C.), when he was driven into the fields, was actually alfalfa. The discovery of the Americas and their colonization by Portuguese and Spaniards in the 16th century led to the introduction of alfalfa into Mexico and Peru (Michaud et al. 1988). It has been said that, when Cortez and Pizarro completed their

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conquests of Mexico and Peru, the natives of the New World had alfalfa in lieu of their gold. Because of the presence of Chilean gold seekers at the time of the California gold rush, when alfalfa was growing in popularity, alfalfa came to be known as Chilean clover in the western United States. Alfalfa flowers are explosive, slapping visiting pollinators violently with the sexual parts of the flower to dust pollen on the insects and pick up pollen that they are carrying. Some insects have been observed trapped to death between the sexual organs and petals of the flowers. Record yields for alfalfa in North America (single crop, wet weight) are 22 t/ha (10 tons/acre) without irrigation and 54 t/ha (24 tons/acre) with irrigation. It has been estimated that 80 million flowers per hectare can be produced by alfalfa. “Alfalfa” is a secret language used by some youngsters, like Pig Latin, to avoid being understood by parents and teachers. To talk alfalfa, you insert the syllables of the word alfalfa between the syllables of whatever is being said. “Better late than never” comes out “Betalterfal latefa thanal nefalverfa.”

Problems and potential The amount of alfalfa grown for forage, silage, and pasture in Canada is huge and fairly stable. By contrast, alfalfa for sprouts has potential for increase, as consumers become more health conscious. Perhaps the most exciting possibilities for increasing alfalfa cultivation in Canada lie in its remarkably high protein content (about 2 t/ha). Commercial demand for proteins is growing rapidly. In experimental work at Sainte-Foy Research Station, Agriculture and Agri-Food Canada, specialized protein genes have been inserted into alfalfa, resulting in large quantities of the desired speciality protein being produced. As agricultural land is converted to urban purposes, the efficiency of protein production of alfalfa for feeding not only animals but also humans will become extremely significant for addressing both the world’s hunger problem and the technological development of new foods from basic plant constituents. As the world’s most efficient protein-producing crop, humans may one day turn to alfalfa directly for the bulk of their protein diet, rather than relying on first converting plant protein into meat from domestic animals.

Selected references Hesterman and Teuber 1979; Lesins and Lesin 1979; Hanson et al. 1988.

Momordica Bitter melon Cucurbitaceae Gourd family Cucurbitacées, famille de la courge

Genus notes Mormordica is made up of about 42 species of herbaceous vines, native to the Old World tropics. The following three species are cultivated: M. charantia, which is discussed below; M. cochinchinensis (Lour.) Spreng., spiny bitter cucumber, cultivated in south and east Asia; and M. cymbalaria Hooker fil., also used in Asia (Bailey and Bailey 1976, Jeffrey 1980).

Names Scientific (Latin) name: Momordica charantia L. English common name: bitter melon Also: balsam pear, bitter cucumber, karela (kerala), maiden’s blush, leprosy gourd, Chinese bitter melon, fu kwa, nigai uri, ampalaya French common name: margose (m) (Grisvard et al. 1964) When not cultivated for food, the species is known as momordique à feuilles de vigne and poire de merveille (Grisvard et al. 1964).

Description and taxonomy Bitter melon is a fast-growing, trailing or climbing vine with thin stems and tendrils. Male and female flowers are borne separately on the same plant, singly in the leaf axils, and require insects for pollination. Male flowers appear first and usually exceed the number of female flowers by about 25 to 1. The flower opens at sunrise and remain open for only 1 day. The fruits have a pebbly surface of smooth warts and smooth lengthwise ridges. Immature fruits are light green, oblong, pointed at the blossom end and have white flesh. As the fruits begins to mature, the surface gradually turns yellow or orange. At maturity, they tend to split open, revealing orange flesh and a bright red placenta to which the seeds are attached. Seeds are tan and oval, with a rough etched surface. The area of origin of this annual herbaceous plant is unknown, although India is considered to be the centre of diversity (Tindall

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1983). The cultigen is subsp. charantia (Schultze-Motel 1986). It was brought to Brazil in the 17th or 18th century, possibly from Africa. The plant is now cultivated throughout southeast Asia, China, and the Caribbean. It has become a serious weed of citrus groves in Florida. The wild phase is subsp. abbreviata (Ser.) Grebensc. (Schultze-Motel 1986). (This phase is var. abbreviata Ser. of some authors [Walters and Decker-Walters 1988]). This native of Asia is the presumed progenitor of the domesticate.

Uses In North America, bitter melon is grown entirely for its immature fruits, which are used in oriental cooking; however, in some countries, the young leaves are also harvested and used as a potherb. The immature fruits are a source of vitamin C and provide some vitamin A, phosphorus, and iron. The tender vine tips are a source of vitamin A. The bitter flavor in both the fruits and leaves is due to the alkaloid morodicine, which can be reduced somewhat by parboiling or soaking in salt water. Immature fruits are least bitter; ripe fruits are extremely bitter and have been reported to be toxic to man and animals. As a vegetable, immature fruits are boiled or fried, often after steeping in salt water (with the peel removed) to eliminate the bitter taste. The fruits are also used in curries and pickles. The tender young shoots and leaves are parboiled to leach out the bitterness before being eaten. They should be boiled in two changes of water. Many consider the stems too wiry to eat, but the leaves are tender (Morton 1967; Heiser 1979; Tindall 1983; Yamaguchi 1983; Walters and Decker-Walters 1988). When mature, the fruits turn orange and yellow and split open, revealing scarlet arils covering the seeds (an aril is a fleshy growth covering some seeds). The sweet arils are eaten by humans and birds. Example recipe

Baked balsam pear with shrimp (Buishand et al. 1986)

Importance Bitter melon is predominantly a third-world subsistence crop (Huyskens et al. 1992). It is widely grown in China and India and throughout Southeast Asia, but is also grown in small acreages in the United States, primarily in California and Florida. In tropical countries an average yield is 8–10 t/ha, and optimal yields of 15 t/ha are possible (Tindall 1983). It is exported to Europe from tropical countries. In 1985 the United States imported 1263 t of bitter melon from the Dominican Republic (Lamberts 1990). In Canada, bitter melon is currently grown only in home gardens.

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Maximum yields are produced in soils with high organic matter content and good water-retaining capacity. A deep, well-drained sandy loam or silt loam is ideal. Light sandy soils will warm up sooner, which is an advantage for growing hot-climate crops in Canada. Heavy clay soils retain more moisture, but are cooler and do not drain as well as lighter soils.

Climate

Optimum germination occurs at temperatures of 25–35°C, and no germination occurs below 12°C. Irrigation is required during dry periods (Tindall 1983). Successful irrigation practices for squash, cucumbers, or muskmelons are appropriate for bitter melon. Bitter melon grows well in the warm temperatures that are preferred by squash. Frost may kill the plants and cool temperatures will retard development. Bitter melon is normally grown as an annual crop, but can perform as a perennial in areas with mild winters.


Propagation is by seeds sown indoors and transplanted after danger of frost is past. Seeds should be planted about 1.2 cm deep. When planted in warm soil, seedlings will emerge in a week or less. Transplantation should be done by a method that avoids disturbance of the root system; bare-root plants will not survive well. Bitter melon is usually grown on trellises 1–2 m tall (Tindall 1983). Experiments in Israel (Huyskens et al. 1992) showed that yield was higher and harvesting time shorter when plants were allowed to trail across the ground.

Harvest and storage

Young fruits should be harvested 8 to 10 days after flower opening while they are still firm and light green and the pulp and seeds are soft and white. The fruits will be 10 to 15 cm in length, 3.8 to 6.4 cm in diameter (depending on variety), and will weigh 85 to 113 g. Beyond this stage, fruits become spongy and more bitter. The development of mature fruits on the plants may reduce setting of new fruits, so harvesting should be fairly frequent. A good yield is 10 to 12 fruits per plant. Storage recommendations are 12 to 13°C at 85 to 90% relative humidity, with an approximate storage life of 2 to 3 weeks. The fruits should be handled with care to avoid abrasions. In commercial practice they may be isolated in storage from fruits that produce large amounts of ethylene to avoid postharvest ripening.

Example cultivar

Foo Gwa. Many cultivars are available, varying in fruit size and shape, earliness, yield, fruit quality, and disease resistance, but little is known regarding their comparative performance in either Canada or the United States. Bettencourt and Konopka (1990) listed institutions in various countries conserving bitter melon germplasm.

Additional notes Bitter melon has been used as a folk medicine in parts of Asia. The fruits, seeds, and roots are reported to contain compounds with

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pharmaceutical effects, including a substance with the clinical properties of insulin (Jeffrey 1980; Huyskens et al. 1992). Molecules with insulinlike activity have been found in both the fruits and seeds. In human experiments, the fruit juice was found to improve significantly the glucose tolerance of 73% of patients when given orally (Ng et al. 1986; Welihinda et al. 1986). Toxic effects are associated with ingestion of large doses of the ripe fruits. It is a purgative and abortifacient. Ingestion of mature fruits has been implicated in cases of poisoning of dogs. Alleged anti-HIV activity of bitter melon has led to self-medication by many individuals. Its use in folk medicine is considered dangerous (Morton 1967; Heiser 1979). Curiosities

The fruit pulp has been mashed and mixed with olive oil for use as a linament for piles, burns, and chapped hands. The fruit juice has been given as a substitute for quinine and also used as a vermifuge and remedy for liver and spleen ailments (Morton 1967; Grieve 1978). The vine is used in folk medicine more extensively than the fruits, both as a “blood tonic” and in the treatment of malaria, colds, liver complaints, and kidney stones (Morton 1967). In Columbia and Cuba the fruits have been used as a substitute for soap to wash clothes (Morton 1967). One common name for this plant is “leprosy gourd,” because of its use in the Orient for the treatment of leprosy (Heiser 1979).

Problems and potential Bitter melon is unfamiliar to most Canadians and is likely to remain a novelty of home gardens. It is basically a tropical plant adapted to warmer climates than found in Canada.

Selected references Heiser 1979; Tindall 1983; Walters and Decker-Walters 1988; Huyskens et al. 1992.

Montia Winter purslane Portulacaceae Purslane family Portulacacées, famille du pourpier

Genus notes Montia consists of about 50 species of annual or perennial herbaceous plants native mostly to North America, with a few in Eurasia and Australia (Bailey and Bailey 1976). Depending on the authority, some North American members of this genus are often included in the genus Claytonia. In addition to M. perfoliata discussed below, edible leaves are sometimes collected from M. sibirica (L.) Howell [= Claytonia sibirica L.]), a native of western North America.

Names Scientific (Latin) name: Montia perfoliata (Donn) Howell Frequent scientific synonym: Claytonia perfoliata Donn English common name: winter purslane Also: miner’s lettuce, Cuban spinach French common name: pourpier d’hiver (m) Also: claytone de Cuba (Schultze-Motel 1986)

Description and taxonomy Winter purslane is an annual herbaceous plant growing in open to shady, moist, sandy woods. It is native to western North America from British Columbia to Mexico (Scoggan 1978–1979). Cultivated plants are essentially unchanged from those found in the wild. A form with small stature has been named forma parviflora (Dougl.) Howell (Bailey and Bailey 1976). Native Americans, Spanish colonists, and settlers in California ate the leaves of winter purslane, both raw and cooked (Szczawinski and Turner 1978). Winter purslane now grows wild in western Europe, where it has been introduced, and it is cultivated in several European countries (Buishand et al. 1986).

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Uses Winter purslane can be used raw in salads. It is also boiled for 2–3 min and served like spinach (Szczawinski and Turner 1978). Some consider its flavor reminiscent of water chestnut. Example recipes

Miner’s lettuce with parmesan (Szczawinski and Turner 1978) Miner’s supreme, French style (Szczawinski and Turner 1978) Winter purslane soup (Buishand et al. 1986)

Importance Winter purslane is cultivated as a minor crop in western Europe, including Britain, France, Belgium, Germany, and The Netherlands (Buishand et al. 1986). No reports seem available on its use in Canada, where it is a very minor vegetable.


Winter purslane grows in moist sandy soils and waste places in its native habitat (Szczawinski and Turner 1978). In gardens, a sandy loam rich in organic matter would be beneficial.

Climate

The species grows in sunny to slightly shaded locations. Winter purslane is best cultivated in the cooler spring and late summer to promote leaf growth. It requires a regular supply of moisture.


Winter purslane is propagated by seeds, which are sown in early spring for early summer harvest or in late summer for an autumn harvest (Buishand et al. 1986).

Harvest and storage

The leaves and stems are picked before the plant starts to flower (Szczawinski and Turner 1978). Winter purslane will store for 1–2 days in a refrigerator (Buishand et al. 1986).

Cultivars

Cultivars are unavailable in Canada. Winter purslane is occasionally sold in Canadian garden catalogs as “winter purslane” or “miner’s lettuce.”


The common name “miner’s lettuce” refers to the use of the leaves by prospectors and miners as a salad green during the time of the California gold rush.

Problems and potential Winter purslane is a very minor vegetable with little potential for increased use.

Selected reference Szczawinski and Turner 1978.

Nasturtium Watercress Cruciferae (Brassicaceae) Mustard family Crucifères, famille de la moutarde

Genus notes “Nasturtium” as a common name refers to species of the South American genus Tropaeolum, not to species designated by the scientific name Nasturtium. This curious transfer came about through the similar taste of the leaves, flowers, and fruits of Nasturtium and Tropaeolum, as the popularity of growing the latter in flower gardens increased (Fernald et al. 1958). Nasturtium consists of six species of perennial, herbaceous, temperate region plants adapted to water or wet soils (Bailey and Bailey 1976). One species, N. officinale, is widely grown as a vegetable and is discussed below. Another species, N. microphyllum Boenn. ex Rchb. (= N. officinale var. microphyllum (Boenn.) Thell.), is also said to have been used as a salad plant collected from the wild. It hybridizes with N. officinale (Bailey and Bailey 1976).

Names Scientific (Latin) name: Nasturtium officinale R. Br. Frequent scientific synonym: Rorippa nasturtium-aquaticum (L.) Hayek Common English name: watercress Common French name: cresson de fontain (m) Also: cresson

Description and taxonomy Watercress is a perennial herbaceous plant adapted to wet soils and shallow water. In cultivation it is generally grown as an annual. Cultivated selections are essentially unchanged from the wild form. Watercress is native to Europe, northern Africa, and western Asia (Clapham et al. 1987). In Canada, it has been introduced in British Columbia and Alberta. Nasturtium microphyllum is found across southern Canada, and a hybrid between it and watercress occurs in Alberta and Nova Scotia (Scoggan 1978–1979).

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Watercress was used as a medicinal plant in Eurasia from the 1st to the 19th century A.D. It was also eaten and, in Ireland, was considered a royal tribute for the Kings of Erin. The plant appears to have been spread by man. The first widespread cultivation of watercress may have been in southern Germany, especially near Erfurt, as early as 1750 A.D. Large-scale cultivation in England began in 1808 to supply the London market and, in France, near Paris in 1811. In Germany and France, watercress was cultivated; in England, both watercress and the hybrid (known as brown cress) with N. microphyllum were grown (Simmonds 1976). More recently, cultivation of watercress has spread to many tropical and temperate regions. It has become a problem in some areas, such as in New Zealand, where it is a serious weed in rivers (Clapham et al. 1987).

Uses The leaves and young shoots of watercress are usually eaten raw in salads, employed as a garnish for meat dishes, added to soups, or eaten in sandwiches. It is also used as a cooked vegetable in southeast Asia (Tindall 1983). Example recipes

Baked potatoes with watercress and marigolds (Leggatt 1987) Chicken soup with watercress (Buishand et al. 1986) Green vegetable quenelles with mushroom cream (Levy 1987) Watercress and avocado salad (Richardson 1990) Watercress dressing (Richardson 1990) Watercress salad with goat cheese (Levy 1987) Watercress velouté soup with cheese puffs (Levy 1987)

Importance Watercress is commercially produced in several European countries, including Britain and France (Buishand et al. 1986). It is grown in California and the mid-Atlantic states in the United States (McCoy 1987). In Canada in 1991, 40 t of domestically grown and 1195 t of imported watercress were unloaded at 10 major Canadian markets (Anonymous 1992a); in 1992, 57 t of domestic watercress were unloaded in these markets (Anonymous 1993a).


Watercress grows naturally in very wet soils or in watercourses. A gravel substrate is often used in commercial operations. The pH should be 6.5–7.5 (Tindall 1983). The home gardener can grow watercress outdoors by digging a trench, lining it with plastic, and placing about 5 cm of sand and peatmoss on the bottom for the seeds. Alternatively, a wet, shaded soil is suitable. An unpolluted watercourse can also be used if it has

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quite shallow areas (Halpin 1978). In greenhouses and indoors, watercress is grown on a variety of substrates and lends itself to hydroponic gardening. Habegger et al. (1989) found that for watercress grown in submerged pots, mixtures of poorly and well-decomposed peat provided a good substrate. Climate

Watercress is a hardy, cool-season semi-aquatic that grows naturally in clear, cold, shallow, slow-moving streams. Accordingly commercial production generally uses beds in running water (natural or constructed) to provide required growing conditions. Greenhouses are also used for watercress production. Best temperatures for propagation of seed are 18–21°C, and for growth, water temperatures ideally are 10–12°C. A constant source of slow-running water is directed through the beds once seedlings are established. Watercress flowers when daylength is more than 12 h per day. Buds are usually pinched off to prevent flowering and to promote branching (Tindall 1983; Chadwick 1985). Trials in Britain have shown that watercress is damaged by frost and that use of a plastic tunnel is superior to submerging the plants, which injures and promotes yellowing of leaves (Rothwell and Robinson 1986).


Watercress is propagated by seeds or cuttings. Most commercial production employs seed for propagation to prevent the spread of vegetation-born viruses such as the turnip mosaic virus (Wainwright and Marsh 1986). Seeds are generally covered lightly with soil. The soil is misted to keep the seeds moist until germination. Running water is added after germination and the water level is increased to about 5 cm in depth, as the plants grow either floating or rooted to the bottom. Alternatively, cuttings are rooted in containers that are submerged in water. Partial shade should be provided (Tindall 1983). In commercial operations watercress is raised from seed and treated as an annual crop, generally in specially constructed beds. The beds can be side-by-side, or tiered with water flowing in at the high end and out the low end. In Britain the recommended flow-rate of water per 0.3 m width of bed is 720 L/h. The beds are traditionally 9 m wide and 48–70 m long. Nursery beds are used for seed propagation and the seedlings are transplanted to the water beds either by hand or by a modified rice planter (Chadwick 1985). Another method is to grow watercress in greenhouses either in beds or in pots. The advantage of using pots is that the plants are not cut at harvest time but are sold rooted in the pots, avoiding the quick withering and loss of quality of cut watercress. The pots can either be submerged in flowing or still water. Small-sized pots produce plants with thinner stems with a higher proportion of leaves and are more efficient for crop production (Habegger et al. 1989). Wainwright and Marsh (1986) noted that much of the seed used commercially in Britain is produced by the growers, who have little time to improve their seed stocks. Vegetative propagation of plants has the potential to improve watercress production. Lines can be cloned en masse to provide improved seed uniformity and quality, and clonal stock beds could be established as sources for

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propagation. Such procedures have been demonstrated to be commercially viable. Harvest and storage

In Europe commercial harvesting depends on the culture method. Watercress grown in beds is collected when it reaches a minimum height of 16 cm. Bunches with about 14-cm long stems are manually cut, tied together, and cut again to produce 8-cm long watercress that is packed in bulk for supermarkets. Mechanical bunching machines have been developed that require two operators and can produce 20 000 bunches per hour, as compared to a person cutting manually who produces only about 300 bunches per hour (Chadwick 1985). Watercress stores for 3–4 days at 0–1°C and high humidity. It is often sold in plastic bags, open to allow frequent spraying with cold water during shipment and display in stores (Tindall 1983; Buishand et al. 1986; McCoy 1987). Watercress is also grown and sold in small pots and flats. This method reduces loss of quality and increases storage time (Habegger et al. 1989). In the United States, commercial growers harvest plants in two ways. From March to October, when the air is warm and the crop grows above the water, the plants are cut and the stubble below water is allowed to regrow. When there is danger of frost the water level in the beds is raised to cover the plants. The crop actually grows best underwater in cold conditions, during which leaves and some plants are harvested, leaving as many as two-thirds of the plants intact. The roots are cut off plants that are harvested from plants grown either way, and the plants are bunched (McCoy 1987).

Cultivars

Canadian garden catalogs supply seeds for this crop under the names “true watercress” and “watercress.”

Additional notes Overuse of watercress can lead to kidney problems, and the undiluted juice can produce throat and stomach inflammations. Wild watercress has been reported as a source of liver fluke in humans, especially in areas frequented by livestock (Chadwick 1985). Curiosity

The generic name Nasturtium comes from the Latin nasus tortus, “a convulsed nose,” in reference to the mustard-oil taste characteristic of the genus (Fernald et al. 1958).

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Problems and potential Watercress is a minor crop in Canada. In 1991, domestic production of watercress was less than 5% of the total used in Canada. All the domestic watercress unloaded at major Canadian markets occurred during the summer growing season (Anonymous 1992a; see “Importance”), indicating that little watercress is grown in greenhouses during the winter months. There is potential for greenhouse or hydroponic production of this crop.

Selected references Yamaguchi 1983; Chadwick 1985; Small 1997.

Pastinaca Parsnip Umbelliferae (Apiaceae) Carrot family Ombellifères, famille de la carotte

Genus notes Pastinaca consists of about 14 species, native to Europe and Asia (Tutin 1968). One species, discussed below, is cultivated for its edible roots.

Names Scientific (Latin) name: Pastinaca sativa L. English common name: parsnip French common name: panais (m)

Description and taxonomy Parsnip is a biennial herbaceous plant that is grown as an annual. It occurs in both wild and domesticated forms (Tutin 1968). The domesticate is subsp. sativa. Although known in ancient Rome, parsnip was not domesticated until perhaps the 16th century, in central and southern Europe. The economically important part includes the true root and the upper hypocotyl (tissue between the true root and stem). Commercially the underground storage organ is referred to as a “root,” although as noted here this term is not strictly correct. In the following discussion, however, parsnips are referred to as roots, following conventional practice. Most parsnip roots are conical, long, slender, fleshy, succulent, and whitish or light brown. Parsnips may be more than 50 cm long, and 10 cm or more wide at the top. Parsnip is native to Europe and western Asia, where several wild forms occur, as follows: subsp. sylvestris (Miller) Rouy & Camus, the commonest form, has an angled stem and soft flexuous stem hairs; subsp. urens (Req. ex Godron) elak has a round stem and short hairs; subsp. divaricata (Desf.) Rouy & Camus has a round, gray, hairy stem and is restricted to parts of Europe. In Canada, wild parsnip is naturalized in all provinces and the Yukon Territory, most commonly in Ontario and Quebec (Scoggan

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1978–1979). Wild parsnip roots are wiry, tough, and much less palatable than roots of the domesticated parsnip. The wild parsnip has an undeserved reputation for being poisonous (contact with the foliage causes severe dermatitis in sensitive individuals, but most people can safely ingest the roots). However, the wild parsnip resembles several highly poisonous plants, such as the water hemlock (Cicuta), so it should not be eaten except by those who are skilled in its identification (see “Additional notes”). Many references state that the domesticated parsnip escapes easily to the wild and reverts to a wild form. This interpretation has not been examined experimentally and merits some skepticism. The wild parsnip in Canada is probably not a garden escape but an import from the Mediterranean area, like many other Canadian weeds.

Uses Parsnip roots, after being washed, are best left unpeeled to enhance retention of the sweet, nutty flavor. The roots are boiled, baked, or fried and used in vegetable dishes, meat dishes, soups, and stews (Buishand et al. 1986; Nonnecke 1989). Parsnips may be mashed like potatoes, glazed like sweet potatoes, pan-fried, creamed, or french-fried. Deep-fried parsnip chips are a flavorful alternative to french-fried potatoes. Aside from its food use for humans, parsnips are also sometimes used as a stock food. Example recipes

Baked parsnips with fruit (Morash 1982) Indian pakoras (Tudge 1980) Parsnip pie (dessert) (Morash 1982) Parsnip tart (Morash 1982) Parsnip wine (Grieve 1978) Parsnip–Soffritto soup (Morash 1982) Parsnip–pecan cake (Morash 1982) Sautéed parsnip slices (Morash 1982)

Importance The principal areas producing parsnip in Canada are British Columbia, Manitoba, Ontario, and the Atlantic Provinces, with most production in Ontario. Domestic production is responsible for most of Canadian parsnip consumption (Coleman et al. 1991).


A deep, rich, friable, well-aerated, stone-free soil is essential for long, well-formed roots. The soil should be free from clods, because hilling is required late in the season to prevent greening of the top of the parsnips (Nonnecke 1989) (see “Propagation and cultivation”).

Climate

Parsnip is a slow-growing cool-season vegetable. Optimum germination requires 14 days at 25°C. Parsnip foliage is harmed by a light frost (–1.5°C). When parsnips with roots 6 mm in diameter or

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larger are subjected to cold temperatures (below 10°C) for some time, flowering is initiated. Parsnip requires considerable water for good production (Anonymous 1988a). Propagation and cultivation

Freshly purchased seed should be used, because viability falls rapidly with age. Pelleted seed is employed for precision seeders. The seed is sown as early as the soil can be prepared. Because parsnip seed germinates slowly over 2 weeks and its growing season is long, the crop must be sown early. As with carrots, thinning of seedlings is essential to avoid intertwined, stunted roots. Soil moisture levels should be high to prevent soil crusting that inhibits seedling emergence. Late-seeded crops often burn off during the hotter dry weather (Anonymous 1988a). Cultivation should be kept to a minimum to avoid disturbing the roots. Hilling earth around the top of the roots near harvest reduces green shoulders on the roots of varieties susceptible to this problem. Seed production of parsnip was described by Simpson et al. (1985).

Harvest and storage

In Canada, commercial harvesting begins in mid September for the fresh market. A carrot harvester is used to undercut and pull mature parsnips. The tops are removed and the roots are washed in mild bleach and stored at 0°C and 90–95% humidity. Parsnips can remain in storage until the next year’s crop is ready, which provides a constant supply for markets (Nonnecke 1989). Home gardeners can overwinter parsnips in the earth. If the ground is covered to prevent freezing, the roots may be dug up all winter. Parsnips remain good for eating the following spring provided the plant has not begun to regrow. Against the use of parsnip is a lack of understanding of its maturation. In early fall the parsnip is of limited palatability, insipid, and floury rather than buttery in texture. The sweetness of the parsnip roots becomes well developed only after they are exposed to at least several weeks of cold temperatures. Roots should be left in the ground until freezing conditions prevail or stored under quite cool conditions (just above freezing) to convert the starches to sugar, which improves the flavor considerably.

Example cultivars

All American, Harris Model, Hollow Crown and Hollow Crown Improved. Hollow Crown is probably the leading cultivar grown in home gardens. It has roots that are often more than 30 cm long, decidedly tapered, thick-shouldered, with a conspicuously hollowed crown and a distinct core. Market gardeners usually use both long- and medium-rooted cultivars. Like carrots, short-rooted early cultivars can be used on heavy, clay soils, where the long-rooted kinds may become pronged. Bettencourt and Konopka (1990) listed institutions in various countries conserving parsnip germplasm. Facciola (1990) provided an extensive description of parsnip cultivars available in the United States.

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Additional notes Some individuals consuming the plant juices of parsnip can develop photodermatitis after exposure to sunlight. Leaves, stems, and roots can cause the problem. The edible roots contain enough furocoumarins to be physiologically active in some cases. These chemicals are potent photosensitizers and are mutagenic in long-wavelength ultraviolet light. Consumption of 0.1 kg of parsnip could expose a human to 4–5 mg of total psoralens. These toxins are mutagenic (even in the dark) inducing melanization in human skin. Photodermatitis from parsnip is often confused with poison-ivy dermatitis (Ivie et al. 1981). Most people consuming moderate amounts of parsnips need not be concerned with possible harmful effects, although clearly susceptible individuals should avoid this vegetable. Curiosities

Parsnips were held in such repute by the Roman Emperor Tiberius that he had them brought to Rome annually, from the banks of the Rhine (Grieve 1978). Some interesting uses of parsnip include an Irish cottage beer made by boiling the roots with water and hops, followed by fermentation; a marmalade preserve; and a wine that has quality said to approach the famed Malmsey of Madeira (Grieve 1978). Parsnip roots were purported to have some medicinal properties. During Medieval times it was written that it “nourisheth much and is good and wholesome, but a little windy, but it fatteneth the body if much used. It is good for the stomach and reins and proveketh urine” (Grieve 1978).

Problems and potential The parsnip is an old-fasioned vegetable with limited popularity today. Perhaps its chief drawback is that it develops slowly. Slow growth is characteristic of many of the common umbelliferous vegetables and herbs (carrot, turnip-rooted chervil, celeriac, celery, chervil, parsley, anise, caraway, coriander, dill, and fennel); of these, parsnip may be the slowest. As a long-season crop it is at a disadvantage with market-oriented growers, who can obtain two or more crops in a single season using other species. It ranks far below such root crops as carrot, beet, and turnip in demand. Parsnips are not a major crop, representing only about 0.1% of the total Canadian fresh fruit and vegetable industry. Most of the Canadian demand is supplied domestically (Coleman et al. 1991). Appreciable expansion of parsnip growing in Canada is unlikely unless an export market can be developed.


Petroselinum Turnip-rooted parsley Umbelliferae (Apiaceae) Carrot family Ombellifères, famille de la carotte

Genus notes Petroselinum consists of three Old World herbaceous species (Bailey and Bailey 1976). One of these furnishes the herb parsley discussed in the volume Culinary Herbs (Small 1997), as well as the vegetable turnip-rooted parsley discussed below. Petroselinum crispum (Mill.) Nym. ex A.W. Hill is a biennial or short-lived perennial that probably originated in southern Europe or western Asia. It is cultivated in parts of Europe, Asia, North and East Africa, and warmer parts of the New World. The two cultivated varieties are distinguished by the plant parts used. Schultze-Motel (1986) presented a formal hierarchical system of classification of the cultivar groups. Most other authors discussing P. crispum (e.g., Bailey and Bailey 1976) formally recognize the varieties but not additional categories. Variety crispum furnishes parsley, which has edible leaves and is used as a herb, garnish, and occasionally in vegetable dishes. Parsley is discussed in Culinary Herbs. Unlike var. tuberosum, discussed in detail below, the roots are thin and fibrous. Whether or not there are truly wild forms of P. crispum is not known, although some uncultivated plants are found in the wild (Simmonds 1976). Wild-growing forms in Europe or western Asia may represent a native distribution, whereas free-living plants in other areas, including North America, are commonly interpreted as escapes from cultivation. Plants are occasionally collected in the wild in Canada but are scarcely established here.

Names Scientific (Latin) name: Petroselinum crispum var. tuberosum (Bernh.) Crov. English common name: turnip-rooted parsley Also: Hamburg parsley, Dutch parsley, rooted parsley French common name: persil à grosse racine (m)

Description and taxonomy Turnip-rooted parsley is a biennial that is grown mostly as an annual, primarily for its edible, parsniplike, tapering, thick, dingy-white roots; the leaves can also be harvested like regular parsley (Bailey and

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Bailey 1976; Simmonds 1976). In mild climates it may be grown as a biennial, the taproot developing particularly strongly in the second season, provided that the flower stalks are removed promptly. This vegetable is often double-rooted. Turnip-rooted parsley is thought to be a relatively recent development, having apparently arisen no more than several hundred years ago. It was first mentioned in Germany in 1542 and may have been selected in Holland, because it was called “Dutch parsley” in early times. It was first recorded in England in 1726, and in American gardens in 1806 (Hedrick 1972).

Uses The flavor of turnip-rooted parsley is similar to both carrot and celery. It combines well with carrots, potatoes, turnips, and onions. Washed and (optionally) peeled turnip-rooted parsley roots can be grated and added to soups and stews (Halpin 1978). The cooked roots can be mashed, roasted, deep-fried, and batter-fried. The roots are also dried and ground into powder for use in soups and as a flavoring (Buishand et al. 1986). Turnip-rooted parsley leaves are used, like parsley (P. crispum var. crispum), for flavoring and garnishing soups, salads, and vegetable dishes. Example recipes

Mashed potatoes and parsley root (Schneider 1986) Soup of winter vegetables and dried mushrooms (Schneider 1986) Turnip-rooted parsley au gratin (Buishand et al. 1986)

Importance Turnip-rooted parsley is commercially produced in Germany and some eastern European countries (Buishand et al. 1986). It is grown to a limited extent in the United States. No statistics seem available on the amount or value of turnip-rooted parsley production in the world. In Canada it is a minor vegetable, apparently grown only in home gardens.


Turnip-rooted parsley should not be grown on recently manured soil as a substrate too rich in nitrogen will result in forked roots and excessive top growth. The most suitable soils are deeply cultivated loams (Halpin 1978).

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Climate

Turnip-rooted parsley is a cool-season plant that grows best at temperatures of 7–16°C, with growth slowing considerably below 7°C. Optimal germination occurs at 12–15°C. In Canada, plants are advisedly started indoors because a long growing season is needed to produce quality edible roots. If the roots are left in the ground until the second season, the plants bolt. Adequate moisture is important during germination and early growth, although less so as the plant matures (Halpin 1978; Yamaguchi 1983). Full sun should be provided.


Propagation is by seeds. Germination is slow and variable. Soaking seeds overnight and irrigating the soil before planting will increase germination efficiency. For outdoor planting, mixing in a few radish seeds (which germinate quickly) will help mark the rows where turnip-rooted parsley is positioned (Halpin 1978).

Harvest and storage

Turnip-rooted parsley is harvested when the roots reach a length of 12–18 cm. Roots of this size are more tender and sweeter than larger, thicker ones. A light frost helps to increase the sugar content of the roots. The roots can be left in the soil into winter if they are covered with enough mulch to prevent the soil from freezing. Otherwise, the roots are dug up and either eaten fresh or stored in damp sand in a root cellar. The roots will store for several months at 0–1°C (Halpin 1978; Buishand et al. 1986). Turnip-rooted parsley can produce as much as 28 t/ha fresh roots. The leaves can also be harvested throughout the growing season.

Example cultivars

Early Sugar, Hamburg Thick Rooted. Some Canadian garden catalogs offer turnip-rooted parsley in the herbs section, rather than with the vegetables. Intergeneric hybridization of parsley and celery (Apium graveolens) has yielded a range of potential crops (Simmonds 1976). Facciola (1990) provided a detailed description of turnip-rooted parsley cultivars available in the United States. Bettencourt and Konopka (1990) listed institutions in various countries that conserve germplasm of Petroselinum crispum.


The alternate name “Hamburg parsley” reflects the long association of turnip-rooted parsley with Germany.

Problems and potential Turnip-rooted parsley is a minor vegetable, mostly grown by Canadians whose ethnic background has resulted in familiarity with this vegetable. Commercial production is unlikely because several other, much more popular, established root crops are already widely available, namely carrots, parsnips, rutabagas, and turnips.


Phaseolus Leguminosae (Fabaceae) Pea family Légumineuses, famille du pois

Genus notes Phaseolus includes more than 20 species native to the Americas. In the past as many as 200 species were assigned to this genus (Bailey and Bailey 1976). However, many cultivated species once put in Phaseolus are now placed in the genus Vigna, which includes mostly Old World species (Debouck 1991). In Phaseolus there are five cultivated species, three of which, discussed below, are grown in Canada. The other two are P. acutifolius Gray, tepary bean, which originated from the semiarid parts of Central America and has been cultivated for 5000 years; and P. polyanthus Greenman, year-bean, which also originated in Central America and is cultivated in Guatemala and Mexico (Debouck 1991). The genus has been used for perhaps 8000 years in Middle America and the Andes. This long period of domestication has led to some striking changes between the wild and cultivated forms. Cultivars are differentiated by seed size, bush versus vine growth, and size of flower bracteoles. Some attributes may have derived from hybridization, for example, larger seed size of P. vulgaris after introgression with P. coccineus (Gepts and Debouck 1991).

Common bean

Names Scientific (Latin) name: Phaseolus vulgaris L. English common name: common bean Also: green bean, kidney bean, snap bean, pinto bean, haricot, Romano bean, French bean, frijol, string bean, salad bean, wax bean, runner bean (better reserved for P. lunatus) French common name: haricot commun (m) [Numerous variants exist as in English; e.g., wax bean = haricot jaune, snap bean = haricot mange-tout, white kidney bean = haricot blanc.]

Description and taxonomy Cultigens and wild varieties of the common bean were described by Gepts and Debouck (1991). The common bean is a herbaceous annual plant. It has been selected over the last 7000–8000 years from

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a wild-growing vine and has been turned into a major food crop grown worldwide. Selection of cultivated forms has resulted in a diversity of market types, which have been artificially classified by use as fresh pods (“snap” beans) or for the dried seeds. Beans may be either bush or vine (“pole”) types. Bush types of bean are sometimes included in var. humilis Alef. (Bailey and Bailey 1976). They are artificially classified on the basis of pod color (green, yellow, or bluish), pod texture (fleshy, slender, or wax-podded), and pod shape (flat, oval, or rounded cross section). Dry beans are the most important agricultural class of beans in the world, far more valuable than fresh beans (van Schoonhoven and Voysest 1991). The classification system used in Canada (Park 1989) includes the following categories: pea beans (navy or white beans, predominately grown in Ontario, used mainly for canning and soups) kidney beans (large kidney-shaped, red or white seeds, used in Mexican-style cooking and salads) black beans (similar in size to pea beans, grown in the prairies, mostly grown under contract for export) cranberry beans (medium to large, light pink to variegated red seeds, used mostly for Italian bean soup) pinto beans (semitrailing vines, medium-sized brownish seeds, used for baking and chili) red beans (medium-sized, dark red seeds, used in Mexican and Spanish cuisine) pink beans (mostly semiviny, with small pinkish seeds used for bean soup and chili) yellow eye beans (medium to large oval seeds with yellow pigment around the hilum [the scar where the seed joined the ovary], used for canning and baking) great northern beans (medium, slightly flattened, white beans, used in Italian cooking and baked bean dishes) Sixteenth-century Spanish texts mentioned the presence of the common bean in the Americas. The last emperor of the Aztecs, Montezuma, was estimated to have received annually 5000 tons (4535 t) of beans in addition to other crops such as corn. Common bean cultivation moved through the Americas and beans had diversified into various selections by the time the Europeans arrived. By then, beans had become a staple food even in parts of Canada. Columbus is thought to have brought seeds back to Europe, and, by the 17th century, their use was widespread in Eurasia (Nonnecke 1989; Gepts and Debouck 1991).

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The following two wild varieties of common bean occur: the large-seeded var. aborigineus (Burk.) Baudet, found in the Andes the small-seeded var. mexicanus Delgado, from Central America (Gepts and Debouck 1991) The two wild varieties can be hybridized, but with some difficulty.

Uses Common beans are used either as fresh pods or as dried seeds, which are cooked. Fresh beans are steamed, boiled, baked, or fried, and used in vegetable dishes, salads, stews, and soups. Dried beans are soaked in water and then boiled or fried for use in vegetable dishes, stews, casseroles, stir-fries, and chili. Both fresh and dried beans are canned and processed, and fresh beans are frozen (Tindall 1983; Nonnecke 1989). Example recipes

Bean soup with Pistou (Morash 1982) Bean-stuffed pasta shells primavera (Rozin 1992) Creole red beans and rice (Blanchard 1975) Green beans with sautéed walnuts (Levy 1987) Pink bean (pinto bean) whip (Hériteau 1978) Puréed snap bean soup (Morash 1982) Salmagundi (with fruit and chicken) (Morash 1982) Snap beans and tomatoes (Morash 1982) Stir-fried snap beans and beef (Morash 1982) Summer potato and green bean salad (Levy 1987) Wax (yellow) beans with French pesto sauce (Levy 1987) White bean salad (Ornish 1990)

Importance Fresh beans are particularly important in North America and in developed countries in Europe (Voysest and Dessert 1991). Major production areas are found from Mexico to South America, and in East Africa. However, dry beans are far more important economically and the common bean accounts for 95% of the annual production of 8.3 million tonnes of dry Phaseolus beans; the other 5% represents the other two species, scarlet runner bean (P. coccineus) and lima bean (P. lunatus) (Smartt 1989b). In Canada, dry field beans are grown mostly in Ontario; pea beans predominate, although most other types are also cultivated. Ontario grows about 40 000 ha of navy beans and 14 000 ha of colored beans

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including dark red kidney, cranberry, light red kidney, and black beans (Hill 1996). The short growing season in the Atlantic Provinces has limited the amount of dry beans produced commercially. In Quebec, commercial production is limited to the vicinity of Montreal, where mainly pea and cranberry beans are grown. Dry bean production has been increasing in the prairies, where pea and pinto beans predominate. In North America, about 85% of fresh beans are green, about 5% are wax (yellow), and about 10% are the pole type (Nonnecke 1989). Quebec is the major producer of fresh beans in Canada, followed by Ontario. Fresh beans are grown in home gardens across Canada (Park 1989).


Mechanized harvesting has radically altered bean production in North America, eliminating the traditional pole bean industry and introducing special soil requirements (Nonnecke 1989). The shallow-rooted bean plant is highly susceptible to nutrient deficiency. A uniform seedbed is essential, with good drainage and fertility. Common bean can grow in light sandy soils or clay loams. Soil pH should be near neutral (7.0). The seeds are adversely affected if planted directly with fertilizer. Therefore, placing fertilizer 5–7 cm to the side and 5 cm below the seeds is recommended.

Climate

Fresh pod production requires a relatively short maturation time (45–65 days) so that bush- or pole-type beans can be grown almost anywhere in Canada provided that mean 24-h temperature is 15–30°C. Commercial dry bean production requires longer warm periods and low atmospheric humidity to prevent foliar diseases and promote drying of the seeds. Flower abortion may occur if temperatures remain below 8°C for several days (Park 1989).


Beans are propagated by seeds sown once the soil becomes warm and frost danger is past. Insufficient soil moisture for maximum germination is often the most important limiting factor. Soil crusting is detrimental to seedling emergence. Bean plants do not lend themselves as well as peas and sweet corn to a temperature-based heat unit system for predicting success in a given area. In commercial operations, days to blooming and days to harvest are considered important. Precision seeders are used to sow the seeds (Nonnecke 1989). Inoculation with nitrogen-fixing Rhizobium bacteria is recommended where field beans have not been grown before. Growers should check the inoculation recommendations for their province (Park 1989).

Harvest and storage

Fresh and processed beans are usually harvested 14–18 days after the field is in full bloom. Newer mechanical harvesters can cut a swath of plants seeded together. Fresh beans are graded by sieving through a graduated series of screens, sorting to standard sizes. High respiration rates of pods necessitate rapid cooling, most easily achieved using

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water refrigeration. Beans cannot tolerate 0°C, which is the maintenance temperature for many vegetables. Instead, 3.3–5.5°C and high humidity are essential. A deviation of 1–1.5°C up or down greatly diminishes storage longevity. Beans may be stored for up to 11 days (Nonnecke 1989). Dry beans are sensitive to rough treatment. Special bean seed harvesters have been designed, with variable cylinder speeds to reduce damage. Beans should be harvested in the morning, while the pods are damp, to reduce damage (Park 1989). Dry beans held at low humidity can be stored for 3–4 years. Example cultivars

Bush beans include the following: green-podded: Contender, Derby Bush, Improved Tendergreen Bush yellow-podded: Dorabel Bush, Golden Rocky Bush, Roc Dor Bush novelty colors: Coco Rubico Bush, Marbel Bush, Royal Burgundy Bush. Pole beans include the following: green-podded: Blue Lake, Emerite, Kentucky Wonder Green yellow-podded: Kentucky Wonder Wax Types of field (dry) beans and the main cultivars grown commercially in Canada are discussed in Park (1989). Recent reports on trials of field bean cultivars are described for New Brunswick (LeBlanc and Thébeau 1988b), and for fresh beans in Montreal (Malo and Bourque 1992). Facciola (1990) provided an extensive description of bean classes and cultivars available in the United States. Additional collections of representative germplasm should be undertaken. The world repository for common bean germplasm is the Centro Internacional de Agricultura Tropical (CIAT) in Cali, Columbia. Breeding of the common bean was described in detail by Silbernagel (1986). Genetic resources of bean were discussed fully in Gepts (1988). Native Indians of Canada have preserved a wide array of land races of beans. (Land races are geographically distinctive forms of domesticated plants that have not been subjected to modern plant breeding.) John Baker of the Indian Agricultural Program of Ontario showed the authors of this book a remarkable collection of dozens of differently colored, differently shaped types of beans that have been preserved and perpetuated by Canadian tribal groups and families.

Additional notes Common beans are an important source of protein in the human diet, being rich in some essential amino acids such as lysine, threonine, valine, isoleucine, and leucine, but their nutritive value is limited because of low amounts of methionine and cystine.

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Curiosities


The names army beans and navy beans were coined because of the widespread use of common beans by the military to feed, at minimum expense, large numbers of people nutritious food that keeps well. In Italy beans are distributed among the poor on the anniversary of a death (Grieve 1978). The Jewish high rabbi is forbidden to eat beans on the Day of Atonement (Grieve 1978). A recently introduced product, “Beano,” contains an extract from Aspergillus, a fungus, that neutralizes certain sugars that otherwise cause the infamous flatulence associated with eating beans (Schwartz 1992).

Problems and potential Common bean is affected by a variety of pests and disease pathogens. Provincial recommendations should be followed (Park 1989; Hall 1991). One of the biggest problems in growing common beans is disease caused by a rust fungus. It has been estimated to cause 250 million dollars damage in the United States during a bad year. Tests are under way in North America to breed rust-resistant bean plants (De Quattro 1992). Other breeding objectives include resistance to common pests and other diseases, improved capacity for nitrogen fixation, especially in dwarf early maturing types, and increased tolerance to environmental stress. Certain antinutritional factors in common beans, including trypsin inhibitors, hemagglutinins, and flatus factors, are also the subjects of ongoing breeding research in attempts to reduce their significance. Domestic Canadian production almost satisfies the market for fresh beans for processing. By contrast, only about one-third of fresh beans destined for fresh markets are grown in Canada, mainly because of the extended growing season for fresh beans available south of the border and the limited storage time (1½ weeks) for beans.

Selected references Gepts 1988; Smartt 1989b; Gepts and Debouck 1991; Hall 1991; van Schoonhoven and Voysest 1991.

Lima bean

Names Scientific (Latin) name: Phaseolus lunatus L. Frequent scientific synonym: P. limensis Macf. English common name: lima bean

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Also: sieva bean, butter bean, civet bean, sewee bean, Carolina bean [European explorers first encountered lima beans in Lima, Peru— hence the name (Nonnecke 1989). Nevertheless, by convention the L in lima bean is not capitalized unless it begins a sentence.] French common name: haricot de lima (m) Also: haricot de Siéva

Description and taxonomy Baudoin (1988) described the cultivated and wild varieties, all of which are herbaceous annuals found in the Americas. Cultivated lima bean, var. lunatus, has both annual bush types and indeterminate vine types, both of which may become perennial in the native neotropical growing regions of Central and South America. Cultivated forms have been artificially classified on the basis of seed size and shape into three categories: lima type with large flat seeds sieva type with smaller kidney-shaped seeds potato type with small globose seeds Some seeds of the lima type have been found in Peru in sites dated at more than 7000 years ago (Debouck et al. 1987). The wild form of the species, var. sylvestris Baudet, occurs in Central and South America.

Pole lima bean

Uses Lima bean seeds (green or dried) are steamed, boiled, and baked. They are served as a side dish and are added to stews, casseroles, and soups (Nonnecke 1989). Young leaves are also sometimes eaten, but lima bean pods are not consumed. Lima beans are often cooked with sweet corn to form “succotash,” a mixture concocted originally by the Amerindians. Outside North America, lima bean plants have been used as a ground cover, as green manure, and for fodder. Sometimes lima beans are used to produce “bean sprouts” for consumption. Example recipes

Baby lima bean salad (Ornish 1990) Curried lima bean chowder (Rozin 1992) Limas with bacon dressing (Blanchard 1975)

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Succotash (Morash 1982) Thick lima bean soup with yogurt (Tudge 1980) Veal ragout (with lima bean sprouts) (Blanchard 1975)

Importance Ontario is the major producer of lima beans in Canada, and the total planted area is expanding. Typically, Ontario produces of the order of 1000 t annually (Anonymous 1991a). The most common Canadian limas grown are small and green-seeded; they represent cultivars best adapted to Canada because of their short growing season. These beans are primarily used in processed food and soups (Nonnecke 1989). The United States is the world’s largest producer, often producing over 50 000 t (Baudoin 1989).


Lima beans require soil similar to that for common beans, namely, warm, sandy loams with a pH of 6.0–7.0 (Nonnecke 1989).

Climate

Lima bean is a tropical plant, requiring warm, frost-free weather. It should be grown in the hottest part of the growing season. It may emerge in as little as 1 week if soil temperature is 25–30°C. Emergence may take several weeks if the soil temperature is below 20°C (Nonnecke 1989). Some cultivars recently introduced into Canada require only 60 days to mature.


Lima beans are propagated by seeds sown after the soil becomes warm. Germination is retarded if fine hairline cracks develop when the seed is harvested. The seeds are therefore handled with extreme care to prevent damage. Precision seeding is used to maximize commercial yields (Nonnecke 1989).

Harvest and storage

Mechanized commercial harvest requires attention to details, such as measuring moisture content of shelled beans to determine harvest readiness. Lima beans are combined after swathing, preferably in the early morning before dew evaporates, to protect the seeds from excessive damage that results when they are dry. The seeds must be cooled quickly to prevent deterioration from their high respiration rate. Limas in the pod will store for less than 1 week. The beans are hand picked for fresh marketing, resulting in high labor cost (Nonnecke 1989).

Example cultivars

Bush lima type: Eastland, Fordhook Bush 242, Limelight (developed by Agriculture and Agri-Food Canada Research Station, Lethbridge, AB, this cultivar can mature in 60 days). Pole lima type: King of the Garden. Most modern breeding of lima bean has been done in the United States. Interest in mechanical harvesting and industrial processing has resulted in the selection of short-season varieties, determinate growth,

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and synchronous fruit maturation. Facciola (1990) provided an extensive description of lima bean cultivars available in the United States. The Centro Internacional de Agricultura Tropical (CIAT) in Cali, Columbia, is the world repository for lima bean germplasm. Additional germplasm resides in the United States at the National Seed Storage Laboratory, Fort Collins, Colo., and with the U.S. Department of Agriculture in Beltsville, Md. Further collecting of germplasm in the tropical centres of diversity is most desirable (Baudoin 1988).

Bush lima bean


Lima beans were not only an important food source but were also incorporated into the art and symbolism of the pre-Columbian culture of Peru (Baudoin 1988). Mature lima beans contain the cyanogenic glycoside phaseolunatin, and an enzyme that releases hydrocyanic acid from the glycoside. These chemicals are most prevalent in the seeds, and colored beans produce more of the cyanogenic glucoside than white beans. Cooking generally destroys this poison, and in any case poisoning is unlikely in humans because of the small quantities ingested. However, there have been occurrences of livestock poisoning when animals have gained access to fields of lima beans and have eaten considerable quantities (Fuller and McClintock 1986).

Problems and potential Lima beans are susceptible to the same weed, insect, and disease problems as common beans. However, limas are less affected by rust disease. Lima bean is a minor crop in Canada with seemingly little potential for increased production. Development of a greater variety of shorter-season cultivars than presently available for the short Canadian growing season might stimulate increased interest in production in Canada.

Selected references Debouck et al. 1987; Baudoin 1988; Baudoin 1989.

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Scarlet runner bean

Names Scientific (Latin) name: Phaseolus coccineus L. English common name: scarlet runner bean Also: Dutch case-knife bean French common name: haricot à rames (m)

Description and taxonomy Two cultivated subspecies of P. coccineus have been recognized, as noted below (Delgado Salinas 1988). These plants are perennial herbaceous vines, usually grown as annuals. They are employed mostly as ornamentals, but also for their edible pods and dried seeds. The two are subsp. coccineus, domesticated as early as 9000 years ago and grown in parts of Mexico, Guatemala, and other regions of Central America as well as Africa, Europe, and North America (some bushy varieties of this vine have been produced) subsp. darwinianus Hdez. and Miranda, grown in parts of Mexico, Guatemala, and other parts of Central America. Three wild subspecies have also been recognized (Delgado Salinas 1988) as follows: subsp. formosus (Kunth) Mare., Masch. and Stain, a polymorphic taxon occurring at elevations between 1000 and 3000 m from Mexico to Panama subsp. glabellus (Piper) A. Delgado, found in Mexico from 750 to 1600 m. (Schmit et al. [1991] argued that it should be recognized as a separate species) subsp. grieus (Piper) A. Delgado, growing in Mexico from 610 to 2250 m

Uses Young pods 12–15 cm long are picked fresh and are steamed, baked, or fried. They can be consumed in vegetable dishes, stir-fries, soups, and stews. Mature pods become tough and stringy, but the mature seeds can be dried and used like other dried beans. In its native

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habitat the plant is seasonally dormant, surviving by means of an enlarged fleshy tap root. In some Central American countries the dormant root is boiled and eaten (Delago Salinas 1988). Scarlet runner bean is often planted as an ornamental vine, for its attractive red flowers. Example recipe

Stir-fry runner beans (Buishand et al. 1986)

Importance Scarlet runner bean is of minor importance in Canada and is not grown commercially. The white-flowered variety is cultivated for food overseas (Smartt 1989a). It is called Dutch case-knife bean in Europe and, in South Africa, large white kidney bean (a name best avoided as it could be confused with common kidney bean, P. vulgaris) (Liebenberg 1989).


Scarlet runner bean does well in rich, light, well-cultivated soil. Soils high in nitrogen should be avoided (Halpin 1978).

Climate

Seed should be sown when the soil temperature has reached about 15°C. Watering during dry periods is often required (Delgado Salinas 1988).


Because the scarlet runner bean is killed by frost in Canada, the tuberous rootstock can be dug up in the autumn and overwintered for planting in the following spring. Normally, however, scarlet runner bean is propagated by seed and is grown as an annual in Canada, although it is cropped as a perennial in some parts of Central America. The seeds are sown once the soil warms. Scarlet runner bean is a vine that must be grown on a trellis or fence so that the pods can hang unimpeded. Vines will grow 2–3 m (Delgado Salinas 1988).

Harvest and storage

The pods should be harvested when young and tender, as regular harvesting promotes continued production. A yield of 3125 kg/ha has been recorded for scarlet runner bean in Mexico, from a planting of 6770 plants per hectare (Delgado Salinas 1988). Scarlet runner beans will store for a week at temperature of 3–5°C.

Example cultivars

Scarlet runner. Facciola (1990) provided an extensive description of cultivars available in the United States.


Beans are one of the triumverate of important crops—maize, beans, and squash—used by New World Indians for millenia to achieve a balanced diet. Vinelike climbing forms were commonly planted among maize plants so that the beans could use the corn

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stalks as supports upon which to climb. Scarlet runner and lima beans are grown on corn in this fashion today in Central America. The scarlet runner bean climbs by winding around supporting objects from right to left (i.e., circling anticlockwise, viewed so that the twining stem is growing towards the observer). Many other kinds of vines, hop (Humulus lupulus L.) for example, climb with an opposite motion.

Problems and potential In Canada, scarlet runner bean is used only in home gardens, both as an attractive ornamental vine and for its edible pods. Usage is likely to remain limited in Canada. Delgado Salinas (1988) reported that scarlet runner bean could gain wider acceptance if shorter, bush-type cultivars were developed that would allow large-scale mechanization. Production of self-fertile plants would stabilize and increase yield. The potential as a green manure should be examined as the roots are heavily nodulated with nitrogen-fixing bacteria.

Selected references Delgado Salinas 1988; Smartt 1989a.

Pisum Pea Leguminosae (Fabaceae) Pea family Légumineuses, famille du pois

Genus notes The genus Pisum contains two species of usually vinelike herbs native to the Old World (Waines 1975). One species, P. sativum L., is cultivated throughout the world.

Names Scientific (Latin) name: Pisum sativum L. English common name: pea Also: garden pea, English pea, common pea, green pea, field pea, snow pea [for edible-podded varieties only] French common name: pois (m) [Variants have names such as green pea = petit pois, snow pea = pois mange-tout.] One of the English meanings of the word pea is “any of various leguminous plants relating to or resembling the pea—usually used with a qualifying term”; thus chick-pea = Cicer arietinum L. and black-eyed pea (cowpea) = Vigna unguiculata (L.) Wal. subsp. unguiculata. In the southern United States, the term “pea” usually refers to the black-eyed pea.

Edible-podded pea

Description and taxonomy Pisum sativum includes cultivated and wild forms. Breeding studies have shown that it is a variable species including many forms that were once regarded as separate species (Ben-Ze’ev and Zohary 1973; Adsule et al. 1989). Three basic classes of cultivated peas have been recognized. While these are sometimes afforded taxonomic designation, the classes are apparently artificial. They are as follows: Green pea: This is referred to as var. sativum by some authors (Bailey and Bailey 1976). The pods are tough, with fibrous lining,

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but the seeds are very sweet. The flowers are usually white and the seeds are used as human food. Edible-podded pea: This is referred to as var. macrocarpon Ser. by some authors, and as sugar pea and snow pea (Bailey and Bailey 1976). The pods are thick, soft, and lack a fibrous lining. The flowers are usually pinkish or purple and young pods are eaten as human food. Oriental names are common for this kind of variant, reflecting its common use by eastern peoples. For example, “shih chia wan tou” and “ta li wan tou” (Mandarin), “sic kap woon dou” (Cantonese), “no luan tau” (Hong Kong), and “saya-endo” (Japanese). Field pea: This is referred to as var. arvense (L.) Poir. by some authors (Bailey and Bailey 1976). The flowers are usually pink and purple. The seeds are used for human food and Bush pea animal meal and the plants for fodder and silage. Wild forms include subsp. syriacum Berg. (P. humilis Boiss. and Noë) subsp. elatius (Bieb.) Ascherson & Graebner (Tutin et al. 1968; Adsule et al. 1989) Subspecies syriacum probably served as the primary stock that led to domestication, and subsp. elatius also contributed to the variation of cultivated pea. The wild forms are occasional weeds of southern Europe and western Asia (Waines 1975). Peas were domesticated very early. They were used in neolithic farming villages in the Near East, at least as early as 7000–6000 B.C. (Gritton 1986). Remains from a Stone Age village in Switzerland revealed pea seeds from about 3000 B.C. (Biddle et al. 1988). Pea pods were not used in cooking until the Middle Ages. With colonization of North America the pea became widely distributed in the New World (Nonnecke 1989). Many peas grown in Canada are determinate. Such plants are bushlike in growth with a terminal inflorescence that produces a limited number of fruits. Vine pea Indeterminate pea plants are more vinelike, lack a terminal inflorescence, require poles or trellises for support, and continue to produce fruits for a prolonged period. Pods formed on determinate plants are usually completely full of peas, whereas the indeterminate plants rarely have filled pods (Nonnecke 1989).

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Uses Green peas and edible-podded peas are used as human food. Green peas are grown commercially primarily for canning (for which demand is declining) or freezing. The pea ranks as one of the major cooking vegetables in the temperate world, along with potatoes, sweet corn, and beans (Nonnecke 1989). “Petits pois” is a culinary term for immature garden peas. “Split peas” are peas with the skin removed. Edible-podded peas are eaten while they are still immature, before much starch has accumulated in the seeds; they can be consumed raw, or steamed, cooked whole, or fried. They are used increasingly in cooking and are particularly popular in oriental cuisine. Field peas are employed as human food and animal feed. They are used in Canada as dry split peas and in the manufacture of soup. In other parts of the world dried peas are soaked in water and then used in various cereals, unleavened breads, or rice dishes. They are also used as “snaps” after frying in oil with turmeric and onions. Additionally, peas are a valuable one-harvest forage crop used as silage or green chop for animals (Langille 1980). Extracts, including protein, starch, and fibre, have been obtained from peas for use in food and industrial products. In Manitoba various products have been produced from flour obtained from pea seeds, and the high-fibre flour has been in great demand for use in high-fibre bread and pasta (Adsule et al. 1989; Ali-Khan and Zimmer 1989). Example recipes

Creamed sugar peas (Organ 1960) Crêpes with peas, onions, and peppers in curry sauce (Levy 1987) Fresh pea soup (Morash 1982) Fresh pea soup with mint cream (Levy 1987) Maltese scampi (Morash 1982) Pasta with peas (Morash 1982) Sautéed sugar snap (or snow) peas, ham, cucumbers, and dill (Schneider 1986) Snow pea stir-fry (Richardson 1990) Spicy peas and rice (Morash 1982) Sugar peas with lemon butter (Buishand et al. 1986) Sugar snap pea and shrimp appetizer (Morash 1982)

Importance Peas are an important world crop, with annual yields worldwide often about 5 000 000 t (Nonnecke 1989). Annual yields in Canada are of the order of 70 000 t (Dubé et al. 1990). Canada grows almost all of the green peas used in the fresh and processing industry. Ontario is the largest producer, followed by Quebec and British Columbia. Production of field peas has increased dramatically in western Canada during the 1980s, especially in Saskatchewan. More than 90% of field peas grown in Canada are yellow-seeded. Canada exports over 80% of field pea production to about 20 countries in Europe, South America, and Asia (Ali-Khan and Zimmer 1989).

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Well-drained clay loam soils are best suited for peas. Light, sandy soils with a low moisture-holding capacity generally produce lower yields. Heavy clay soils may be too cool and wet, especially if poorly drained. To reduce disease problems, crop rotation is recommended for commercial producers. Peas and other legumes, such as lentils, field beans, and faba beans, should not be grown in the same soil for at least 4 years. Other crops susceptible to the fungal disease sclerotinia white mould, including sunflower, canola, mustard, and safflower, should be avoided in the same rotation (Nonnecke 1975; Ali-Khan and Zimmer 1989). Peas respond to inoculation with recommended nodule-forming bacteria of the genus Rhizobium. These bacteria produce nitrogen-rich nodules on pea roots. Peas grown in previously uncultivated soil or in soil not previously used for pea production are more robust and produce heavier crops when the bacteria are added (Ali-Khan and Zimmer 1989).

Climate

Pea is a cool-season plant well adapted to the Canadian climate. Germination is significantly reduced at temperatures below 4–5°C or above 30°C. The optimum soil and air temperature for pea growth and crop production is 24°C. However, air temperatures above 24°C cause pea to grow too rapidly, developing a poor root system and a poor crop. In practice, peas should be sown as early as soil and moisture conditions permit. Frost may damage young apical shoots, which enhances the development of secondary shoots and results in a higher pod count (Ali-Khan and Zimmer 1989; Nonnecke 1989).

Propagation and Cultivation

Peas are propagated by seeds, and pedigree seed is recommended for commercial growers. Commercially grown pea seeds are usually treated with a fungicide to reduce disease problems during germination. Peas can be grown on zero- or minimum-tilled land, although special equipment is needed. Studies by Agriculture and Agri-Food Canada at the Indian Head Experimental Farm, Sask., have indicated no difference in yield of peas grown under conventional, minimum, or zero tillage. Peas do not compete well with weeds so that a thorough weed-control program is recommended (Ali-Khan and Zimmer 1989).

Harvest and storage

Green peas and edible-podded peas were traditionally hand-harvested, which was very labor intensive. Modern commercial pea harvests are so streamlined that often peas reach processors within 30 min. Pea viner machines are either self-propelled or pulled by tractors. The machines cut the vines, remove the pods and shell the peas. Peas destined for the fresh market are shipped in the pods. Usually the darker-colored peas are considered the sweetest and most desirable for fresh or frozen use. Edible-podded peas are also picked and shipped as whole pods. The seeds seldom develop fully, but the shell becomes fleshy and juicy. Fresh green peas must be washed and hydrocooled immediately to 0°C and 95% relative humidity. Peas can be stored for 3 weeks under these conditions (Ellis et al. 1988; Lee 1989; Nonnecke 1989).

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Field peas are also mechanically harvested. The peas should have a moisture level of 16–18%, although to maintain the seed color of green-seeded cultivars they are harvested early at 18–20% and then dried with artificial heat to 16%. Peas are combined directly or after swathing. Direct combining is preferred because this reduces seed loss, but swathing may be necessary if there is living plant material (including weeds and secondary growth of pea plants) left in the field. To encourage drying of the top growth, a desiccant can be used to kill the secondary growth of pea vine. The desiccant should not be applied too early or the pea seeds will wrinkle, rendering them unmarketable. Pea vines are so light when dry that they should not be left in the field for long before combining as they can be easily tangled by wind. Canadian seed grade standards require field peas to be below 16% moisture. Peas are cleaned to remove any green (immature) pea seeds or weed seeds. If dryers are used, peas can be subjected to temperatures up to 71°C, unless they are destined for use as seeds the following year, in which case the temperature must stay below 45°C. Peas are stored in dry bins and are loaded and unloaded with augurs, operating at a low speed to reduce seed shattering (Ali-Khan and Zimmer 1989). Example cultivars

Green pea: bush peas: Freezer 69, Improved Laxton’s Progress, Kelvil, Little Marvel, Olympia vine peas: Green Arrow, Homesteader, Petit Pois, Tall Telephone Edible-podded pea: bush peas: Dwarf Gray Sugar, Little Sweetie, Sugar Ann vine peas: Oregon Sugar Pod, Melting Sugar, Sugar Daddy, Super Sugar Pod, Sweet Snap

Field pea: yellow-seeded: Century, Bellevue, Express, Lenca, Tara, Tipu green-seeded: Finale, Princess, Triumph In Canada, more than 90% of field peas grown are yellow-seeded and the remainder are green-seeded. The cultivar Century is grown on 45% of the land planted to peas (Ali-Khan and Zimmer 1989). Pea breeding was discussed in detail by Gritton (1986). Facciola (1990) provided an extensive description of pea classes and cultivars available in the United States.


Peas are renowned as the subject of studies by the Austrian monk Gregor Mendel (1822–1884). His epochal experiments ushered in the science of genetics. Mendel’s studies of heredity in the common garden pea were conducted from 1856 to 1865, in a

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monastery garden at Brünn (Brno), then in Austria (now the Czech Republic). By examining such contrasting characters as tall versus dwarf size, wrinkled versus smooth seeds, and colors of peas, Mendel recognized that certain characteristics were inherited as units, and that in combination some of these genetic units were expressed (i.e., were dominant) at the expense of others. The pea has become one of the most studied organisms in genetics. It has been pointed out that there is a parallelism between the groups of early domesticates of the Near East (pulses, including peas, and grains) and those of Mesoamerica (corn and bean). In both centres of origin, agriculture was based on producing a combination of grass seeds (rich in starch) and legume seeds (rich in proteins), such that the deficiences of each type are compensated by the other to produce a balanced diet. Although perhaps not a conscious selection on the part of people, it is interesting that the plants chosen for domestication resulted in a balanced diet.

Problems and potential Pea plants suffer from a variety of diseases and insect pests that can reduce productivity significantly (Martens et al. 1984; Ali-Khan and Zimmer 1989). As noted above, peas should be planted in a rotation of at least 4 years. The pea aphid is the most important insect pest of field peas. The population of pea aphid increases in the hot, dry days of July and August and can render harvest of some fields uneconomic (Timlick and Turnock 1991). Breeders have developed many cultivars resistant to certain diseases. However, root rot is still a problem. Some peas are resistant but have a poor taste (Polk 1991). Peas are an important part of the Canadian vegetable industry with most of the demand for fresh and processing peas satisfied domestically. Most field peas are exported. There is probably little potential for significant expansion of the pea crop, unless new markets are found.

Selected references Nonnecke 1975; Anonymous 1986b; Biddle et al. 1988; Ali-Khan and Zimmer 1989.

Portulaca Purslane Portulacaceae Purslane family Portulacacées, famille du pourpier

Genus notes The genus Portulaca contains more than 100 species of fleshy or trailing, mostly annual herbaceous plants (Bailey and Bailey 1976). A few species are grown as annuals in flower gardens and one of these, also used as a potherb, is discussed below.

Names Scientific (Latin) name: Portulaca oleracea L. Common English name: purslane Also: summer purslane, pusley, pursley Common French name: pourpier (m) Also: pourpier potager

Description and taxonomy Green purslane Portulaca oleracea is an annual, fleshy, herbaceous plant that is found in many parts of the world (Clapham et al. 1987). Although it is not certain that truly wild forms exist today, a wild and a cultivated subspecies have been recognized (Schultze-Motel 1986) as follows: subsp. oleracea, a widespread weed of southern and central Europe, apparently (see below) spread to North America. It is a procumbent or decumbent weed of cultivated areas and can be troublesome in crops, particularly vegetables. subsp. sativa (Haw.) elak. is a more robust, erect plant in all its parts than subsp. oleracea. It is cultivated as a vegetable in southern Europe and parts of Asia and North America. The native range of P. oleracea is uncertain, although it may be the region west of the Himalayas to southern Russia and Greece. It was transported to America from Europe, although some believe that it is also indigenous to America, where archaeological remains have been found. It has been used since ancient times by the Romans and others around the Mediterranean as a potherb (Foster 1980; Yamaguchi

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1983). Purslane is a common, introduced weed of cultivated and waste ground in North America and has been found as a weed in all Canadian provinces except possibly Newfoundland (Scoggan 1978–1979).

Uses Purslane can be eaten raw in salads, where it imparts a piquant lemony flavor. It can be boiled or stir-fried and is added to soups and other vegetable dishes. The leaves can be preserved by freezing or drying. Purslane is occasionally served in fine European-style restaurants (Foster 1980; Gorman 1988). It has a mild, nutty flavor and a crunchy texture much like bean sprouts. Example recipes

Chicken fricassee with purslane (Szczawinski and Turner 1978) Fried eggs with purslane (Szczawinski and Turner 1978) Purslane and pear salad (Richardson 1990) Purslane casserole, Manitoba style (Szczawinski and Turner 1978) Purslane supreme (Szczawinski and Turner 1978)

Importance No statistics are available on production or use of purslane. It is cultivated in Egypt and Sudan and is grown locally in parts of the Mediterranean, France, and England (Yamaguchi 1983). In Canada it is grown only as a curiosity in home gardens.


Purslane in its weedy form will grow on most soil types. Loamy soils with high organic matter are beneficial. Wild purslane is known to tolerate salty soils.

Climate

The weedy form of purslane is well adapted to the climate in southern Canada. Although the wild plant thrives in arid areas, supplementary water for the cultigen is beneficial during dry periods.

Large-leaved golden purslane


Propagation is by seeds. The seeds are spread on the soil in a sunny location after the last frost and pressed into the ground. They should be kept watered with a fine mist until germination (Bennett 1982).

Harvest and storage

The plant is harvested when it is 10–15 cm tall. The leaves should be used fresh. It is important to note that if purslane is allowed to go to

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seed it may spread as a weed in later years. It is prudent to remove any flowers as they form (Bennett 1982). Example cultivar

Large-leaved Golden. The cultivated form is occasionally sold in Canadian garden catalogs as “summer purslane” or “purslane.”

Additional notes Purslane has the highest content of alpha linolenic acid (a type of omega-3 fatty acid) of any leafy vegetable studied (300–400 mg per 100 g). Compared with spinach, it has 10 times the amount of this chemical. The human body may convert it to other fatty acids, such as those found in fish oils, that lower blood cholesterol and blood pressure. Purslane also contains high levels of vitamin E (12.2 mg per 100 g), an antioxidant that protects cell membranes from breaking down (Gorman 1988; Adams 1992). Curiosities

Seeds of wild purslane have been found to survive for 40 years (Adams 1992). The American writer Henry David Thoreau (1817–1862), renowned for his “back-to-nature” philosophy, wrote at his retreat at Walden Pond “I have made a satisfactory dinner … simply off a dish of purslane … which I gathered in my cornfield, boiled and salted” (Richardson 1990).

Problems and potential Because it tolerates both dry conditions and salty soils (which are often produced where land is irrigated), purslane has been thought to have some potential as an alternative crop of the southwestern United States (Adams 1992). It is conceivable that it might have similar potential for areas of Canada marginally suitable for agriculture. Nevertheless, at present, purslane seems likely to remain a novelty of home gardens. Because of weedy potential it should be kept under control.

Selected references Foster 1980; Bennett 1982; Gorman 1988; Adams 1992.

Raphanus Radish Cruciferae (Brassicaceae) Mustard family Crucifères, famille de la moutarde

Genus notes The genus Raphanus consists of about 10 annual or perennial herbaceous species, native from Europe to eastern Asia (Bailey and Bailey 1976). One species, cultivated for human food and animal feed, is discussed below.

Names Scientific (Latin) name: Raphanus sativus L. English common name: radish French common name: radis (m) (Variants such as black radish = radis noir)

Description and taxonomy Raphanus sativus is a short-lived, annual (or occasionally biennial) plant. Radish cultivars have been selected for their leaves and for their edible storage organs, generally referred to as “roots.” Like many other so-called “root crops” (e.g., carrot and rutabaga), the upper part of the storage organ is derived from the hypocotyl, an embryonic Short-leaved early scarlet intermediate radish tissue that is neither true root nor shoot but is located between these. The lower part of the root is derived from the true root. Although it is not completely correct to use the term roots for the storage organs of radishes (because the tops are not root tissue), we follow the common practice of referring to radishes as roots. Several classes of radish have been selected through domestication, as noted below.

small radish: This form is referred to as var. sativus (Pistrick and Jarvis 1987) or var. radicula Pers. (Schultze-Motel 1986). The “small radish” is the common spring radish familiar in North America and is grown in many parts of the world for its edible roots; these radishes can be cylindrical, round, or olive-shaped and red, white, or red with a white tip.

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“Forcing radishes” are types grown out of season, often in an indoor environment, cold frames, or hot beds; these early kinds reach an edible size quickly, often in 20–30 days. – “Summer radishes” have roots that mature moderately quickly, requiring 6–8 weeks to reach marketable size (1–2 cm in diameter); however, their flesh makes them unsuitable for long-term storage, and unless harvested at an early stage, hollow spaces develop in the central part of the storage organ. – “Winter radishes” are firm-fleshed types that require several months to reach maturity, often attain large size, and may be stored under appropriate conditions for winter use (some forms of the following classes are also considered to be winter radishes). Black or large radish: This kind is referred to as var. niger (Mill.) Kerner (Schultze-Motel 1986) or var. longpinnatus Bailey (Tindall 1983). It includes annual to biennial cultivars. This class is the oldest and was known in ancient Egypt. It is grown extensively in eastern and central Asia for its roots, leaves, and young seed pods, including the long white-rooted radish, weighing up to 1 kg, called “daikon” in Japan. Several cultivars grown for the edible roots are available in Europe and North America. Mougri-radish: This is referred to as var. mougri Helm or R. caudatus L. by some authors (Schultze-Motel 1986). It does not produce fleshy roots and is cultivated in southeast Asia and India for its edible leaves and young seed pods. The roots may become 20–100 cm long; hence the common name “rat-tailed radish” (also known as “aerial” and “serpent” radish). In China, this form is called “lobok,” and the seed pods are used fresh or pickled. Fodder-radish: This class is referred to as var. oleifera Stokes by some authors (Schultze-Motel 1986) and is also called “oil radish.” It has a root that is either not fleshy or only sparsely fleshy. It is grown for its foliage and is used as animal fodder or green manure in Europe and increasingly in North America including Canada (Kunelius and Sanderson 1990). Raphanus sativus is not known in the wild (except for occasional escapes and ruderal forms) and its ancestry is uncertain. Postulated wild ancestors are discussed by Simmonds (1976). The area of maximum diversity of cultivars is from the Mediterranean to the Caspian Sea, where a number of wild, possibly ancestral species of Raphanus occur. The radish has been cultivated for thousands of years and was grown extensively in ancient Egypt during the time of the Pharaohs (2700 B.C.). The radish was spread to China about 500 B.C. and to Japan around A.D. 700. The “small radish” class was selected much later than the “black radish” class. The radish was introduced to northern Europe Long black Spanish winter radish in the 16th century as a long white-rooted form. By the –

Olive-shaped scarlet radish

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18th century, red globular forms were developed. Radish was brought to North America in the early 19th century (Simmonds 1976; Nonnecke 1989).

Uses The small radish familiar to most Canadians is eaten raw. The large radishes of Asia, including those of China and Japan, are generally boiled and eaten as a vegetable, or pickled. Some large radishes are now available in Canadian garden catalogs. Radish seed sprouts are added for their spicy flavor to some brands of sprouts. Although used primarily as a salad vegetable in North America, radishes are used in several other ways elsewhere. Notably in Asia, oilseed radish is used for production of a drying oil, useful for making soap and for edible purposes. Radishes are grown as a livestock feed, particularly in western Europe. In some Eastern countries the leaves and seed pods of some cultivars are boiled and eaten as vegetables. Example recipes

Black radishes in cream sauce (Schneider 1986) Radish Chinese style (Morash 1982) Radish flower canapés (Levy 1987) Radish top soup (Morash 1982) Red-cooked beef and oriental radish (daikon) (Schneider 1986) Salad of radish sprouts, endive, pepper, mushrooms (Schneider 1986) Sautéed oriental radish (daikon) slices (Schneider 1986) Soup of pork, black radish, and noodles (Schneider 1986) Spinach and radish sprout salad (Richardson 1990) Spring radish, chicken, and scallion dinner (Morash 1982)

Importance The radish is a minor crop, but one which is extremely popular in gardens and markets. Radishes of the various classes are grown in temperate and tropical areas, worldwide. In Canada domestic production represents about a third of total radishes consumed (Coleman et al. 1991). About 6000 t are produced annually in Canada, mostly in Ontario, Quebec and British Columbia (Anonymous 1993a, 1993b).


Radish is not demanding as to soil type and grows well on a variety of soils. The seedbed should be friable and free of stones.

Climate

In Canada, radish cultivars are generally adapted to short seasons, reaching marketable size within 1 month after planting. Therefore radishes can be grown in most parts of Canada. The main challenge of radish production is avoiding hot, dry weather, which causes root

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elongation and the development of a stronger flavor. Radishes require uniform moisture to grow rapidly. Otherwise, the roots become tough and pithy. Radishes grown under long days (15 h or more of sunshine per day) develop misshapen roots and elongated tops that quickly produce flower stalks. In higher latitudes, cool muck soils counteract summer heat and long daylength. Rate of seedling emergence is controlled by temperature. At 5°C, radishes take 29 days to emerge; at 10°C, 11 days; at 15°C, 6 days; at 20–30°C, 4 days (Nonnecke 1989). The best quality and root shape are obtained when the crop grows in moderate temperatures (10–18°C), in intermediate to short day lengths (Anonymous 1988a). Propagation and cultivation

Radishes are propagated by seeds. For commercial crops it is important to use uniform seeds that are planted by precision seeders to a standard soil depth. With precision seeding, thinning is not required, and because of rapid growth, weeding is generally also not required. Deep planting (more than 2 cm) induces root elongation. The radish is grown in Canada primarily as White Strasburg radish a cool-season annual, reaching marketable size in 21–28 days, or longer in cool weather. It grows so rapidly that several crops of radish may be raised each season. The radish crop occupies the ground for only about 1 month, so it may be used as one in a series of “succession crops,” followed perhaps by bush beans, late beets, Chinese cabbages, late cabbages, late cauliflowers, late carrots, late lettuce, fall spinach, turnips, tomatoes, muskmelons, or indeed other crops of radish. Because they are early, quick-maturing, and compact, radishes are usefully interplanted with later, slowergrowing, wider-spaced crops such as Brussels sprouts, cabbages, tomatoes, and vine crops. Whether it is grown simultaneously or in sequence with other crops, the radish is an excellent “companion crop.” It is useful in still another way as a companion. Radish seeds germinate quickly, producing visible seedlings in 2–3 days under favorable conditions. Thus when sown in the same row as slower-germinating crops like beet, carrot, parsley, and parsnip, radishes serve to mark the location of the planting, facilitating early cultivation.

Harvest and storage

Small radishes can yield 10 000–15 000 kg/ha and the large radish class (including Chinese and Japanese radish cultivars) can produce 30 000–40 000 kg/ha (Anonymous 1988a). In Canada, good yields per metre average 20–25 roots. Experimental plantings of winter radishes in British Columbia have suggested that yields of up to 80 t/ha are possible there. Commercial growers harvest crops in the order of 100 000 roots per hectare. Radishes that are not harvested at maturity may produce flower stalks, and the crop loses quality. Radishes are mechanically harvested, topped, trimmed, and combined in one

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process. Topped radishes are loaded into bulk carriers in preparation for washing, grading, and packaging. They are then hydrocooled after grading and before packaging, usually in cello bags. Bunching of radishes is still carried out primarily by hand. Bunched radishes are also hydrocooled and packaged with ice slurry for shipping. Because the leaves on bunched radishes wilt, they should be kept near 2.5°C until shipping. Placing radishes in an atmosphere of 1% O2 increases storage success (Nonnecke 1989). Bunched summer radishes can be stored for 1–2 weeks at 0°C at a relative humidity of 90–95%; topped radishes can be held for 3–4 weeks. Winter radishes are not often grown in Canada as they require a longer season (45–100 days) than the summer types and are not as palatable. They can be stored for 2–4 months at 0°C and a relative humidity of 90–95%. Example cultivars

Small radish: early varieties: Champion, Jumbo, Novired, Scarlet Globe Special main season varieties: Big Ben, Cherry Belle, Comet, Easter Egg, French Breakfast, Plum Purple, Red Devil B, Saxa Black or large radish: All Season (this is the “daikon” radish of east Asia), Chinese Rose, Chinese White, Japanese Sakurijima, Long Black Spanish, Minowase. Chinese Rose is the most frequently encountered large radish in North America. In Canada’s Oriental communities, black radishes are often encounted as “daikon” (Japanese) and “lo bok” (Chinese). Sukarijma is reputedly the world’s largest radish cultivar. Some giant black radishes develop half their lengths of 30–100 cm out of the ground, and so are an attractive garden curiosity. One Canadian garden catalog lists “Daikon sprouting radish.” The vigorous Daikon radish could be expected to produce relatively large radish sprouts. Bettencourt and Konopka (1990) listed institutions in various countries conserving radish germplasm. Genetic diversity and conservation requirements for radish were described by Anonymous (1981). Facciola (1990) provided an extensive description of classes and cultivars available in the United States.

Additional notes The characteristic pungent flavor of radishes is caused by isothiocyanates. As with the mustards (Brassica and Sinapis), an enzyme causes the breakdown of a glucoside to produce a hot-tasting mustard oil. Peeling a radish deprives it of most of the enzyme responsible for the production of the mustard oil, and therefore removes much of the piquant taste. Curiosities

It has been reported that radishes were so highly valued in ancient Greece that, in offerings to the God Apollo, the Greeks presented small replicas of radishes formed of beaten gold, whereas beets were made of silver, and turnips of lead. Radishes weighing over 45 kg (100 pounds) have been grown.

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Problems and potential Radishes are a minor crop in Canada, with domestic production acounting for about a third of total consumption. Although radish is not likely to increase in popularity, domestic production for the local market could be expanded. Radishes grown in greenhouses supply some domestic product. This output could be increased to offset the need to import radishes during the winter months.


Scorzonera Scorzonera Compositae (Asteraceae) Sunflower family Composées, famille de la marguerite

Genus notes Scorzonera has about 150 species of perennial (rarely annual) herbaceous plants, native to Europe and central Asia (Bailey and Bailey 1976). One species, cultivated for its edible roots and leaves, is discussed here.

Names Scientific (Latin) name: Scorzonera hispanica L. English common name: scorzonera Also: black salsify, Spanish salsify, viper’s grass, black oyster plant French common name: scorsonère (f) Also: salsifis noir Scorzonera should not be confused with the Spanish oyster plant (Scolymus hispanicus L.), another essentially wild species of the sunflower family that is sometimes cultivated for its edible root. Neither species should be confused with the true oyster plant (Tragopogon porrifolius L., better known as salsify and discussed elsewhere in this book). Salsify is yet another essentially wild (perhaps less so than the other two) species of the sunflower family that is cultivated for its edible root.

Description and taxonomy Scorzonera is a perennial herbaceous plant native to central and southern Europe, including the southern parts of Russia and neighboring regions. Cultivated plants are essentially unchanged from the wild form. Scorzonera is grown as an annual or biennial, mainly for the long, tapering black-skinned, white-fleshed taproot. The leaves are sometimes eaten as a potherb (Bailey and Bailey 1976; Tutin et al. 1976). Scorzonera was collected from the wild until the 16th century. During the Middle Ages, it became one of the most important vegetables in Europe. The Spanish began to cultivate scorzonera in the 18th century, and its use spread. This vegetable fell out of favor during the Victorian Era, mainly because it became fashionable to peel away the “dirty” black skin (Halpin 1978). As noted

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below, the skin gives this vegetable its distinctive attractive taste and should not be removed until after the root is cooked.

Uses Scorzonera is eaten as a cooked vegetable and is also canned, bottled, and frozen in Europe. Vulsteke and Calus (1990) described the canning and freezing of scorzonera. When scorzonera is canned using immature roots that are processed immediately, the inulin in the roots crystallizes, causing a crust on the roots. The inulin content decreases as harvesting is postponed or as the storage period is prolonged, leading to little chance of crystallization after canning of mature roots. It has been observed that different European cultivars vary in their inulin content. To avoid the problem, scorzonera is increasingly marketed frozen, because crystallization does not occur. Note that inulin-containing vegetables like scorzonera can give some people gas if eaten in large quantities (Richardson 1990). For home use, the roots with the black skin left on are washed and boiled up to 45 min, until tender. The skin imparts the distinctive flavor to this vegetable. The roots of the related salsify, Tragopogon porrifolius L., are also eaten, but the flavor of scorzonera roots is more highly prized (MacLeod and Ames 1991). Lemon or vinegar should be added to the water to prevent discoloration, especially if the roots are not consumed immediately. The roots are best peeled, after cooking, and eaten with butter, or fried, baked, or added to soup (Halpin 1978; Buishand et al. 1986). The leaves of scorzonera are also sometimes eaten in salads (Bailey and Bailey 1976). Example recipes

Fried scorzonera à la George (Buishand et al. 1986) Salsifis with scallops (Richardson 1990) Scorzonera fritters (Organ 1960) Scorzonera in cream (Schneider 1986) Scorzonera vinaigrette (Schneider 1986)

Importance Scorzonera is mainly grown in Europe. In 1987, the combined production of scorzonera and salsify (Tragopogon porrifolius) was 69 000 t from 3800 ha in Europe (Hinton 1991).1 No report seems available on scorzonera production or use in Canada, and it is probable that there is scanty if any commercial production.


1

Scorzonera grows well in a loose, sandy loam soil, deeply cultivated to allow the long, tapering roots to develop. High organic matter content promotes nutrient availability and retains water (Halpin 1978).

Separate statistics are unavailable for these similar vegetables.

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Climate

Scorzonera is a hardy perennial. The plants overwinter as roots and new leaves grow during the second, flowering season. Irrigation is beneficial during dry periods, especially if the substrate is sandy.


Scorzonera is propagated by seeds, which are planted outdoors in the spring.

Harvest and storage

The roots are ready for harvest after one growing season. They are hardy and can be left in the ground overwinter for spring harvest. Scorzonera roots may be rather brittle at maturity, requiring care when digging them up (Halpin 1978). Roots that are not quite ripe can be stored for up to 4 months at 0–1°C with high humidity (Buishand et al. 1986).

Example cultivars

Some cultivars are recognized in Europe but are unavailable in Canada. This vegetable appears occasionally in Canadian garden catalogs as “black salsify” or “black-skinned salsify.” Bettencourt and Konopka (1990) listed institutions in various countries conserving scorzonera germplasm.

Additional notes Because scorzonera roots contain inulin, they are usable by diabetics who can ingest the roots as a source of carbohydrates. Inulin is responsible for the sweet flavor of the roots (Halpin 1978). (For more information on inulin, see “Uses” for Jerusalem artichoke, Helianthus tuberosus L.) Curiosities

In the Middle Ages scorzonera was regarded as an antidote to snake bite. Indeed, the name may be derived from either the Spanish “escorzo” or old French “scorzon,” both meaning serpent. During the Middle Ages, scorzonera was considered a useful tonic and remedy for smallpox. King Louis XIV of France reputedly grew large quantities of scorzonera in his gardens.

Problems and potential Scorzonera is likely to remain a little-used vegetable in Canada, grown mainly as a novelty of home gardens. It will perhaps be occasionally found in local markets. Because it is essentially a wild plant, there is considerable potential for selection. However, there does not seem much prospect for a market that would justify the breeding work required.


Sium Skirret Umbelliferae (Apiaceae) Carrot family Ombellifères, famille de la carotte

Genus notes Sium contains about 10 aromatic perennial species of the Northern Hemisphere and Africa (Bailey and Bailey 1976). One species, discussed below, is cultivated for its edible roots and blanched shoots.

Names Scientific (Latin) name: Sium sisarum L. English common name: skirret French common name: chervis (m) Also: chervi, berle des potagers

Description and taxonomy Skirret is a herbaceous perennial that is generally cultivated as an annual. The name is derived from the Dutch “suikerwortel,” meaning sugar root. In Scotland it is called “crummock,” and in Germany “Zuckerwurzel” (Halpin 1978). The cultivated form, var. sisarum (Tutin et al. 1968), perhaps originated in southern Siberia or northern Iran (Péron 1989b). It is now found as a ruderal in damp places in Asia, parts of the Middle East, central Europe, and northern Italy (Tutin et al. 1968; Schultze-Motel 1986). Skirret produces thin, branched roots, that grow in a cluster joined at a central crown. The edible roots are wrinkled and have firm, white, aromatic, sweet flesh. Skirret was an ancient vegetable familiar in parts of Asia as well as in classical Rome. During the 15th century it gained wide acceptance in Europe and by the 17th and 18th centuries it ranked as one of the major kitchen vegetables in English and American gardens. However, it fell out of favor and was replaced by carrot, salsify, and parsnip. Apparently its use as a blanched vegetable was largely unknown. Oriental countries still regard skirret as a useful vegetable (Halpin 1978; Péron 1989b).

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The wild form, var. lancifolium (Bieb.) Thell., is found in parts of Asia (Tutin et al. 1968).

Uses Skirret roots are scrubbed, cut into suitable lengths, boiled, and served like parsnips or carrots. The roots can be stewed, baked, batter-fried, or creamed. Skirret can also be grated and used raw in salads (Halpin 1978). The blanched sprouts are sometimes used as a vegetable, either boiled or baked, like Belgian endive, Cichorium intybus L. (Péron 1989b). Example recipe

Glazed skirret (Halpin 1978)

Importance No statistical information is available on the economic importance of skirret. It is used occasionally in a few Asian countries such as Korea and Mongolia (Buishand et al. 1986). Although this vegetable may not be used currently in Canada, it has potential value both as an alternative to more traditional root crops, and for its etiolated sprouts.


A well-manured sandy loam is ideal for skirret, but it will also grow well in rich muck soils. The soil should be high in organic matter (Halpin 1978).

Climate

Skirret is a hardy perennial, well-adapted to cool temperatures. It should be grown in direct sunlight. Additional water is beneficial during dry periods (Halpin 1978).


Plants are usually raised initially from seeds, which are hard-coated and therefore slow to germinate. The soil must be kept moist until germination occurs. The young plants should be thinned to a spacing of 20–30 cm at the 4–5 leaf stage. Skirret can also be propagated by offsets (side shoots) that develop at the base of the plant and produce, at their base, a network of bunched roots. These can be gathered at any time and planted (Halpin 1978; Péron 1989b).

Harvest and storage

The roots are ready for harvest by mid autumn. Like many other root crops, skirret tastes sweeter after a period of cool temperatures. The roots are considered hardy so that they may be left in the ground overwinter and dug up in the early spring before new growth develops. If left too long, they become woody and loose flavor. The excavated roots may be used fresh or they can be stored at 0°C and a relative humidity of 80–90%. The roots, which should not be allowed to freeze, are washed before use.

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Studies in France (Péron 1989b) have shown that the etiolated petioles may be blanched in the same manner as witloof chicory (Cichorium intybus) or sea kale (Crambe maritima L.). The roots are excavated in the fall, placed in a container, and covered with sandy soil. The soil is kept moist in a cool place away from light. Alternatively, the roots could be heavily mulched outdoors and left overwinter. In the spring, a pot or other lightproof container is placed over each plant when new growth first appears. The blanched petioles are harvested when they are 10–12 cm tall. Cultivars

Skirret does not seem to be available in Canadian garden catalogs, but seeds can be obtained from sources in Britain and the United States.

Additional notes Skirret roots are rich in glucosides, notably sucrose, constituting 65% of the dry matter (Leclerc and Péron 1989). Because of the sugar content the roots were used as a substitute for a type of distilled potato drink in Germany (Schultze-Motel 1986). The etiolated shoots compare in nutritional value to other leafy or sprout vegetables and are rich in aromatic substances. The sprouts have a higher vitamin level than the roots, and greenhouse-grown sprouts have higher vitamin content than field-grown sprouts (Leclerc and Péron 1989; Péron 1989b). Curiosities

The Roman Emperor Tiberius (42 B.C. to A.D. 37) is said to have received tributes of skirret roots from the warring Germans. In medieval times, skirret was regarded as a beneficial herb capable of curing everything from hiccups to frigidity (Halpin 1978). The generic name Sium is from the Celtic “siu,” meaning water, in recognition of the moist native habitats preferred by members of this genus (Grieve 1978).

Problems and potential Because of competition from several well-established, tastier, more-succulent root crops, this vegetable has limited potential for market expansion; it is likely to remain a novelty of the home garden.

Selected references Halpin 1978; Péron 1989b.

Solanum Solanum crops Solanaceae Potato family Solanacées, famille de la pomme de terre

Genus notes The worldwide genus Solanum, with perhaps 1700 species, is one of the largest and most diverse of all plant genera. The species are annual or perennial herbs, vines, shrubs or, rarely, trees. Solanum is regarded as a taxonomically difficult genus (Bailey and Bailey 1976). It includes important food plants, medicinal plants, and many ornamental species used in gardens and greenhouses (Hawkes et al. 1979; Jaeger and Hepper 1986; Burton 1989; Hawkes 1990), as noted below. Various taxonomic treatments of Solanum section Petota Dumort, which includes the potato and more than 200 related wild species, were reviewed by Spooner and van den Berg (1992). Important food plants: S. tuberosum L., potato, and S. melongena L., eggplant, both discussed in detail. Tuber-bearing plants closely related to the potato: S. ajanhuiri Juz. & Buk., S. chaucha Juz. & Buk., S. curtilobum Juz. & Buk., S. juzepczukii Buk., S. phureja Juz. & Buk., and S. stenotomum Juz. & Buk., all cultivated locally in the Andes. Tropical fruit plants: S. muricatum Ait, pepino; S. quitoense Lam, naranjilla; and S. ethiopicum, L. (including S. gilo Raddi), a complex of cultivated forms including scarlet eggplant, gilo, kumba, and shum S. lasiocarpum Dun., “Ma uek” (Thailanese) S. burbankii Bitt., wonderberry S. nigrum L. cultivar Garden Huckleberry, available in Canada.

Tropical vegetable plants: S. sessiliflorum Dunal, cocona or peach tomato, which looks like an eggplant but has fruit resembling a tomato and has been recognized by the National Academy of Sciences of the United States as one of 36 underused tropical plants of promising economic value (Salick 1989, 1992). Pharmaceuticals: S. marginatum L.f., cultivated for steroids.

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Eggplant

Names Scientific (Latin) name: Solanum melongena L. English common name: eggplant Also: aubergine, Jew’s apple, mad apple, melongene French common name: aubergine (f) [In Europe, eggplant is usually known as aubergine, both in English and French.]

Description and taxonomy The taxonomy of S. melongena and related species is somewhat contentious (for key papers see Khan 1979, Lester and Hasan 1990, and Sakata et al. 1991). Wild forms of S. melongena are found in fields and fallow areas in Asia. Solanum insanum L., considered a secondary weedy derivative of the cultigen, occurs in India. Solanum cumingii Dun., thought to be the weedy ancestral form of eggplant, grows in IndoChina. Lester and Hasan (1990) concluded that these “species” belong to a single biological species encompassing both cultigens and weedy forms. They proposed that both these wild forms should be treated as subspecies or varieties of S. melongena but did not present a formal classification. Eggplant has two centres of origin. India is probably the primary area for the large-fruited cultivars (now grown worldwide); China is associated with the smaller-fruited cultivars, considered to be more primitive than the former (Lester and Hasan 1990). Eggplant has been known in China since the 5th century B.C. but was not known in ancient Greece or Rome. Seeds of eggplant were brought westward from China about 1500 years ago. The Moors are thought to have introduced eggplant to Spain around 1200 A.D. By the Middle Ages all the colors of fruits that occur today were available. Subsequent domestication has been largely concerned with selection of larger fruits. Several cultivars were known in Europe and North America by the mid 1800s (Simmonds 1976; Nonnecke 1989). In eastern Asia, slender, sweet-podded types have been bred. Although eggplant is mainly used for food, ornamental eggplants have also been bred.

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Uses Eggplant is a well-known cooked vegetable, with a distinctive taste that is frequently either loved or disliked. The bitterness of some varieties can be removed by sprinkling the sliced fruits with salt and removing the moisture extracted by the salt by rinsing and drying the slices. Example recipes

Aubergines and lamb (Buishand et al. 1986) Aubergines with anchovies (Organ 1960) Caponata (for antipasto) (Morash 1982) Eggplant lasagna (Ornish 1990) Eggplant parmesan (Morash 1982) Eggplant with tomatoes, saffron, and garlic (Levy 1987) Eggplant, pasta, and grilled pepper salad (Schneider 1986) Grilled eggplant with fresh herbs (Levy 1987) Imam bayildi (fried eggplant dish) (Morash 1982) Mini eggplant hors d’oeuvre (Richardson 1990) Moussaka (with lamb) (Morash 1982) Ratatouille (Tudge 1980) Sautéed eggplant with Mediterranean vegetables (Morash 1982) Sicilian eggplant rolls (Schneider 1986) Spiced Oriental eggplant (Richardson 1990) Stuffed eggplant with pine nut pilaf and tomato curry sauce (Levy 1987) Vegetarian stuffed eggplant shells (Morash 1982) Yard-long bean, eggplant, and tomato stew with mint dill (Schneider 1986)

Importance Worldwide, over 4 000 000 t of eggplant fruits are often harvested annually, nearly half from China. Eggplants are particularly popular in Asia, but they are also a staple in North Africa from Egypt to Morocco. Europe often produces more than 500 000 t annually (Hinton 1991). By comparison, North America produces only about 70 000 yearly (Nonnecke 1989). Eggplant is a minor crop in Canada. In 1991, 8210 t of imported eggplant fruits were handled in major Canadian markets; domestic production was only 536 t, which accounted for about 6.5% of total eggplant fruits used (Anonymous 1992a). In 1992, 421 t of domestic eggplants were unloaded in 10 major Canadian markets (Anonymous 1993a). Limited area is devoted to eggplant production in Ontario, with a brief market supply in August and early September. Small amounts of eggplant are grown in other parts of Canada for local markets.


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Eggplant does best in warm, sandy loamy soil with high organic matter. The soil should be cultivated deeply to facilitate root penetration.

Climate

Eggplant, a perennial that is grown as an annual, requires warmth and is sensitive to cold. However, many cultivars have been bred that are able to tolerate summers in southern Canada. The optimum temperature range for germination is 24–32°C with the minimum at 15.5°C and maximum at 35°C. For best growth, eggplant requires temperatures of 21–29°C with a minimum of 18°C, for at least 2 months for most cultivars. Eggplant also needs a steady supply of moisture for production of quality fruits. Irrigation is frequently provided (Nonnecke 1989), and drainage must be adequate.


Eggplant is grown from seeds, which are slow to germinate, resulting in a long period of plant emergence. In Canada, seeds are started indoors in greenhouses or in heated frames 8–10 weeks before transplanting. For commercial operations, some plants may be imported bare-rooted from the southern United States, as are tomatoes. Frequent shallow cultivation may be necessary to control weeds. Rouhani et al. (1987) studied the effects of the number of lateral roots on plant growth and fruit production in eggplants. The vegetative growth, early fruit maturity, and total fruit production were dependent on the number of lateral roots (optimum number of 12–16) on an eggplant seedling at time of transplanting. This criterion of number of lateral roots should be used in selecting high-quality seedlings.

Harvest and storage

Eggplants are ready for harvest when fully formed and before seeds have begun to change color. Harvest is by a succession of hand pickings as the fruits mature. Mature fruits are firm, heavy, and glistening, with the calyx green and fresh. Hydro-cooling is not recommended because it is slow, resulting in possible water spots on the fruits; neither should ice be placed around the fruit. Postharvest chilling damage is caused when plants that were growing in hot temperatures are chilled rapidly. The fruits are precooled and held at a temperature of 10–12°C with a relative humidity of 95% (Nonnecke 1989). Under these conditions they store well for up to 10 days, before they need to be delivered to stores.

Example cultivars

International standards of quality and marketing of eggplant fruits were described by Asiedu et al. (1987). The fruits have been

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separated into two classes, elongated and globus (rounded), and examples of cultivars in each class follow: Elongated fruits:

dark fruits: Classy Chassis, Dusky, Jersey King, Ichiban, Long Tom, Vernal white fruits: Casper bicolored fruits: Italian Pink Bicolor Globus fruits:

Baby Bell, Blacknite Bettencourt and Konopka (1990) listed the world’s repositories of eggplant germplasm. Facciola (1990) provided an extensive description of eggplant cultivars available in the United States.


The name “eggplant” was coined from the resemblance to eggs of the small-fruited forms of China. Some white-fruited ornamental eggplants available today have strikingly egglike fruit. Like the tomato, the eggplant was once called the love apple in Europe and was thought to be an aphrodisiac. Ladies in the high society of China once made black dye from dark eggplant skins and used it to stain their teeth to a black lustre.

Problems and potential Domestic production currently accounts for a small amount of total eggplant consumption in Canada, so that there is obvious potential for increased supply. However, eggplant has a limited production period (mid August and early September) when grown outdoors. There is a steady demand for the imported fruits throughout the year as demonstrated by the tonnage of eggplants handled at major Canadian markets, but imports are reduced during the short domestic season (Anonymous 1992a). Eggplant is a crop that is grown indoors in some countries. For example, 75 ha of eggplant were recently grown indoors (91% hydroponically) in Holland (Adams 1990). Possibilities exist for growing eggplants indoors in Canada. However, eggplant may have to become more popular before producers will consider adding it to the traditional greenhouse vegetables of tomatoes and cucumbers.

Selected references Anonymous 1987; Nonnecke 1989; Lester and Hasan 1990.


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Potato

Names Scientific (Latin) name: Solanum tuberosum L. English common name: potato Also: white potato, Irish potato French common name: pomme de terre (f) [To avoid: patate (Boivin 1992).]

Description and taxonomy In the Andes of South America, as many as eight different potato species are cultivated, although in North America only S. tuberosum is grown commercially (Jothns 1982). The common potato is a herbaceous perennial plant, 0.5–1 m high, with small, attractive flowers. The fruits are green or purplish-green berries 1.3–2 cm in diameter, but are absent in many cultivars. The berries are quite poisonous, and indeed the only edible part of a potato plant is the potatoes. Most potato cultivars are sterile, incapable of producing true seeds. The potato plant is grown as an annual in areas where frost occurs. The potato itself is a tuber—an enlarged storage organ produced from an underground stem (Kadam et al. 1991). There are two cultivated subspecies (Grun 1990), as follows: subsp. tuberosum, originally from the coast of southern Chile and now cultivated worldwide, arose from a cross between subsp. andigena and an unknown species; subsp. andigena Hawkes, cultivated in the Andes of South America, has been introduced into Central America, Mexico, and the Canary Islands. It likely arose under cultivation as a natural hybrid of the cultivated S. stenotomum Juz. & Buk. and the weedy S. sparsipilum (Bitt.) Juz. & Buk. This subspecies occurs in a vast range of forms, and with a diversity of flower colors and tuber shapes, colors, and patterning vastly greater than those of the conventional potato (subsp. tuberosum). It has been claimed that of all crops potato has the largest number of related wild species (Hawkes 1990), not only the other 235 species of Solanum section Petota (also known as section Tuberarium; some specialists recognize fewer species), but also the many other species of the huge genus.

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The potato is thought to have arisen either in a single area of domestication in the central Andes, or also independently in Chile. The earliest known remains of cultivated potato, originating near Lima, Peru, were dated at 7000 B.C. At that time potato was preserved in food stores in a freeze-dried form, (known as “chuño”), that can only occur in high, cold mountains. The practice of preserving potatoes by freeze-drying is carried on to this day. The earliest known remains of wild potato, dated at 13 000 B.C., come from southern Chile. So-called “moche” ceramic pots, combining potato and human themes, were found through most Andean cultures after the time of Christ. The first written mention of potato by Europeans was by the Spanish in Peru around 1550. Subspecies andigena was introduced to Europe (in Spain) about 1570 (Brown 1993). Purchases were confined to December and January each year, lending weight to the interpretation that they were the short-day-adapted subsp. andigena, which forms tubers during the short days at the end of the year (Hawkes and Francisco-Ortega 1992). Before the end of that century the potato had spread through much of western Europe. Potato was introduced by Europeans to North America around 1621 and was also taken to India, China, Japan, and Africa by the end of the 1600s. The fungus Phytophthora infestans, which causes late potato blight, was responsible for the Great Irish Potato Famine (1845–1848). As a result of the famine, about 1 million people died, and 2.5 million emigrated between 1845 and 1860 largely to North America. Subspecies andigena was essentially eliminated in Europe by that disease. Subspecies tuberosum was introduced from Chile to North America and Europe in the late 1800s. It filled the vacated agricultural niche of subsp. andigenea and has since become the dominant potato worldwide (Burton 1989; Lisinska and Leszczynski 1989; Grun 1990; Hawkes 1990).

Uses Potato crops are used as fresh table food and served separately baked, boiled, mashed, and roasted, or combined with other ingredients in soups, stews, chowder, and dumplings. Increasingly potatoes are processed into a large variety of foods such as french fries and potato chips, or are dehydrated, flaked, granulated, canned, and frozen (Nonneke 1989; Salunkhe et al. 1989). Potatoes are also used as a raw material for production of alcohol. New or early potatoes are dug before full maturity and marketed quickly. They do not stand rough handling as well as the late crop and are more subject to injury. By contrast, potatoes of the late crop are usually more mature when dug and are often stored and shipped to market during the winter and spring. Culinary quality of potatoes is determined particularly by dry-matter content. Potatoes of high dry-matter content are mealy and preferred for baking. When the dry-matter content is high, however, potatoes may slough apart when boiled. Accordingly, potatoes of


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higher density are more suitable for baking than for boiling. Tubers that float in a brine made by dissolving 120 g of table salt in 1 L of water (1 lb/gal) are best suited for frying or boiling, whereas tubers that sink are suitable for baking. Example recipes

Arugula, potato, and leek soup (Schneider 1986) Blender potato pancakes (Morash 1982) Lynn’s chocolate potato cake (Morash 1982) Potato Gnocchi (dumplings) (Morash 1982) Potato gratin à la Savoyarde (Morash 1982) Potato-pepper salad à la Provençale (Levy 1987) Straw mat potatoes (Morash 1982) Summer potato and green bean salad (Levy 1987) Swedish potato and anchovy casserole (Morash 1982)

Importance The potato is one of the major food crops of the world (exceeded only by wheat, rice, and corn in world production for human consumption) and is superior (per unit area per unit time) to every other food crop in its ability to produce human food. It produces more dry matter and protein per unit area than the major cereal crops, although three times as much raw potato would have to be eaten to achieve equivalent energy to that of cereals (Salunkhe et al. 1989). World production of potato sometimes exceeds 300 million tonnes annually (Beukema and van der Zaag 1990). The former Soviet Union produces the largest amount of potatoes, followed closely by Poland and the United States. Potatoes are by far the most important vegetable crop grown in Canada, with a farm value of about a half billion dollars, representing 40% of the total for vegetables. About 50% of production occurs in the Atlantic provinces, mostly from Prince Edward Island. Canada is a net trade exporter of potatoes and its potato trade surplus grew over the 1980s. Exports of processed potatoes, particularly frozen french fries, have grown substantially since the mid 1980s. Domestic producers maintained about 90% of the total market and 95% or more of the processed market during the 1980s (Coleman et al. 1991).


Potatoes have wide soil type and pH tolerances, providing that there is sufficient organic matter and drainage. Soil should be 60–100 cm deep to accommodate the roots. Sandy soils with a pH of 5.5–6.0 are desirable. Maintaining the soil near pH 5.5 assists in controlling scab in the more susceptible white-skinned varieties, whereas a pH of 5.5–6.0 is recommended for the russet class of varieties. Higher pH provides a suitable environment for the scab-causing organism to multiply rapidly. Growing potatoes in the same soil year after year

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encourages diseases and pests, although particular potato varieties are resistant to some diseases (Asiedu et al. 1987). Crop rotation is beneficial. Climate

Potato is a cool-season plant, although sensitive to frost. Optimum growth occurs when air temperature is between 16–20°C, decreases above 20°C, and stops at 29°C. Tubers develop best at 12°C. These temperatures vary slightly depending on the cultivar (Asiedu et al. 1987; Nonnecke 1989). Most commonly cultivated varieties of the potato are photoperiodically adapted to flower during long days, although some varieties mature as days get shorter in the fall.


Although potatoes can be propagated from seeds, they are normally grown from disease-free certified stock, called “seed potatoes,” that are simply potatoes. Seed potato tubers have one or more “eyes,” i.e., clusters of modified buds, and it is necessary to have at least one eye in each piece used for propagation. The Plant Health Directorate of Agriculture and Agri-Food Canada is responsible for inspecting and certifying seed potatoes in Canada. All seed lots are laboratory-tested prior to planting, and a minimum of three field tests are required for the Elite class of potatoes, two for the Foundation and Certified classes. Zero tolerance to disease is strictly enforced (Asiedu et al. 1987; Perley 1990). It is highly recommended that home gardeners also use certified seed potatoes, and not table potatoes bought in stores, to ensure a satisfactory crop and avoid spreading viruses (Chong 1980). Seed potato tubers are cut into several pieces and planted mechanically. Soil around the plants is cultivated several times during growth, and soil is hilled up around the plants to protect the tubers formed near the soil surface. To encourage the tubers to mature, the potato plants are either mechanically knocked down to stop their growth or chemically killed with desiccants. Early maturing cultivars are rarely killed because top growth is relatively light (Nonnecke 1989).

Harvest and storage

Commercial potatoes are harvested mechanically. Although huge volumes of potatoes can be harvested efficiently, damage from bruising and cuts reduces quality. Once tubers are in trucks or bins, further damage is probable unless they are carefully handled and unloaded. Temperature affects the ease with which potatoes bruise during harvest damage; temperatures of 5–7°C are associated with 25–30% of bruising as compared to only 5% damage at 16–20°C. Potatoes should not be harvested if soil temperature is below 4°C. Controlling temperature is the single, most important factor in effective potato storage. Respiration, water loss, relative humidity, and development of disease all depend on temperature. Curing is essential for potatoes destined for table or seed use. A period of 10–14 days at


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13–16°C and a relative humidity of 90–95% is recommended. Before curing, recently harvested potatoes that are either very warm (above 20°C) or very cold (below 7°C) should be cooled or warmed at the rate of 2–3°C per day until the desired temperature is reached. Following curing, potatoes enter a period of dormancy, during which they will not sprout and when tuber quality is at its peak. Once potatoes are cured, the rate of cooling and final holding temperature are set depending on the end use of the crop. Seed potatoes are cooled gradually by 1°C every 1–2 days and are held at 3–4°C. This temperature must be maintained because fluctuating temperatures shorten dormancy. Table potatoes are cooled by 1°C every 3–4 days and are held at 4.5–5.5°C. This slower rate of cooling prevents excess buildup of sugars, which affects cooking and eating quality. Processing potatoes have special requirements. To prevent undesirable sugars from accumulating, the temperature is dropped slowly by 1°C per week. For short to intermediate storage, processing potatoes are held above 7.2°C. Potatoes destined for french fries before Christmas can be cooled to 10°C. Potato chip stock is stored at 10–12°C. For storage until January and up until early May, both french fry and chip stock can be held at 8–10°C. For longer storage it may be beneficial to cool the tubers to 4°C and then raise the temperature gradually to 13–15.5°C, 4–6 weeks prior to use (some varieties have different requirements). Relative humidity should be maintained at 92–97% during storage. Before handling, potatoes should be warmed to at least 7.2°C to prevent bruising and black spots forming. Sprout inhibitors are sometimes used for potatoes intended for the late fresh or processing markets. (A problem that developed from use of such inhibitors is discussed in “Curiosities”.) Sprouting accelerates water loss and results in smaller volume of saleable tuber (Asiedu et al. 1987; Nonnecke 1989). Example cultivars

In Canada, seed potatoes are sold as early, mid season, or late. There are also color differences in the skin and flesh of the tubers. Early season: Eramosa, Erik, Irish Cobbler, Onway, Norland, Warba, Yukon Gold (the first Canadian-bred yellow-fleshed variety) Mid-season: Acadia Russet, Kerry Blue, Longlac, Purple Viking, Red Gold, Rideau Late season: Banana, Bintje, Blue Mac, Desiree, Green Mountain, Kennebec, Red Pontiac, Russet Burbank, Sebago The recently introduced cultivar Explorer is grown from true seed (not the “seed potatoes” that are tubers). Reviews of potato cultivars in relation to use and economic value in Canada are provided annually by Agriculture and Agri-Food Canada (e.g., Anonymous 1992b; Anonymous 1994a). Russet Burbank is by far the most popular

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cultivar with Superior, Kennebec, and Shepody next in importance. Russet Burbank is also the most popular cultivar in the United States. Bettencourt and Konopka (1990) listed world repositories of genetic resources of potatoes located in plant gene resource banks. The world’s largest collections of potato germplasm are at the International Potato Center, Lima, Peru (with about 5000 collections), and at Sturgeon Bay, Wisconsin (also with about 5000 accessions). Facciola (1990) provided an extensive description of potato cultivars available in the United States. Major sources of Canadian potato cultivars are the Bon Accord Elite Seed Potato Farm run by the New Brunswick Department of Agriculture, Benton Ridge of Agriculture and Agri-Food Canada in New Brunswick, and the Fox Island Elite Seed Potato Farm of the Prince Edward Island Department of Agriculture. Agriculture and Agri-Food Canada maintains a germplasm collection at Fredericton, and virus-free collections are also maintained at Vancouver and La Pocatière. Canadian conservation of heirloom varieties that are no longer of commercial interest in discussed by Pittenger (1994).

Additional notes In a recent review of potato toxins, Sharma and Salunke (1989) noted that the entire plant, including the tubers, contains toxic glycoalkaloids, mainly α-solanine and α-chaconine, which irritate the gastrointestinal tract and impair the nervous system. However, the quantities in the tubers are usually harmless unless the latter have been exposed to light or mechanically damaged. (Even without exposure to light, the cultivar Lenape, developed in the 1960s, produced natural levels of the toxins higher than 30 mg/100 g; accordingly, it was never released to growers.) Because tubers photosynthesize in the presence of light, causing the potatoes to become green, the presence of green coloration in potatoes is correlated with the amount of toxins (although photosynthesis and the metabolic pathway synthesizing the toxins are independent). Another indicator of the presence of the toxin is bitterness. Potatoes are now screened for toxin levels, which must be below 20 mg/100 g. Levels above 14 mg/100 g are bitter. These glycosides are not destroyed by normal cooking. Care should be taken to store potatoes in lightproof containers such as paper bags. Green-colored potatoes should be discarded. Because the toxins concentrate in the skin and eyes of the potatoes, peelings and sprouts destined for compost should be buried to keep them out of sunlight so that animals digging up the remains will not be poisoned. Curiosities

The word potato is believed to have been derived from the Spanish “patata,” meaning sweet potato. Toxic levels of glycoalkaloids are present in wild potatoes of the southern United States, Mexico, and South America. Indians of these regions learned to detoxify these potatoes and reduce the bitterness due to the glycoalkaloids by boiling the potatoes in a


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slurry of edible clays. Silicates in the clays are believed to bind with the toxic compounds, thus neutralizing them (Johns 1982). In the early years of potato introduction in the Old World there was strong resistence against using it as food. One minister preaching against the potato stated that if God had intended it as food for man it would have been mentioned in the Bible. When the potato was first brought to Europe from Peru, there was violent opposition to it because it was thought to be poisonous, like other members of the Solanaceae family. The King of France set out to popularize the potato. He invited the aristocracy of Paris and such respected figures as Benjamin Franklin to a sumptuous all-potato dinner. Marie Antoinette even wore potato blossoms in her hair. When this failed to make the potato acceptable, he devised a clever scheme. On the outskirts of Paris, he planted a field of potatoes and had it guarded during the day by a troop of soldiers. He withdrew the guards at night with the result that, as he had predicted, the peasants would think the crop being guarded was of great value and would steal samples. These thefts from the King’s potato garden have been credited as an important reason why the potato became established all over France (Taylor 1965). Fredrick the Great of Prussia was another world leader who promoted the potato. It has been estimated that in the early 1840s, a working man in Ireland ate 5.5.–6.3 kg (12–14 lb) of potatoes daily (Langenheim and Thimann 1982). Apparently wild potato populations have been discovered in the mountains of British Columbia. These probably originated from discarded potatoes, which managed to reproduce independent of cultivation, although it has also been suggested that potatoes were introduced to B.C. by Indian tribes. The word “spud” refers to a spadelike tool. Because spades have been used for hundreds of years to dig potatoes, the term has come to apply also to potatoes. Potatoes come in a rainbow of colors (in addition to black and white), including purple, red, pink, green, gold, and yellow. Although the color of many potatoes is often only skin-deep and the flesh is white or whitish, some potatoes are colorful throughout. These include the cultivars All Blue, All Red, and Yukon Gold. Dogs sometimes like to dig up potatoes. One solution is to lay chicken wire flat on the ground over the potato patch. The dogs do not like the feel of wire under their feet and leave the potatoes alone. In 1992 the misspelling of potato as potatoe by the vice-president of the United States became a cause célèbre. A truly Canadian dish called poutine originated from the Bois-Francs area of the province of Quebec in the 1950s. The basic recipe consists of french fries, cheese curds, and gravy. Apparently poutine was created in the kitchen of a restaurant named “Lutin

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qui rit” (the laughing elf) located in Warwick, operated by Fernand Lachance. A musty off-flavor in frozen french fries made from Western Canadian Russet Burbank potatoes was detected by several North American food chains from 1983 to 1987 and threatened Canada’s $200-million french-fried potato industry. The problem was traced to the carrier of a commercial sprout inhibitor, which necessitated the control and monitoring of the inhibitor (Mazza and Pietrzak 1990). In promoting new uses for the “Irish spud,” Ireland’s Horticulture Board suggested that a sliced potato in a muslin bag can help remove bags under the eyes; a dried potato suspended from the neck is helpful for rheumatism; and chopped potatoes in warm water can remove stubborn wine stains at the bottom of a decanter. On August 31, 1987, in Williamsport Pennsylvania, a Double-A baseball game took place in which the entrance fee was a dollar and a potato. Dave Bresnahan of the Williamsport Bills of the Eastern League, a catcher with this Cleveland Indians farm club, sneaked a peeled potato into his mitt, and after catching a pitch, switched ball and potato. He hurled the potato to third base to pick off a runner, who ran home, where he was tagged out with the potato. The umpire realized later what had happened, and declared the runner safe. Mr. Bresnahan was taken out of the game by the team’s manager, fined $50.00, and subsequently released from the team. The incident has became one of the great tales of American baseball, and Mr. Bresnahan regularly receives potatoes with the request that he autograph them (Berkow 1997). In 1995 during Potato Week in Boise, Idaho, a swimming pool was filled with 37 850 L (10 000 gal) of mashed potatoes (Berkow 1997). It has been calculated that for every dollar invested in public research on potatoes in Canada over the period 1971 to 1995, a return of ten dollars has resulted (Anonymous 1997). Potato chips were invented in 1853 by Chef George Crum at a fashionable resort in Saratoga Springs, New York (Willard 1993). During the First World War, soldiers encountered elongated fried potato strips being sold by street vendors and in restaurants. The product came to be called “french fries” because the Belgians serving it commonly spoke French (Willard 1993). The potato strips were first parfried sufficiently to inactivate their enzymes, and then fried just before serving. After the war, this technique was adopted in North American restaurants, and today about one third of all potatoes are consumed as french fries in North America. During 1997, actor Paul Gross (R.C.M.P. Constable Benton Fraser in the popular television show Due South) repeatedly stated in an advertisement for his show that instant mashed potato flakes were invented by a Canadian, information apparently gleaned from internet trivia files which state this. Although it is true that Canadian scientists have originated important variations in the commercial development of quick-rehydrating dried mashed


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potatoes, United States scientists developed much of this industry and many of the relevant patents after World War II (Willard 1993). Since the Incas prepared freeze-dried dehydrated potatoes (chuno) perhaps 13,000 years ago, no nation can claim to have exclusively invented instant potato preparations. (Background information kindly furnished by B. Stark.) The potato has the distinction of being the first choice of scientists considering what food plants can be grown extra-terrestrially to feed space travellers. Its advantages include universal taste appeal, abundance of nutrients, slow release of energy, limited waste, and ease of preparation.

Problems and potential Potato is susceptible to a variety of viruses, fungi, bacteria, insects, and nematodes (Boiteau et al. 1987). Of primary concern for potato growers are potato diseases. A case of the potato virus PVYn in Ontario in 1990, and subsequent problems, highlights this issue. The seed potatoes were traced to Prince Edward Island. A survey was initiated in New Brunswick and three fields of the cultivar Atlantic tested positive and were destroyed through processing. The United States and other Canadian provinces banned importation of seed potatoes from four of Prince Edward Island’s six potato-growing districts because some fields in those districts were found to contain the virus. PVYn is an aphid-transmitted disease that has little effect on potatoes but severely affects tobacco crops. Seventeen farms on the island and eight more in New Brunswick were placed under quarantine and Agriculture and Agri-Food Canada launched a vigorous eradication campaign. Measures have included testing all seed potatoes and destroying any that are contaminated, banning planting of Atlantic potatoes, and requiring farmers to plant only certified seed. The loss to the Prince Edward Island potato industry was estimated to be in the order of $50 million (Grady 1991; Hinds 1992). By autumn 1992 the measures taken by Agriculture and Agri-Food Canada had been so successful that fewer than 30 fields in over 10 000 surveyed were infected. In late 1992 the United States Department of Agriculture indicated renewal of acceptance of seed potatoes from Canada. Potato blight is once again on a rampage throughout the world, with more virulent forms than were encountered during the infamous Irish potato famine (Anonymous 1996). The A1 strain of the fungus has been responsible for most infestations around the world. The A2 strain has been found to be responsible for several localized infestations since the 1980s. Scientists realized that the two strains had combined sexually in 1992 in British Columbia, producing extremely virulent strains (the fungus generally reproduces by asexual spores). Moreover, the resulting spores have a protective coat that enables them to survive, even over winter, unlike the asexual spores which cannot survive long. Late blight is increasingly resistant to fungicides, and this is necessitating greater use of fungicides, with the result that the

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potato has become the most chemically intensive food crop in the world (Anonymous 1996). Intensive efforts are underway to breed genetically resistant potatoes. Insects consume about 13% of crops on average (Small 1996), and pesticides are necessary to prevent even greater losses. Modern “integrated pest control” seeks to reduce the use of pesticides by a variety of techniques, particularly the breeding of insect-resistant cultivars (Duchesne and Boiteau 1995). Several insects, notably the Colorado Potato Beetle and aphids, are devastating pests of potatoes in eastern Canada. Aphids spread virus diseases in potatoes, and sublethal doses of some insecticides can cause aphids to become more active, increasing the spread of the viruses (Boiteau and Osborn 1996). In nature, a principal method by which plants protect themselves is by placing insect-repellent glands on the leaves and stems, and these glands can be transferred from wild species to cultivars by breeding. The glands secrete a sticky resin that is poisonous or tastes terrible, or acts like flypaper to trap and kill insects. A search for protective glands in the wild species offers considerable potential for reducing the need for pesticides, and research in this area is currently under way in Agriculture and Agri-Food Canada (Pelletier and Clark 1996). Genetic engineering is another important potential method of reducing the damage to potatoes caused by insects, without using insecticides. The NewLeaf potato has been engineered for resistance to the Colorado Potato


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Beetle. A so-called bt gene from a common soil bacterium (Bacillus thuringiensis) has been inserted into this potato, and the gene prompts the plant to produce a protein which is toxic to the insects (Pelletier et al. 1996). Potatoes are the leading vegetable crop in Canada and will remain so. This explains why great care is taken to protect the industry when it is threatened by problems such as described above. Prince Edward Island not only supplies table potatoes across Canada but also supplies seed potatoes across North America and to 15 other countries.

Selected references Hodgson et al. 1974; Chong 1980 ; Integrated Pest Management Manual Group 1986; Asiedu et al. 1987; Burton 1989; Beukema and van der Zaag 1990; Hawkes 1990; Anonymous 1992b; Dean 1994.

Spinacia Spinach Chenopodiaceae Goosefoot family Chénopodiacées, famille du chou gras

Genus notes The genus Spinacia is composed of four annual herbaceous species native to southwestern Asia (Bailey and Bailey 1976). The one cultivated species is discussed below.

Names Scientific (Latin) name: Spinacia oleracea L. English common name: spinach French common name: épinard (m) [Other plants cultivated for edible spinachlike leaves and called spinach include New Zealand spinach (Tetragonia tetragonioides (Pall.) O. Kuntze), Malabar spinach (Basella alba L.), and water spinach (Ipomaea aquatica Forsk.), all discussed in this book.]

Description and taxonomy Spinacia oleracea is a herbaceous annual plant that is now cultivated throughout the temperate parts of the world. Wild forms of spinach are not known. Two varieties of cultivated spinach are recognized, as follows (Bailey and Bailey 1976; Nicholson et al. 1975; Schultze-Motel 1986): var. inermis (Moench) Metzg., characterized by its rounded, smooth fruits, is known as round-seeded or summer spinach; var. oleracea, known as prickly seeded or winter spinach, has spiny fruits, and the plant is more spreading and branched than var. inermis. Cultivars grown in Canada are likely all derived from var. inermis, which is sown in spring or early summer for an early harvest. It is also sown in late summer for autumn harvest. Variety oleracea is

Spinacia (spinach)

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considered the more primitive form. It is used as a winter crop in warmer regions than found in most of Canada. Spinach has a complex floral biology, which is especially important for plant breeders. The plants are naturally dioecious (with separate male and female plants). Occasionally plants are monoecious (with male and female flowers on the same plant) or, rarely, possess perfect flowers (with both male and female organs). Four classes of spinach plants are recognized based on floral biology: extreme male: with small, bractlike inflorescence leaves vegetative male: similar to the above class but with well-developed inflorescence leaves monoecious: with mixtures of male and female flowers in the same inflorescence female: with female flowers only, borne in the axils of the inflorescence leaves. These types occur in both varieties of Spinacia but in different ratios. The extreme male class predominates in var. oleracea. The vegetative male class, which is the preferred plant type for cultivation because of its abundant leaves, predominates in var. inermis. The strong tendency of spinach to bolt in hot weather and under environmental stresses remains a chief difficulty, because flowering reduces leaf production. However, spinach has been selected for its response to temperature, and so-called “long-standing” types are resistant to bolting. Spinach has also been selected for leaf shape and habit. Different leaf characters include savoy (wrinkled), crushed, crumpled, semisavoy, and smooth. Spinach intended for processing is usually smooth, or sometimes semisavoy. The savoy cultivars are preferred for the fresh market (Nonnecke 1989). It has been suggested that cultivated spinach was first used in what is now Afghanistan and Tajikistan. Spinach was apparently unknown to the ancient Greeks and Romans. Chinese writings of A.D. 647 described spinach as originating from Nepal. The Moors brought the prickly fruited variety of spinach to Spain in A.D. 1100. The smooth-fruited variety arose later. Spinach spread to the rest of Europe and was well known in England and France by A.D. 1500. By 1806, at least three cultivars were being grown in North America. The first savoy cultivar was introduced in 1828 in America (Simmonds 1976; Nonnecke 1989). The “seeds” of spinach are technically one-seeded fruits. We follow popular usage in terming them seeds.

Uses Commercially, spinach is grown for the local market, and also for canning and freezing. Savoy cultivars of spinach are more suited to shipping than other variants, as the former pack less closely and consequently “heat” less readily. Savoy cultivars are also less inclined to wilt or yellow before being marketed. However, other varieties are

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more easily cleaned and prepared for canning and freezing. Spinach is a well-known potherb in the Western world, eaten cooked or raw. Example recipes

Bright-green spinach tart (Levy 1987) Crêpes à la Florentine (Owen 1978) Lasagne with spinach (Owen 1978) Onions stuffed with spinach (Levy 1987) Oysters and spinach in white butter sauce (Morash 1982) Rolled flank steak stuffed with spinach (Morash 1982) Spinach and fish paupiettes (Morash 1982) Spinach and lobster quiche (Owen 1978) Spinach koftas (Tudge 1980) Spinach soufflé (Morash 1982) Spinach, leek, and pumpkin pancakes (Levy 1987) Stir-fried spinach with ginger (Morash 1982) Turkey Florentine (Morash 1982)

Savoy spinach

Importance More than 80% of spinach consumed in Canada is imported (Dubé et al. 1990). In Canada, Ontario is the leading commercial spinach grower, followed by Quebec and British Columbia. Most of domestic production is sold in the fresh market (Coleman et al. 1991).


Spinach is sensitive to moderately acidic soils, preferring a pH range of 6.0–7.5. It is tolerant of soil type, as long as there is abundant organic matter and the soil is well cultivated. Muck soils are preferred over sandier soils, as this reduces the amount of grit that gets into spinach leaves, resulting in a cleaner product.

Climate

Spinach is very sensitive to daylength and temperature. It is a cool-season plant that grows best when the temperature is moderate. Abundant crops of leaves are produced only in early spring or autumn (or in winter in southern North America). A flower stalk is developed in late spring or summer as a response to increasing daylength, interrupting leaf growth. Spinach has been overwintered by commercial growers attempting to obtain an early spring crop, but damage to the crop generally occurs unless good protection is provided by snow cover or a blanket of straw, or both. Germination percentage is greatest at 5°C, but at this low temperature emergence takes about 23 days. Proportion of germination drops as temperature increases, but speed of emergence increases. For example, at 25°C, emergence occurs in 5 days, but the result is only 30% of maximum percentage obtainable.

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Spinach is propagated from seeds. Commercial spinach is direct-seeded using precision methods. In some areas spinach is simply broadcast-seeded onto beds. Seed is sown only 2–3 cm deep. The effect of soil temperature on germination rate is discussed above. Spinach is not usually thinned, although some growers generously space the seeds so that the plants will become large and leafy.

Harvest and storage

If hand-harvesting is practiced, regular picking of recently matured leaves of spinach is advisable to maximize quality. Commercially, mechanized harvesters are generally used to cut the plants just above soil level. Gourmet market spinach may be pulled by hand and individually wrapped along with the roots, to present an attractive product. The crop must be quickly hydrocooled to 0°C with high relative humidity to prevent shrivelling. Controlled storage with 10% CO2 prevents yellowing for up to 3 weeks at 5°C (Nonnecke 1989). A forced-air precooler has been developed at the Kentville Research Station of Agriculture and Agri-Food Canada in Nova Scotia. It rapidly removes heat from freshly harvested spinach, resulting in a dramatic decrease in rejected slimy shipments from 50% to 4% (Johnson 1992a).

Example cultivars

Savoy spinach: America, Longstanding Bloomsdale Dark Green, Vienna. Semisavoy spinach: Melody, Tyee. Plain-leaf spinach: Olympia, Symphony. Malo and Bourque (1992) described recent spinach cultivar trials in Montreal. Major germplasm collections of spinach are listed in Bettencourt and Konopka (1990). Facciola (1990) provided an extensive description of classes and cultivars available in the United States.


Spinach is the archetypical bad-tasting vegetable which, although “it’s good for you,” and although it is the tonic used by Popeye the sailor man to acquire miraculous strength, remains the most universally disliked vegetable by children in the Western world. So bad is spinach’s reputation that Webster’s Third International Dictionary gives as meanings for spinach, in addition to its being a potherb, “something repellant, obnoxious, or nonexistent … something spurious or unwanted … an untidy overgrowth … an inessential, irrelevant, or inharmonious excrescence …” Spinach is one of the very few cultivated crops that are dioecious (having separate male and female plants). Others are marihuana (Cannabis sativa L.), hop (Humulus lupulus L.), and date palm (Phoenix dactylifera L.). The Green Giant corporation’s entire spinach crop was wiped out by the 1989 San Francisco earthquake (Martin 1991).

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Problems and potential Spinach is a minor crop in Canada and is unlikely to increase notably in popularity. Domestic production is less than 20% of total spinach used in Canada (Coleman et al. 1991). Spinach is available domestically in the spring and fall with imports filling demand year-round. There is the potential for some greenhouse culture during the winter.


Taraxacum Dandelion Compositae (Asteraceae) Sunflower family Composées, famille de la marguerite

Genus notes Taraxacum contains 50–60 biennial or perennial herbaceous species, mostly native to the Northern Hemisphere (Bailey and Bailey 1976). A few species have been grown as ornamentals. Taraxacum kok-saghyz Rodin., Russian dandelion, has been grown in Russia and elsewhere as a source of rubber, derived from the plant latex (see “Curiosities”). Another species, cultivated for its edible greens, is discussed below.

Names Scientific (Latin) name: Taraxacum officinale Weber [See Small (1997) for a discussion of problems associated with this name] English common name: dandelion French common name: pissenlit (m) Also: dent-de-lion, dent de lion (See “Curiosities” for derivation of names.)

Description and taxonomy Dandelion is a herbaceous perennial, generally considered native to Europe and Asia (Bailey and Bailey 1976). The cultivated form is essentially unchanged from the wild form but has broader, more deeply lobed leaves than the latter. When cultivated for its edible leaves, dandelion is grown as an annual. Dandelion was used for centuries in Eurasia. In Europe, it was widely used as a potherb by the poor, who gathered it from the wild. It was also grown in a blanched form and used in salads (Millspaugh 1974), and the roots were used as a coffee substitute. Dandelion was brought to North America by early colonists as a potherb (some investigators think dandelion may be native to the northern United States [Zennie 1987]). During times of war and famine, dandelion was a much-valued vegetable (Halpin 1978; Splittstoesser 1990). It is now distributed throughout the world in temperate regions. In North America it is regarded as a serious weed of lawns. It occurs in all provinces and territories of Canada (Szczawinski and Turner 1978; Scoggan 1978–1979).

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Uses Dandelion leaves are used primarily as a cooked vegetable, although young leaves are sometimes eaten raw in salads (Zennie 1987). If wild dandelions are harvested, the leaves are best cooked in one or two changes of water. The crown of the plant (the central white portion of the rosette) can be dipped in batter and deep-fried. Dandelion roots can also be eaten after two changes of water. They can be consumed hot, or added cold to a salad (or even warm, as in one of the “Example recipes”). The roots can also be dried, roasted, and ground as a coffee substitute. The carbohydrates in the root are in the form of inulin, which is better than sucrose for diabetics (as discussed in “Uses” for Jerusalem artichoke, Helianthus tuberosus L.). Alcoholic beverages are made from dandelion, using flowers for wine and whole plants for beer (Szczawinski and Turner 1978). Example recipes

Adam’s winter salad (Szczawinski and Turner 1978) Creamed dandelion greens (Organ 1960) Dandelion coffee (Szczawinski and Turner 1978) Dandelion green noodles (Owen 1978) Dandelion punch (Turner and Szczawinski 1978) Dandelion salad (Buishand et al. 1986) Dandelion with hot bacon dressing (Halpin 1978) Dandelions in sour cream (Szczawinski and Turner 1978) Dandy-coffee, Vienna style (Turner and Szczawinski 1978) Felipe Rojas-Lombardi’s dandelions with Penn Dutch dressing (Schneider 1986) Oldtimer’s dandelion wine (Szczawinski and Turner 1978) Warm dandelion salad with mushrooms and poached eggs (Levy 1987)

Importance Dandelion is grown commercially in France (Szczawinski and Turner 1978). Production and importation figures for this vegetable in Canada are rarely available. In 1988, wholesalers in Toronto handled 111 t worth $397 000, while Montreal wholesalers handled 55 t valued at $198 000 (Anonymous 1989). These are rather large values for a plant that is normally considered to be merely a weed.


Dandelion will grow on just about any well-drained soil but performs best on rich, well-cultivated loams (Halpin 1978). It appears adapted to a wide range of pH values.

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Climate

Dandelion is a hardy perennial, well-adapted to all but the colder parts of Canada. Irrigation during dry periods is beneficial (Splittstoesser 1990).


Seeds are sown either in spring as early as the soil can be worked for summer and autumn use, or in late summer for harvest the following early spring. Dandelions should be thinned early as the taproots quickly become difficult to remove (Halpin 1978).

Harvest and storage

The cultivars sold are said to mature at about 90–95 days. However, leaving the plants this long before harvest may result in tougher, more-bitter leaves (Halpin 1978). Spring-planted dandelion can be harvested when the leaves are young and tender. Alternatively, the outer leaves, when 15–20 cm long, can be tied to blanch the inner leaves, 2–3 weeks before harvest. This results in a tender, inner heart, similar to Belgian endive. The plants can be left to overwinter (with a top mulch) and the first tender leaves picked in early spring. The plants with roots attached can be lifted for forcing at the end of the growing season. After removing dead or damaged outer leaves the roots are placed in a container with damp sand, and then the crown is covered with about 15 cm of additional damp sand. The container is placed in a warm location and within 2–3 weeks the dandelion tops will pierce the top of the sand. These new leaves can be harvested for 2–4 weeks; subsequently, removal of the sand reveals the rest of the blanched, tender leaves above the crown (Halpin 1978).

Example cultivars

Thick-leaved Improved, Verte de Montmogny. This vegetable is often sold in Canadian garden catalogs as “French dandelion” and may be listed under herbs. Wild dandelion can be used, but the selected cultivars are known not to be bitter and are therefore recommended (Halpin 1978; Szczawinski and Turner 1978).

Additional notes Dandelion greens are high in vitamin A, iron, calcium, phosphorus, and potassium and are one of the best dietary sources of copper. It is a valuable bee plant because the flowers bloom early in the spring, and at that time may be the only major source of nourishment for bees. Biological control studies at Agriculture Canada’s Harrow Research Station have shown that dandelions can protect tomato crops from Fusarium, a soil-borne fungus, that is a particular problem in commercial greenhouses. Research has shown that growing dandelions either as a companion crop or as a green manure reduces the risk of attack by the fungus. The mechanism by which this occurs has also been clarified. It has been noted that Fusarium does not compete well with other soil microorganisms and that the fungus requires elemental iron to thrive. Growing dandelions appears to increase the number of soil microorganisms; also dandelion residues contain cichoric acid, which ties up soil iron. Dandelion also contains polyphenols, which are natural fungicides. Dandelion also adds

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nutrients to the soil when it is plowed back in, and well-nourished plants generally have increased resistance to disease. Producers in British Columbia have grown dandelions to help protect their red-skinned greenhouse tomatoes (Jarvis 1990). Because dandelion is such a common weed, some will be tempted to test ‘Thick-leaved’ cultivar its edibility by harvesting nearby plants. One should always be aware of the danger of collecting herbicide-sprayed dandelions on lawns and roadsides. Curiosities

Millspaugh (1974) reported that in the early days of the United States, dandelion leaves were a favorite vegetable of the Digger and Apache Indians “who value them so highly that they scour the country for many days’ journeys in search of sufficient to appease their appetites. So great is their love for the plant, that the quantity consumed by a single individual exceeds belief.” Dandelion is considered by some to be an excellent pasture plant for cattle and is said to increase milk flow (Szczawinski and Turner 1978). Dandelions have been observed to flower in every month of the year (Zennie 1987). Economic difficulties in the newly constituted Russia have resulted in reconsideration of abandoned crops. Important among these is Taraxacum kok-saghyz Rodin., Russian dandelion, a source of rubber that may reduce dependence on rubber imports. The English name dandelion is a corruption of the French dent de lion, lion’s tooth, in reference to the coarsely toothed leaves. The French pissenlit, literally “wet-a-bed,” is a reference to the reputation of dandelion greens for stimulating the kidneys. Wet-a-bed was also an English name for dandelion.

Problems and potential Most people are prejudiced against dandelion as a vegetable because not only is it a bothersome weed of gardens and lawns but also it seems an improbable vegetable. Dandelion is likely to remain a plant used by Canadians whose cultural background has resulted in familiarity with its usage.

Selected references Halpin 1978; Szczawinski and Turner 1978; Small 1997.

Tetragonia New Zealand spinach Aizoaceae Ice-plant family (carpet-weed family, fig-marigold family) Aïzoacées, famille de la mollugine

Genus notes Tetragonia is composed of about 50 herbs and small shrubs native to Africa, east Asia, Australia, New Zealand, and southern temperate South America (Bailey and Bailey 1976). The one species used as a vegetable is discussed below. The taxonomic relationships of Tetragonia are controversial. Some authors treat this genus as a member of the family Aizoaceae (e.g., Cronquist 1981) with Tetragonia in the tribe Tetragonieae; others have segregated it and a few other genera into the family Tetragoniaceae (e.g., Bailey and Bailey 1976).

Names Scientific (Latin) name: Tetragonia tetragonioides (Pall.) O. Kuntze English common name: New Zealand spinach French common name: tétragone (f) Also: épinard de la Nouvelle-Zélande

Description and taxonomy New Zealand spinach is an annual herbaceous plant that is native to New Zealand, Australia, some Pacific islands, Japan, and southern South America (Bailey and Bailey 1976). Selections have been made resulting in plants with larger leaves than wild forms. Although the cultivated forms are used similarly to spinach (Spinacia oleracea L.), New Zealand spinach has the added benefit of continuing to grow well during hot weather. Unlike true spinach, which develops a compact rosette of leaves, New Zealand spinach produces a leafy, branching stem 10–20 cm tall and often covering an area more than 1 m in diameter. New Zealand spinach was found growing wild in New Zealand by Captain James Cook in 1770, and he subsequently observed it along the seacoast of southern and western Australia and Tasmania. (These wild forms have not been given separate taxonomic recognition.) It was reported as a “spinachlike” vegetable and was used by early

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Australian explorers. New Zealand spinach was introduced into Europe in the late 18th century.

Uses New Zealand spinach leaves are used like spinach. The leaves and young shoots are steamed with a little water until tender and consumed as a hot vegetable, or added to soups, stews, pastas, or meat dishes. The raw leaves can be used in salads (Tindall 1983; Yamaguchi 1983). The flavor is similar to, but milder than, common spinach. Example recipes

Cream of spinach soup (New Zealand spinach) (Morash 1982) Spinach crêpes (Morash 1982)

Importance New Zealand spinach is cultivated in most parts of the tropics and temperate regions as a minor crop (Cunningham et al. 1981; Tindall 1983; Yamaguchi 1983). In Canada it is mainly grown in home gardens. It is not clear how much New Zealand spinach is sold commercially in Canada, but the amount, if any, is clearly limited. It may be sold locally from market gardens, especially during hot summer months when true spinach is not at its best.


In its native habitat, New Zealand spinach grows on coastal sands, dunes, and stony beaches. This plant performs best on well-drained, sandy soils with considerable organic matter.

Climate

The succulent leaves of New Zealand spinach are well adapted to temperatures up to 35°C. The species also tolerates a considerable range of rainfall. Although most cultivars can withstand short periods of drought, irrigation during dry periods is beneficial.


Propagation is by so-called “seeds,” which are actually hard, dry, angular fruits about 8–10 mm long, each containing several true seeds (Yamaguchi 1983). The fruits are sown directly into the soil. Germination may be slow and erratic, requiring 2–3 weeks. Soaking the fruits for 24 h prior to sowing reduces germination time. Fruits may be sown indoors and transplanted (Tindall 1983). Occasional shallow weeding is beneficial.

Harvest and storage

New Zealand spinach is usually ready for harvest 40–60 days after emergence. The tender shoots, 15–20 cm long, are cut and consumed.

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After the first cutting, the plant produces upright branches that are used in subsequent harvests (Yamaguchi 1983). In the Phillipines, shoots are tied for market in bunches of about 20, weighing 0.5–0.75 kg, with tips at each end of the bunch (Tindall 1983). New Zealand spinach leaves do not yellow for up to 3 weeks in storage, if kept at 5°C with high relative humidity and CO2 at 7% (Nonnecke 1989). Example cultivar

New Zealand.

Additional notes New Zealand spinach contains soluble oxalates, which have poisoned livestock in parts of Australia. Sheep have died after consuming large quantities from lush stands. Ingestion has also led to urinary calculi problems in sheep (Cunningham et al. 1981). There is no danger of poisoning in humans provided that New Zealand spinach is eaten in moderate amounts. Curiosity

New Zealand spinach was introduced to Europe in 1770 by the famous British naturalist Sir Joseph Banks (1743–1820) and grown in 1772 at the world’s premier botanical garden, Kew Gardens in London; ironically it has never become popular in British gardens.

Problems and potential New Zealand spinach is likely to remain a minor crop in Canada, because its competitor, the familiar spinach, is well established. Some commercial use is possible to supplement the domestic spinach crop during the growing season.

Selected reference Tindall 1983.

Tragopogon Salsify Compositae (Asteraceae) Composite family Composées, famille de la marguerite

Genus notes Tragopogon consists of 50 biennial or perennial herbaceous species with long taproots. They are native to Europe, northern Africa, and parts of Asia (Bailey and Bailey 1976). The one cultivated species is discussed below.

Names Scientific (Latin) name: Tragopogon porrifolius L. English common name: salsify Also: oyster plant, oyster-plant, purple goat’s beard, vegetable-oyster, vegetable oyster French common name: salsifis (m) Also: salsifis blanc, salsifis des prés

Description and taxonomy The cultivated phase of this species is subsp. porrifolius. It perhaps originated in the central and eastern Mediterranean region. It is differentiated from the wild forms by inconspicuous floral characters. In Canada, T. porrifolius, introduced from the Old World or escaped from gardens, is naturalized along roadsides and in fields in most Canadian provinces (Scoggan 1978–1979). The wild Old World forms are placed in the following two subspecies, both found in Europe (Tutin et al. 1976; Schultze-Motel 1986): subsp. australis (Jordan) Nyman has slightly hairy leaves and is native to the Mediterranean region, extending northwards to Romania subsp. cupani (Guss. ex DC.) I.B.K. Richardson has quite hairy leaves and is found in southern Italy and on the island of Sicily Salsify was known to the ancient Greeks and Romans, who gathered it from the wild. The plant was cultivated in France and Germany by the 15th century, although it may have been eaten in these countries earlier. The English quickly adopted it both as a

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vegetable and as a flowering ornamental. In the 17th century salsify was brought to America, where it was valued for its “tonic” properties as a diuretic (Halpin 1978).

Uses The long, white-skinned taproots and occasionally the leaves are consumed as a vegetable. The roots are cooked as a separate vegetable and are also employed as an ingredient of soups and other dishes. Example recipes

Baked salsify (Grieve 1978) Chicken braised with salsify (Schneider 1986) Cream of salsify soup (Morash 1982) Salsifis à blanc (Szczawinski and Turner 1978) Salsify cream soup (Grieve 1978) Salsify pie (Organ 1960) Salsify poulette (Morash 1982) Salsify with cheese (Grieve 1978) Sautéed salsify (Szczawinski and Turner 1978) Sautéed-braised salsify (Morash 1982) Stewed salsify (Grieve 1978) Veal and salsify ragout (Morash 1982)

Importance Salsify is mainly cultivated in Europe and western Asia. In 1987, the combined European production of salsify and the rather similar scorzonera (Scorzonera hispanica L.) was 69 000 t from 3800 ha (Hinton 1991). Only a little salsify is grown in the United States. No statistics seem available for salsify production in Canada, although it has been marketed in Toronto (Anonymous 1989).


Salsify has a long tap root that develops best in rich, loose, sandy loam or loam soils. The soil pH should be at, or slightly above, 7.0 (Halpin 1978). Tests in France have shown that very sandy soils do not produce good roots. Deep cultivation is also important, and the soils in France are worked to a depth of 30 cm (Jourdan 1984).

Climate

Salsify is a hardy biennial that can overwinter by its roots, regrowing leaves and a flowering stalk in the second year. Irrigation is beneficial during dry periods. Adequate soil moisture is most important at two stages: during the elongation of the roots shortly after germination, and as the roots thicken in late summer and autumn (Jourdan 1984).

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Propagation is by seeds. These should be sown in mid spring to provide a long growing season, because about 4 months are required to produce roots of harvestable size. In the warmest parts of Canada, the seeds could be planted in June as the plants will continue to grow into late October (Halpin 1978). The crop is produced as an annual.

Harvest and storage

The oyster flavor that gives the roots their distinctive taste is enhanced by light frosts. The roots can be harvested during autumn or left in the ground overwinter under a mulch for an early spring crop. The roots taste best if consumed shortly after harvest. However, they can be stored for long periods if placed in moist sandy soil in a cool place. The oyster flavor decreases with prolonged storage (Halpin 1978).

Example cultivar

Mammoth Sandwich Island. The Research and Plant Breeding Institute for Vegetables in Olomouc, Czechoslovakia, conserves salsify germplasm (Bettencourt and Konopka 1990).


Salsify is a corruption of the old latin name solsequium. This was derived from the Latin words sol (sun) and sequens (following), meaning the flower that followed the course of the sun (Grieve 1978).

Problems and potential Salsify is likely to remain an occasional crop of home gardens and perhaps local markets in Canada. Its nature and potential are similar to that of scorzonera, also treated in this book.

Selected references Grieve 1978; Halpin 1978; Jourdan 1984.

Valerianella Corn salad Valerianaceae Valerian family Valérianacées, famille de la valériane

Genus notes The genus Valerianella has about 80 annual herbaceous species distributed in temperate parts of the Northern Hemisphere (Clapham et al. 1987). In addition to V. locusta, discussed below, V. eriocarpa Desv., hairy-fruited corn salad or Italian corn salad, is also employed as a potherb and salad plant (Bailey and Bailey 1976). This native of southern Europe and north Africa is cultivated in the Mediterranean region, but not in North America to any appreciable extent.

Names Scientific (Latin) names: Valerianella locusta (L.) Laterrade English common name: corn salad, mâche (pronounced mash) Also: corn-salad, field salad, common corn salad, lamb’s lettuce, field lettuce French common name: mâche commune (f) Also: mâche, doucette, valérianelle

Description and taxonomy Corn salad is a small annual herb, which is native to the Mediterranean area. It has been valued by Europeans as a delicacy since early Roman times. Cultivars have been selected, based on leaf characters and flavor. Heij (1989) noted that two classes of cultivars are recognized in Europe, as follows: North Holland, referred to as var. oleracea (Schlecht.) Breistr. by some authors (Tutin et al. 1976), has long, pale green leaves and is favored in Holland. This long-leaf variety is called “blond” or “green” corn salad or mâche (Richardson 1990). Vit, called var. locusta by some authors (Tutin et al. 1976), has short, dark green leaves and is preferred in many parts of Europe. This short-leaf variety is known as “shell” corn salad or mâche, and is darker, firmer, and stronger-tasting (Richardson 1990). A taxonomic distinction between wild and domesticated plants has not been made. Valerianella locusta is considered to be native to

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Europe, western Asia, and northern Africa (Clapham et al.1987). In North America, corn salad has become naturalized in old fields, waste places, and along roadsides. In Canada, it has been found growing wild in southwestern British Columbia and southern Ontario (Scoggan 1978–1979).

Uses The dark green leaves of corn salad are tender and have a tangy, sweet, nutlike flavor. This vegetable is usually consumed fresh in salads. It can also be cooked quickly and served like spinach. In Europe, corn salad is often included in dishes containing beets (Halpin 1978). Example recipes

Corn salad (Buishand et al. 1986) Corn salad with omelette (Buishand et al. 1986) Fancy mâche salad (Richardson 1990) Mâche (corn salad), bibb lettuce, and mushrooms with cream dressing (Schneider 1986)

Importance Corn salad is grown as a commercial crop in Europe. Heij (1989) reported that 40 ha of corn salad were grown under glass in Holland. Other major production areas are France and Switzerland. Medsger (1974) noted that corn salad is sold in New York markets under the names “field salad,” “fetticus,” and “pawnee.” According to Richardson (1990) production in Canada and the United States is increasing.


Corn salad grows naturally on a variety of soils in its native distribution, ranging from arable land to dunes, usually on dry soils (Clapham et al. 1987). It performs best on soils enriched with organic matter high in nitrogen (Halpin 1978). It grows well hydroponically.

Climate

Corn salad prefers cool weather for germination and growth. In Canada, it should be sown outdoors as soon as the earth can be worked. Staggered sowings are possible, although plants may bolt in hot summer weather. Corn salad can also be sown in cool autumn weather and covered with a light mulch, so that seeds will germinate in the early spring. Water is beneficial during dry periods (Halpin 1978). Greenhouse corn salad prefers cool temperatures (5°C at night and 10°C during the day). Although corn salad will tolerate warmer temperatures, ventilation is recommended above 12°C (Heij 1989).

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Propagation is by seeds, which are directly sown outdoors. The seeds are tiny, and plants should be thinned (Halpin 1978). Light cultivation may be needed to prevent competition from weeds. In commercial greenhouses in Europe, corn salad is sown directly in greenhouse earth or germinated in artificial soil blocks. The second method has resulted in superior germination, shorter time to harvest, and a cleaner crop. Experiments using European varieties have shown that a planting density per square metre of 55 plants was optimum.

Harvest and storage

Corn salad leaves are hand-harvested when individual leaves are several centimetres long, or the entire shoot can be harvested when it matures (before flowering). Some growers prefer to blanch the leaves by placing a lightproof container or soil around the base of the plant (Halpin 1978). Many growers prefer to pick and market corn salad with the roots still attached. Leaves should be eaten fresh or stored in a refrigerator as quickly as possible. Commercially, rinsing with water provides a fresher and cleaner product. Plants should be rapidly cooled and can be stored at 12°C for 4–8 days (Heij 1989). Corn salad should be washed and drained completely of any excess moisture before being stored airtight in a plastic bag.

Example cultivars

Broadleaf Dutch, Verte de Cambrai. Some Canadian garden catalogs sell corn salad seed under the common name “lamb’s lettuce.” Facciola (1990) provided an extensive description of corn salad cultivars available in the United States.


Although it is often found growing wild as a weed in American cornfields, corn salad has nothing to do with corn; it is used in salads.

Problems and potential Corn salad is likely to remain a minor crop in Canada, appealing mainly to recent immigrants from parts of Europe where the vegetable is commonly sold. It is grown commercially in Europe, where significant amounts are produced in greenhouses (Heij 1989). Because of its popularity in Europe, it is possible that the crop could become more widely grown in Canada for use in specialty salads. There is potential for growth of corn salad in greenhouses during the winter months. Corn salad is considered a “gourmet” green and is hard to find; therefore, it is a high value crop. Unfortunately it does not keep well and should be used within a day or two of purchase.

Selected references Halpin 1978; Heij 1989; Richardson 1990.

Vicia Faba bean Leguminosae (Fabaceae) Pea family Légumineuses, famille du pois

Genus notes The genus Vicia consists of about 150 species of annual and perennial herbs, distributed through temperate regions of the world (Bailey and Bailey 1976). Several species are important for forage or as a cover crop. Vicia faba is used as human food, as discussed below. Species important as forage include V. dasycarpa Ten., woolly-pod vetch, native to Europe; V. pannonica Crantz., Hungarian vetch, from central Europe; V. sativa L., common vetch, native to Europe; and V. villosa Roth., hairy vetch, native to Eurasia.

Names Scientific (Latin) name: Vicia faba L. English common name: faba bean Also: broad bean, fava bean, horse bean, English bean, European bean, Windsor bean, tick bean, tick pea, pigeon pea [The species is known in Europe as field bean and sometimes common bean; see “Description and taxonomy”] French common name: gourgane (f) Also: fève des marais, féverole [féverole = field bean, horse bean]

Description and taxonomy Faba bean is an annual herbaceous plant that originated in the Near East and is now cultivated in temperate parts of the world. No wild forms are known. Classification of faba bean is based on the size of seeds and pods and large-, medium-, and small-seeded forms are recognized as formal categories; however, these groupings seem to have an artificial rather than genetic basis. (See distinction of artificial and natural classification in “Plant classification and

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plant names”.) Vicia faba is now often termed “faba bean,” a name said to have originated in Canada (Hawtin and Hebblethwaite 1983), although “fava bean” has been used for centuries. The principal categories, each of which has its own common names, are as follows (after Bond et al. 1985; Schultze-Motel 1986): small-seeded form subsp. minor (Peterm. ex Harz) Rothm.(= V. faba subsp. eu-faba Murat. var. minor Peterm.), pigeon pea, tickpea, having seeds less than 15 mm long subsp. faba, which is divided into two varieties: – medium-seeded form var. equina Pers. [ = V. faba subsp. equina (Pers.) Schubl. et Mart.], horsebean, having seeds 15–19 mm long; – large-seeded form var. faba (= V. faba var. major Harz. of some authors), broad bean, Windsor bean, having seeds more than 20 mm long. The small-seeded form is considered the most primitive of the groups recognized (Cubero 1974). The large-seeded form is most commonly used for human food and is the kind generally referred to in the following treatment. Outside North America, the name “broad bean” almost exclusively denotes V. faba used for human food. In the following discussion the names broad bean and faba bean are used interchangeably. In Europe, the minor and equina groups are generally called field bean, or sometimes common bean. However, in North America, the terms “field bean” and “common bean” are predominantly used for Phaseolus vulgaris, including the green, yellow, and pole beans familiar to home gardeners. Evidence suggests that faba bean originated in the Near East, with selections radiating outwards geographically. Secondary centres of diversity may have occurred in Ethiopia and Afghanistan (Cubero 1974). Evidence of faba bean usage has been found at Iron Age sites in Europe, and there are also findings of seeds from around 1800 B.C. in ancient Egypt. There is no evidence of faba bean use in China until A.D. 1200. In China, almost all the faba beans are the large-seeded form, which was not known to have existed elsewhere until about A.D. 500. Faba bean was carried to Mexico and South America by Spanish explorers (Simmonds 1976; Hawtin and Hebblethwaite 1983).

Uses The seeds of the broad bean are the size of lima beans. They have been used like limas in those parts of western Europe and North America that have soil too chilly to germinate limas and a growing season too short or too sunless to mature either pole beans or limas. The seeds of broad bean have a strong, gamy flavor, not as sweet as limas. The nutritional value of faba bean is considerable, and it has been called “poor man’s meat.” As a source of protein it is deficient in

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sulfur-containing amino acids but is high in lysine. Both whole pods and shelled seeds of faba bean can be used for human food. Faba bean can be harvested at an immature stage, and the whole pods cooked. When young and tender, they can be eaten raw in salads. As the pod ages, the seeds should be shelled and, because some people find the mature skins difficult to chew, may even need to be skinned before cooking. The immature pods are canned and frozen in northwest Europe, where problems of mechanized harvesting limit the crop. The ripe seeds are used in stews and soups and may be deep-fried, ground for meal, or boiled. The beans can be dried for storage. Mature beans can be sprouted by soaking them in water, and allowing the seeds to germinate. The sprouts may be added to soups (Simpson 1983). In Latin America, seeds are roasted and used like peanuts, even though they are much harder to chew than the latter. Recently there has been interest in developing protein concentrates from faba bean, for use in the manufacture of textured protein to replace meat. Faba bean is also widely used as feed for livestock—either as meal, seed, or whole plant roughages such as silage and forage. It has been evaluated and used in Canada for beef and dairy cattle, poultry, sheep, and swine (Platford et al. 1983; Drapeau 1991). Indeed, the main use of faba bean in Canada has been as a protein supplement produced by farmers to feed their livestock. Raw, unprocessed beans produced for the purpose are generally coarse-ground or hammer-milled and mixed directly into rations for all types of stock. Faba beans are considered highly nutritious in energy value and digestibility, as well as in protein content. Example recipes

Broad beans with mint (Buishand et al. 1986) Broad beans with red pepper (Buishand et al. 1986) Fava beans in garlic cream (Levy 1987) Fava risotto with fresh sage (Schneider 1986) Shrimp and fava with thyme (Schneider 1986) Stewed fava beans and leeks with lemon (Schneider 1986)

Importance Vicia faba is extensively cultivated as a legume grain in the north temperate zone and, at higher altitudes during the cool season, in some subtropical regions. Occasionally it is used in mixtures with other crops for silage and green manure. In Canada, faba bean for livestock is a new but promising crop; already faba bean for soup is popular in the Lac-Saint-Jean and Saguenay regions of Quebec, and the large-seeded broad bean is occasionally cultivated in home gardens. Although faba bean crops have achieved their best growth in southern Ontario, they are grown more widely in western Canada than in the East. Large-scale faba bean production in western Canada started only in 1972, but since then this crop has become increasingly important as a source of protein for animal feed, with yields exceeding 2200 kg/ha.

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In Canada, faba bean is grown mostly for animal feed, with some exported for human food. The small- and medium-seeded forms are cultivated, mostly in the Prairie Provinces. The crop has also been used for silage; in some years, faba silage has been grown on as many as 5000 ha in Alberta (Hawtin and Hebblethwaite 1983). The Canadian Seed Growers’ Association noted that 347 ha of faba bean were grown in 1991 for various grades of seed (Anonymous 1992e). Few statistics seem available on human use of faba bean in Canada. About 90 t of faba bean are grown in the Lac-Saint-Jean region of Quebec to supply what are called locally “gourgane” beans for canning and soup.


Faba bean tolerates many soil types but performs best on rich loams. It is well adapted to the wetter portions of the Canadian prairies. It is more tolerant of acid soils than most legumes and grows best with the pH in the range of 4.5–8.3 (Duke 1981).

Climate

Faba bean requires a cool season for best development. The optimum growing temperatures are 15–18°C, with maximum temperature of 24°C and mimumum of 4°C. It can tolerate late spring frosts but is not drought resistant and requires irrigation during dry periods (Nonnecke 1989).


Propagation is by seeds. Faba bean is frost tolerant during the seedling stage and should be sown as soon as soil conditions permit. In fact, late planting (e.g., after May 15 in the Prairies) increases the risk of frost damage in the fall before harvest time. In commercial operations, the soil is plowed to a shallow depth. Large-seeded forms are sown using planters (drills) for lima beans, and small-seeded forms using corn planters. It is beneficial to add to the seeds a bacterial inoculum recommended for faba bean. Faba bean is a poor competitor, so weed control is particularly important. If chemical control is not used, the plants require occasional harrowing for weed control (Duke 1981; Platford et al. 1983; Nonnecke 1989).

Harvest and storage

Mechanical harvesting has not been developed sufficiently for harvesting immature green pods, although mobile pea-vine pickers are used. Losses tend to be higher than for peas (Pisum sativum) but can be reduced if plants are swathed 12–24 h before picking. The pods must be processed within 1 h of harvest to prevent discoloration; alternatively, staining may be delayed by covering the beans with ice or chilled water (Hebblethwaite et al. 1983; Nonnecke 1989).

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Immature pods are gathered when they are 5–7 cm long, before a hairy bloom develops on the interior. The seeds can be shelled from the pods and used like peas (Halpin 1978). For seeds to be used for human food or animal feed, faba beans are harvested with combines adapted for common beans. As faba beans mature, the lower leaves darken and drop, and the pods turn black and dry progressively up the stem. Faba beans shatter if left to stand until maturity. Therefore, they are swathed (cut) when the lowest two pods begin to blacken. Shattering losses during harvest are a major problem when combining. It is important to match closely the pickup speed to the ground speed. Combining is more effective in early morning when the moisture content of the plants is higher. For use as silage, faba beans are swathed and left to wilt for 2–3 days (Platford et al. 1983; Ellis et al. 1988). In commercial operations, faba beans are dried, at a maximum temperature of 30–40°C, to achieve as low as 16% moisture, depending on the seed grade. If more than 5% moisture needs to be removed, drying takes place in two stages. Natural air drying is commonly used (Platford et al. 1983). Example cultivars

Small-seeded: Broad Windsor Small Pod Bush. Large-seeded: Con Amor, Conqueror, Early Improved Long-pod, Long Pod Fava, Toto. Faba beans are often listed under “broad beans,” “Windsor beans,” or “English broad/Windor beans” in Canadian garden catalogs. Malo and Bourque (1992) discussed recent trials of faba bean cultivars in Montreal. Faba bean genetic resources were discussed by Summerfield (1988). Facciola (1990) provided an extensive description of faba bean cultivars available in the United States. Methods and objectives for faba bean breeding were discussed by Lawes et al. (1983).

Additional notes Faba beans contain antinutritional constituents that can cause significant problems in some people. They have hemagglutinins and a low level of trypsin inhibitor. Long-term ingestion of hemagglutinin can seriously impair intestinal absorption and of trypsin inhibitor may increase the requirement for vitamin B12. The presence of oligosaccharides (raffinose and stachiose) leads to flatulence. The most serious effects result from the presence of β-glycosides (vicine and covicine), which lead to a hemolytic syndrome in some individuals. The condition, known as “favism,” is characterized by weakness, pallor, jaundice, and hemoglobinuria (blood in urine). Death can result from renal failure. This syndrome occurs in individuals who are deficient in glucose-6-phosphate dehydrogenase (G6PD), but it may not be the only deficiency associated with favism (Simpson 1983). In those susceptible to favism the G6PD activity is only 0–6% of normal. Certain racial or ethnic groups, including Oriental Jews, Mediterranean Europeans, Arabs, Asians, and Blacks,

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have higher incidence of favism than other groups. In cases of extreme sensitivity, even the pollen induces an attack. Favism does not occur in people without the genetic predisposition (Cheeke and Shull 1985). Curiosities

Many ancient cultures seem to have developed a love–hate relationship with the broad bean. On the negative side, several students of the Greek philosopher and mathematician Pythagoras (who died ca. 497 B.C.) are said to have allowed themselves to be slaughtered by soldiers rather than escape through a field of beans. Pythagoras himself is thought to have refused to enter a bean field while attempting to escape from pursuing Crotons, which led to his capture and execution. Upper-class Greeks and Romans regarded the bean as harmful and thought that eating it would cloud their vision. It is possible that this aversion to broad beans traces to the harmful effects of favism, because about 1% of people of Greek and Italian descent are susceptible to this condition. By contrast, the broad bean was respected by others. The Fabii, one of the noble families of Rome, derived their name from the broad bean. During the Roman feast of Fabaria, beans were offered symbolically, and some Romans even believed that after death one’s soul took up residence in a bean. Many species of Vicia, including the broad bean, possess nectaries on the stipules (bracts at the base of the leaves). In most plants, nectaries are only found in flowers, where they attract pollinators. Ants have often been noted collecting nectar from the leaf nectaries of the broad bean. It is believed that these ants have established a symbiotic association with the broad bean, the ants protecting the plants against caterpillars while obtaining nourishment from the nectar.

Problems and potential Faba beans are susceptible to several disease and insect pathogens. The producer needs to avoid growing faba bean in the same field in consecutive years as oilseed and other legume crops, which share many of the same diseases. A 5-year crop rotation is recommended, avoiding other legumes, to reduce pathogen buildup (Platford et al. 1983; Anonymous 1984b; Martens et al. 1984). Other problems involve susceptibility to hot, dry spells, because faba bean is adapted to cool, moist conditions. Faba bean has a number of desirable agronomic characteristics that make it a plant of particular interest in Canadian agriculture. It fits well into the basic cereal crop rotation followed on many farms. On the Prairies, faba beans have given good yields both on summerfallow and on well-prepared stubble land. Existing farm machinery can generally be used. In suitable varieties, the pods do not shatter easily and can be combined. The faba bean has a high degree of frost resistance, especially in the spring, when it is possible to sow seed into frozen ground. The plant is mainly self-fertile, and hence not

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particularly dependent on pollinators. The protein is of good quality. Little nitrogen fertilizer is needed because of the nitrogen-fixing nodules present, although inoculation with suitable bacteria is usually advised. Where faba beans are not sufficiently early in maturity for consistent seed production, they can often be used to produce a high-quality forage. Faba bean is a minor crop in Canada, grown mainly for use as animal feed. Given its desirable properties, noted above, the use of faba bean as human food deserves increased attention. It is used locally in Quebec as an ingredient in soup and is familiar to Canadians of European and Middle Eastern origin. There is potential for increased production for use both in Canada and as an export. Faba beans are being processed for use as protein supplements and substitutes, and there is potential for increased application in these respects.

Selected references Hebblethwaite 1983; Lawes et al. 1983; Bond et al. 1985; Summerfield 1988.

Vigna Leguminosae (Fabaceae) Pea family Légumineuses, famille du pois

Genus notes The genus Vigna contains more than 200 species of erect or twining herbaceous annuals native to warm regions of both the Old and New worlds. This genus is closely related to Phaseolus, which includes common bean, lima bean, and scarlet runner bean (Bailey and Bailey 1976). Indeed, many cultivated members of Vigna were once included in Phaseolus. However, Baudoin and Maréchal (1988) delimited Phaseolus as a genus restricted to the New World, while recognizing Vigna as a genus widely distributed in the tropics of both the New and Old worlds. Vigna includes several cultivated species grown for food and forage, green manure, and cover crops (Duke 1981), as noted below. Vigna aconitifolia (Jacq.) Maréchal, known as moth bean or mat bean, grows wild from India to Burma. Its cultivation has spread to China, Africa, and the southern United States. The pods and ripe seeds are used for human food and it is also grown as a green manure, cover crop, and for erosion control. Twenty introduction lines of moth bean were evaluated at Agriculture and Agri-Food Canada’s Research Station at Delhi, Ontario, with yields ranging from 237 to 921 kg/ha. Vigna angularis (Willd.) Ohwi & Ohashi, adzuki or adsuki bean, is probably native to India or Japan. It has long been established in China and Sarawak and has been cultivated for centuries in eastern Asia. It was introduced for cultivation in warm parts of the Americas and in some African and Pacific countries. It is used as human food and is considered to have medicinal properties in China. Adzuki beans have been grown experimentally in Manitoba and British Columbia. Vigna mungo (L.) Hepper, black gram or urd, is not known in the wild state. It was cultivated in ancient India and is now grown in the southern United States, the West Indies, and other tropical areas. However, it is extensively used only in India. Black gram is used for human food, green manure, a cover crop, and as forage. The use of the term mungo in the scientific name V. mungo has caused considerable confusion with “mung bean,” the species, V. radiata, especially as the two species are closely related and rather similar. Vigna umbellata (Thunb.) Ohwi & Ohashi, rice bean or Mambi bean, is native to the Himalayas and central China to Malaysia. It is cultivated in eastern Asia, Africa, the West Indies, Australia, and the United States. It is used as human food, green manure, a cover crop, and forage.

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Vigna unguiculata (L.) Walp. originated in tropical Africa where a wild form still occurs. There are several different cultivated subspecies, one of which is discussed below. The various subspecies are employed for human food, green manure, cover crops, and forage.

Mung bean

Names Scientific (Latin) name: Vigna radiata (L.) R. Wilczek Frequent scientific synonym: Phaseolus aureus Roxb. English common name: mung bean Also: bean sprouts, green gram, golden gram French common name: haricot mungo (m) [The French “haricot mungo” also designates V. mungo; mung bean sprouts = germes de haricot (m), or more precisely germes de haricot mungo.]

Description and taxonomy Mung bean is a bushy, herbaceous annual plant native to India and east Africa. The cultivated form, var. radiata, is grown as human food and animal forage and is also used as green manure and a cover crop. The wild forms of mung bean (Baudoin and Maréchal 1988) include var. sublobata (Roxb.) Verdc., in east Africa, Madagascar, India, Sri Lanka, southeast Asia, and north Australia var. setulosa (Dalz.) Ohwi & Ohashi, in the eastern parts of tropical Asia from India to Indonesia and southern China. India is often considered to be the most likely region of domestication. Mung bean was cultivated in India for several thousand years, and its use spread westward. Western Asia (Afghanistan, Iran, and Iraq) has the most genetic diversity (Tomooka et al. 1992). In recent times, mung bean has been introduced into the West Indies and the United States. It is difficult to establish when the practice of using mung beans for germinated sprouts began. It has been said that germinated mung beans are the oldest of culinary sprouts and have been used for food by the Chinese for nearly 5000 years (Larimore 1975). However, the ancient use of mung beans for sprouts in either India or China has not been proven. A variety of legumes were occasionally used as sprouts during past millenia in Asia, including faba bean (Vicia faba), pea (Pisum sativum), and species of Phaseolus; it may well be that mung bean was also used.

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Uses Mung bean is now the most popular of sprouts. As a vegetable in Canada, mung bean is most familiarly used as freshly sprouted seeds. In Asia, mung beans are commonly sprouted, but the whole seeds are also cooked. In several thirdworld countries mung bean is more extensively used for animal feed and for its seeds. Mung beans can be boiled or fried and eaten whole, parched and ground into flour, or eaten green as a vegetable. The sprouts are sometimes used in soup or with sugar as a snack or dessert. Outside Canada the crop is also raised for fodder, hay, Mung bean sprouts green manure, and as a cover. The mung bean is widely regarded as nonflatulent and easily digested, and cooked mung beans are a good food for small children, invalids, and elderly persons (Singh and Singh 1992). However, antinutritional factors are reported to be present in the seeds. Germinating seeds to produce sprouts not only reduces these antinutritional factors but also improves nutritional content of various constituents (Singh and Singh 1992). Extracts of mung bean are important for preparing various foods (Singh and Singh 1992). Mung beans are used in making some noodles; the starch is reported as the best raw material for making transparent starch noodles. Example recipes

Dhal (spread for bread and rice dishes) (Tudge 1980) Omelette for one (Blanchard 1975) Spanish rice (with mung bean sprouts) (Blanchard 1975)

Importance Mung bean is an important crop in Asia, where annual production often exceeds 1 000 000 t. India is the largest producer and consumer, the crop grown mainly to produce dried seeds for human consumption (Lawn and Ahn 1985). Data on world production of bean sprouts seem unavailable. In the United States, more than 50 000 ha of mungbean are planted annually, of which more than half are plowed under as a green manure. Less than 25 000 ha are harvested for seed production. About 10 000 t of mung bean sprouts are consumed in the United States each year (Cupka and Edwards 1988). About 1200 t of sprouts are consumed in Canada annually (Nonnecke 1989). Bean sprouts are commonly sold in supermarkets, specialty food stores, and salad bars and are an important component of Oriental restaurant meals. Demand for this product has been increasing (Anonymous 1989).

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Field-grown mung beans are adapted to a variety of soils but grow best on well-drained loams high in organic matter. The pH should be 6.0–7.0. Mung beans perform poorly in heavy soils with poor drainage (Duke 1981, Cupka and Edwards 1988).

Climate

Mung bean is a tropical plant requiring warm conditions. Temperatures of 25°C or more are needed for good germination and seedling development. Mung bean tolerates heat up to 36°C and develops well when mean daily temperatures are above 20–22°C; the optimum is 28–30°C. Irrigation is beneficial during dry periods for field-grown plants (Duke 1981; Lawn and Ahn 1985).


Propagation is by seeds. In commercial operations, mung beans grown as field plants are direct-seeded in a well-prepared seed bed. A shallow cultivation is beneficial to reduce weeds before the plants grow taller than 5 cm (Cupka and Edwards 1988). For sprouts, mung bean seeds are soaked for about 12 h in water and then drained and placed in lightproof bean-sprouting chambers with temperatures above 25°C. For home use, the bean-sprouting chamber can be as simple as a wide-mouth jar or clay pot covered with cheesecloth or plastic screening. The sprouts are rinsed and drained every few hours and are ready for harvest within a week (Harrington 1978). One kilogram of dry mung beans produces 6–9 kg of sprouts. Sprouting seeds are selected for a good ratio of sprout weight to seed weight, such as 9 g of sprouts produced by 1 g of seeds. Seeds should also produce sprouts with thick, long hypocotyls (region of seedlings between true root and true stem) that are longer than 5 cm and thicker than 2 mm. The roots must be short and the sprouts as white as possible (Cupka and Edwards 1988).

Harvest and storage

Commercial field-grown mung beans are mechanically harvested and threshed after the seeds are mature. The preferred method consists of threshing the mung bean seeds directly from the live plants using a conventional combine. All foreign matter, including leaves, stems, and immature pods, must be removed by screening the seeds, to prevent growth of fungi or bacteria. Seeds are then stored in large steel or concrete bins, which may be fumigated at storage time to control various bean weevils (Cupka and Edwards 1988). For home use, edible pods should be picked when the seeds have barely become evident externally on the pod (Harrington 1978). Mung bean sprouts are ready for harvest in 4–6 days. Sprouts are rinsed in cool water and any loose hulls or unsprouted seeds are removed. The sprouts can be stored in cool temperatures (just above freezing) with high humidity. They are best used fresh. For home storage, the sprouts can be placed in a jar with cold water in a refrigerator for about 1 week, with daily changes of the water (Harrington 1978).

Example cultivars

Berkins Jumbo, Look Dow.

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More than 100 cultivars are grown in Asia. In the United States, the main cultivars are Golden and Green, both raised for hay and green manure, and the latter also raised for dry beans. Other cultivars produced in North America include Lincoln and Morden. The cultivar AC Harrow Sprout was recently released by the Agriculture and Agri-Food Canada research station at Harrow, Ontario (Greenhouse and Processing Crops Research Centre) (Hill 1996). Cultivars with hard, shining dark green seed coats are preferred for bean sprouts. Mung beans are occasionally found in Canadian garden catalogs listed simply as “mung beans.” The most common source of mung bean seeds for home sprouting are health food stores, especially food stores that provide bulk seeds and grains. Sources of mung bean germplasm were discussed by McLean (1988).


The word mung originates from the Tamil mungu and the Sanskrit mudga, ancients names for the mungbean.

Problems and potential Mung bean seeds can be infested with seed-boring insects that pupate and mature within the seeds. The sprouts are susceptible to fungal and bacterial pathogens (Cupka and Edwards 1988). Mung beans have been grown experimentally at the Morden Research Station, Manitoba, but commercial crops may be unlikely in Canada because of the requirements of warm temperatures and a long growing season. Although mung beans have not been grown commercially in Canada, they could be, for example in Ontario in the warm climate and long growing season of Essex County or the Lake Erie shores in Kent and Elgin counties (Hill 1996). Seed is available for the commercial sprouting industry, and sprouts are provided to supermarkets and other food outlets across Canada. There has been an increase in demand as consumers become familiar with the use of sprouts as a vegetable. The seeds are also sold for home-sprouting.

Selected references Duke 1981; Lawn and Ahn 1985; McLean 1988.

Yard-long bean Vigna unguiculata is a herbaceous annual which includes erect and twining forms. A wild form of the species, subsp. dekindtiana (Harms)

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Verdc., is native to tropical Africa (Schultze-Motel 1986). The species has been cultivated since ancient times. Several cultivated subspecies are recognized (Duke 1981; Schultze-Motel 1986), as noted below. Subspecies cylindrica (L.) Verdc., catjang bean or sowpea, is native to India and Sri Lanka. It is raised in tropical regions of eastern Africa and Asia where it is employed as human and animal food as well as green manure. Subspecies unguiculata, cowpea or black-eyed pea, has been used since ancient times in Africa and Asia. Essentially wild forms are still grown in Ethiopia. The centre of domestication of cowpea was in west-central or south-central Africa, in the region of Nigeria to Zaire (Anonymous 1992c). It is now widely cultivated and is used for human and animal food and as green manure, hay, or silage. Cowpeas are sensitive to cold and are killed by frost. The crop is adapted to warmer climates than available in most of Canada, although early maturing cultivars can produce pods in 50 days and seeds in 90 days. Some types of cowpeas, including black-eyed peas, may be grown as a garden curiosity in the warmest parts of Canada. Subspecies sesquipedalis is discussed below.

Names Scientific (Latin) names: Vigna unguiculata (L.) Walp. subsp. sesquipedalis (L.) Verdc. Frequent scientific synonym: Vigna sesquipedalis (L.) Fruhw. English common name: yard-long bean Also: asparagus bean, Chinese long bean, dow guak (dau gok, dow gok) French common name: dolique asperge (m) Also: haricot vert chinois

Description and taxonomy Yard-long bean is a strong, climbing, annual vine that produces pods 45–90 cm long. Bush cultivars are being developed in the Philippines. The crop is cultivated mainly in the Far East (Bangladesh, India, Indonesia, Pakistan, and Philippines). This vegetable is also grown in the Caribbean, Africa, and parts of Europe (Duke 1981). More recently it has found its way to North America where it is now available through garden catalogs. To a limited extent, yard-long bean is cultivated in the United States for the local market (Richardson 1990).

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Yard-long bean originated either in India or Africa, but a wild form of this subspecies is unknown (Schultze-Motel 1986). The centre of diversity of subsp. sesquipedalis is thought to be ancient India. It was selected from subsp. unguiculata, which arrived in India from Africa as early as 1500 B.C. (Simmonds 1976).

Uses Yard-long beans are cut into short lengths (4–6 cm) and stir-fried, boiled, or steamed. The flavor is more pealike and less juicy than common beans. Some people find the taste reminscent of asparagus. The young leaves and stem are also used as a green vegetable (Halpin 1978). The plant is used additionally as animal feed. Example recipes

Longbeans with Chinese BBQ pork (Richardson 1990) Stir-fried yard-long beans with beef and mushrooms (Schneider 1986) Sweet-sour yard-long beans with peanuts (Schneider 1986) Yard-long bean, eggplant, and tomato stew with mint and dill (Schneider 1986) Yard-long beans with pork (Schneider 1986)

Importance Yard-long beans are an important vegetable in southeastern Asia, particularly with Chinese market gardeners. In the Phillippines, yields of yard-long bean pods average 4–5 t/ha with maximums of 10 t/ha (Duke 1981). No statistics for production of yard-long bean seem available in Canada, where this vegetable is just a curiosity of home gardens.


Yard-long bean grows on many soil types, including sandy loams and clay. The recommended pH is 5.5–6.0 (Duke 1981).

Climate

Yard-long bean is a plant of the warm tropics and performs best when mean daily temperature is 20–30°C. It is killed by frost and cannot tolerate temperatures below 4°C for long. Soil temperatures should be above 21°C for successful germination (Tindall 1983). The plants are sensitive to waterlogging but require a steady supply of soil moisture for proper growth (Duke 1981).


Propagation is by seed. This tropical plant requires 2–3 warm months to produce pods and is best started indoors and transplanted outdoors. Seeds can be sown outdoors in the warmest regions of Canada, after all danger of frost is past and the soil has warmed. Seeds do best when planted in hills that promote warmer soil conditions. The plant is a vine that grows 2–3 m tall under ideal conditions. It is usually grown on a trellis or poles formed into a tripod so that the pods can develop long and straight (Duke 1981). Inoculation with the cowpea rhizobium, Bradyrhizobium, is recommended in substrates that have not previously grown this crop (Meyer 1992).

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Harvest and storage

The pods are hand-harvested when immature (about 30–45 cm long under ideal conditions), before the seeds fill out the pods. Although impressively large, mature pods are tough and stringy, and useless as a vegetable. However, the mature seeds can be harvested as the pods dry. The young pods should be used fresh (Halpin 1978; Harrington 1978; Duke 1981).

Example cultivars

This plant is sold in Canadian garden catalogs under several names including “Yard Long,” “Asparagus Bean,” “Spaghetti Pole,” and the Chinese name “Dow Guak.”


An oriental healing recipe entitled “Yard-long Bean and Pig’s Pancreas Soup” is used to treat dropsy (edema).

Problems and potential Yard-long bean will probably remain a novelty of home gardens. It has little potential as a crop because it is adapted to a typically warmer climate than in most of Canada. There may be some potential for its sale in local markets to Canadians whose ethnic traditions have resulted in familiarity with the vegetable.

Selected references Halpin 1978; Harrington 1978; Duke 1981; Meyer 1992; Singh and Singh 1992.

Zea Sweet corn Gramineae (Poaceae) Grass family Graminées, famille du blé

Genus notes The genus Zea is composed of four species. The wild species and subspecies are all termed “teosinte” (Doebley 1990). Several species of the genus Zea may have been used by prehistoric people. Remains from dry caves near Tehuacán in southern Mexico dated at 7000 years B.P. appear to be Zea stems that had been chewed more or less like sugar cane. This practice still continues in Mexico (Crosswhite 1982). A recently recognized teosinte, Z. diploperennis Iltis, Doebley & Guzmán, is important because it is resistant to four of the nine major viral and mycoplasmal diseases of cultivated corn; it is the only source of resistance for three of these. It also has the same chromosome number as corn and therefore is easier to use in corn breeding than other teosintes. To preserve the important wild habitat of Z. diploperennis, a 140 000 ha nature reserve was created in Mexico’s Sierra de Manantlán Biosphere Reserve, one of only a few such reserves in the world established specifically to preserve in situ wild germplasm of wild crop relatives (Guzmán and Iltis 1991; Small and Cayouette 1992). The domesticated corn, a subspecies of Zea mays, is discussed below.

Names Scientific (Latin) name: Zea mays L. English common name: corn Also: sweet corn, maize, Indian corn [The word maize, derived from American Indians who introduced it to European explorers and settlers, denotes Zea mays in much of the world. The word corn, meaning particle of grain (or indeed of anything) traces to Biblical days. In some countries, corn meant wheat, while in others it meant barley or oats. In North America corn came to mean maize.] French common name: maïs (m) [sweet corn = maïs sucré]

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Description and taxonomy Corn is an annual herbaceous grass. Cultivated corn, Z. mays subsp. mays, includes all types of domesticated corn used for human food, as well as corn used for animal feed and silage. Races of domesticated corn have been recognized. They include regional variations that have been used to interpret the routes of dispersal of domesticated corn in antiquity (Sanchez and Goodman 1992a, 1992b). Wild forms of Z. mays are known from Mexico and Guatemala and, like the other three exclusively wild species of Zea, are all termed “teosinte.” The subspecies of Z. mays are differentiated on traits that can vary depending on growing conditions, and thus the groups are not always easy to identify (Doebley 1990; Francis 1990). The subspecies include subsp. mexicana (Shrader) Iltis, an annual teosinte from the highlands of central and northern Mexico, characterized by large spikelets subsp. parviglumis Iltis & Doebley, an annual teosinte from river valleys of southwestern Mexico, characterized by small spikelets subsp. huehuetenangensis (Iltis & Doebley) Doebley, similar to subsp. parviglumis but more robust and later-blooming, from western Guatemala Domesticated corn probably originated in southern or central Mexico and is most closely related to the wild annual teosinte, subsp. parviglumis (Doebley 1990). Well-known evidence for early use of Zea has come from 7000-year-old dry caves in Mexico’s Tehuacán Valley (Crosswhite 1982), and still earlier finds have been uncovered. The first types may have resembled teosinte, with each kernel covered by husk; they probably differed from modern corn also in being able to disperse the kernels. In fact, modern corn would likely not survive for many generations in the wild because the protective husk is firmly attached to the cob, making seed dispersal impossible. Corn, long used as a source of flour by native Americans in North and South America, remains a staple in the diet of many native groups (Brown and Robinson 1992). Sweet-tasting corn, which arose from time to time, was preserved by native Americans, many of whom used corn daily for food. Sweet corn is distinguished from other corns by genes for high sugar content. In 1779, a sweet corn was brought back from an expedition against the Six Nations Indians, from the Susquehanna region of Pennsylvania. It was called “papoon” by the Indians. The first commercial cultivar of sweet corn, developed from this source, was released in the northeastern United States in 1832. Since then more than 2000 cultivars have been selected, firstly as predominantly white-kerneled varieties and, after the release of Golden Bantam in 1902, increasingly yellow-kerneled cultivars. Hybrid sweet corn was developed in the 1930s, which has led to high-quality, uniform, and productive corn cultivars. In the 1970s, the “supersweet” corns were introduced. In these the starch gene was replaced by super-high or high sugar genes (see below).

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Sweet corn is now divided into three major classes based mainly on amount of sugar and the conversion rate of sugar to starch after harvest (Wiley et al. 1989), as follows: Sugary normal (su). This corn type contains the sugary (su) gene that blocks conversion of sugar (mostly sucrose) to starch after moving from the leaves to the kernels. It is the most common type of sweet corn. Sugary enhanced (se). This corn has very tender kernels, which, although desirable for consumers, are too tender for mechanical harvest or long-distance shipping. The se gene causes sugar to convert to starch at a slower rate. It also increases the sugar maltose in the kernels, which contributes a distinctive flavor that many find desirable. The se types have darker green husks, are better adapted to cold, and require less isolation than the supersweet corn described below. Sweet gene hybrids. These hybrids have 50% increased sweetness over sugary normal corn, which is achieved by producing kernels with 75% sugary normal (su) and 25% shrunken 2 (sh2) gene described here. Supersweet hybrids (sh2). Most of these cultivars can be mechanically harvested and are used in large quantities by processors for canning or freezing. The cobs have pale green husks, and seed vigor is only fair in cool weather. These corns have twice the sugar content of su and do not convert sugar to starch after harvest. Isolation is critical to prevent cross-pollination, which results in loss of sugar content upon maturity. Neither this nor the next class of corn contain water-soluble polysaccharides, resulting in somewhat more watery, less creamy kernels. Improved supersweet hybrids (Also called the Sweetie class). This genetic combination of su and sh2 in the harvested ear results in corn 20% sweeter than the supersweets and almost 125% sweeter than sugary normal corn. Corn plants are monoecious (having separate male and female flowers on the same plant). The male flowers, corresponding to the “tassels,” are usually located at the top of the main shoot. The female flowers, making up the “ear,” are located in the axils of lower leaves. Corn is normally cross-pollinated, the male flowers on a given plant shedding pollen several days before the female flowers become receptive (Nonnecke 1989).

Uses Corn has been used as human food for thousands of years, usually ground as flour for breads, cakes, and other staple foods. When immature, it was commonly used as a vegetable by eastern American woodland Indians. Such consumption of whole immature cobs is seen currently in some parts of the world, such as in southeast Asia, and the small whole cobs are often served as a cocktail or gourmet dish. Sweet corn is an important fresh and processed vegetable in North America. Native Americans were also familiar with popping corn

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(Anderson 1991), which is now a familiar snack food. Corn is also processed to provide such items as corn chips and tortillas and is used in many breakfast cereals. Corn is one of the most widely used crop plants. Some cultivars are important for animal feed. Corn is also processed into flour, starch, oil, syrup, and sugar, and many more specialized products are produced from corn constituents such as furfural, acetone, maltose, and butyl alcohol. Components of corn are used in paper, adhesives, textiles, charcoal, medicines, fuels, soft drinks, ice cream, peanut butter, salad dressing, gelatin, and other products (Alexander 1989; Nonnecke 1989; Wiley et al. 1989). Example recipes

Corn and chive soufflé (Morash 1982) Corn chowder (Morash 1982) Corn quiche (Morash 1982) Corn salad with peppers (Levy 1987) Corncob syrup (Morash 1982) Spicy chicken in corn sauce (Morash 1982) Succotash (Morash 1982)

Importance Estimates of the value of corn used for human, animal, and industrial uses are US$55 billion a year worldwide (Tenenbaum 1988). Of all the crops in the world, this value is exceeded only by wheat, and possibly also rice. Sweet corn is very important in North America, less so elsewhere. Among the vegetable crops in the United States, sweet corn ranks second in farm value for processing and fourth for fresh market. About 250 000 ha of sweet corn are grown in the United States (Wiley et al. 1989). In Canada, sweet corn represents about 10% of the total corn market. About two thirds of the sweet corn is processed and the remainder sold in the fresh market. About 90% of Canada’s fresh sweet corn is grown domestically. More than 80% of Canadian sweet corn production occurs in Ontario and Quebec (Coleman et al. 1991).


For best results, corn requires well-drained loamy or silty-loam soils, high in organic matter. Corn is a shallow-rooted crop so that low-lying areas, subject to flooding, should be avoided. Corn is a heavy feeder of nutrients. Soil tests are desirable, especially in commercial production. Crop rotation is recommended, and corn fits well into a 4-year rotation that includes a legume or green manure crop (Anonymous 1988a; Nonnecke 1989).

Climate

Sweet corn requires a minimum soil temperature of 10°C for germination and subsequent root development. The optimum range is 21–27°C. Germination can be accelerated by planting seed in plastic-covered trenches. Corn requires bright, hot days for best

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growth. The optimum air temperature for corn growth is 21–30°C. The amount of heat necessary for corn crops (in excess of 10°C) is measured in “corn heat units” (CHUs). These have been calculated for corn-growing areas and indicate which cultivars are suitable locally. In general, early sweet corn requires 1900 CHUs, mid-season cultivars need 2000–2100 CHUs, and late-season cultivars 2200–2300 CHUs. Corn needs a good, even supply of moisture, particularly during pollination and as early cobs form. Care must be taken when irrigating to avoid water droplets interfering with the pollination process (Wiley et al. 1989; Anonymous 1988a; Nonnecke 1989). Propagation and cultivation

Propagation of corn is by seed. For good production, seeds should be planted when soil temperatures are above 18°C. Soil should be moist. Seeding rates are recommended at 20% above the normal suggested rate to ensure germination of adequate numbers of plants. Seeds are shallow-planted about 1–2 cm deep. A cover of clear plastic mulch can advance maturity of corn by 10–14 days. Corn seeds are usually coated with a fungicide to prevent growth of pathogens in the cooler moist soils common in many parts of Canada. This treatment allows earlier planting in some areas. Because corn is usually cross-pollinated, stray pollen grains from other types of corn can alter the uniformity of color or increase undesirable starch in the kernels. Therefore, sweet corn should not be grown near other types of corn (Nonnecke 1989). In fact, it is recommended that the supersweet corn cultivars should either be grown at least 75 m from normal sweet corn, or, if planted within 75 m, a 2-week difference of tasseling time from that of other corn cultivars should be arranged (Anonymous 1988a). To ensure an extended market period, it is advisable to plant several cultivars having different maturity dates. Sweet corn has a host of pathogens, insects, and weeds. For their control, it is important to follow local guidelines.

Harvest and storage

Commercial sweet corn for processing or fresh market must be harvested at peak quality, which is generally about 21 days after the silks appear, unless unusual weather has occurred. Processors use various devices to test prime maturity of sweet corn (Nonnecke 1989), of which the following are particularly useful: refractometer, an instrument that measures total soluble solids succulometer, a laboratory instrument that computes the amount of juice in the kernels Steinlite, Brown-Duvals, Brabender oven, an instrument that provides a measure of moisture content

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Lee-Kramer-Shear press, a laboratory instrument measuring firmness or tenderness. Commercial harvesting is done mechanically. The latest harvesters cut rather than snap the ears, cut 1 or 2 rows, and allow for night harvest, when the field heat of corn is lowest. In fact, hand harvesting is generally uneconomical because of the extra time taken and losses from deterioration caused by high field temperatures. The rate of respiration of husk and cob is 20 times as rapid at 33°C as at 21°C. Sweet corn temperature should be reduced to 0°C as soon as possible by hydrocooling, accomplished by passing the corn through iced water on slow conveyor belts. Twenty-five minutes are required to reduce cobs from 30°C to 4°C. Sweet corn has a shelf life of 6–8 days when held at 0°C and relative humidity of 90–95%. If corn is displayed partially or wholly unhusked, the cobs must be covered with perforated film to prevent moisture loss while allowing for dissipation of gases and the heat of respiration (Anonymous 1988a; Nonnecke 1989).

Example cultivars

Sugary normal (su) (regular tasting sweet corn, including extra early, early, and main season hybrids): yellow kernels: Aztec, Buttervee, Earlivee, Flavorvee, Golden Jubilee, Norsweet, Northern Vee, Seneca Northern, Spirit, Springdance, Stylepak white kernels (some are heterozygous se types with cobs containing 25% sugar enhanced se kernels and 75% sugary normal su): Casper II, Platinum Lady, Spring Crystal bicolor kernels: Burgundy Delight, Classic Touch, Early Gold & Silver, Metis Horizon, Peaches And Cream Early, Pride And Joy, Seneca Dawn Sugary enhanced (se) (use should be limited to pick-your-own and roadside stands or local markets because this class reacts poorly to stress and the tender kernels are easily damaged): yellow kernels: Bodacious, Flavor Queen, Kandy Treat, King Arthur, Miracle, Sugar Buns, Tendertreat white kernels: Divinity, Snow Sweet, Sugar Snow bicolor kernels: D’Artagnan, Gemini, Kiss And Tell, Speedy Sweet. Supersweet (sh2) (cultivars must be isolated from all other corn to retain their special sweet quality): yellow kernels: Bunker Hill, Illini Early Xtra Sweet, Northern Super Sweet, Northern Xtra Sweet, Sweet Dreams. Ayad et al. (1980) listed institutions preserving germplasm of corn. Facciola (1990) provides an extensive description of classes of corn and of cultivars available in the United States. Malo and Bourque (1992) described cultivar trials conducted in Montreal. Sweet corn breeding was discussed by Kaukis and Davis (1986). Baillargeon and Fraleigh (1992) inventoried Canada’s national corn germplasm collection.

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Additional notes Plant breeders used cytoplasmic male sterility found in one Texas corn line to eliminate the labor costs of detasseling (removing the male flowers) to prevent self-fertilization. This work resulted in complete and inexpensive control of hybrid crosses in corn breeding programs. By the late 1960s, virtually all commercial corn sold in the United States was based on cultivars with the Texas cytoplasmic sterility. In the summer of 1970, a mutant form of a blight fungus spread north across the United States at the rate of 80 km or more a day, attacking all corn possessing the male sterility. This near-disaster has led to the use of more races of corn, and breeding with the recently discovered Z. diploperennis to provide genetic diversity (Crosswhite 1982). Photosynthesis in corn is of a type characteristic of certain plants of hot countries. Corn has the Krantz-type, four-carbon (C4) metabolic pathway. This type provides for efficient photosynthesis under conditions of high light intensity and high temperatures. Sweet corn, which is mainly grown at high latitudes, does not have as well-developed Krantz-type features as other C4 grasses, including other types of corn (Francis 1990). Curiosities

Corn was one of the fastest imports to become popular in the Old World after the discovery of the New World. It has been said that only two other New World “products,” tobacco and syphilis, spread with equal rapidity. Pilgrims ate popcorn at the first Thanksgiving dinner. Corn pollen grains are the largest among the grass family. Corn produces pollen in prodigious amounts. It has been estimated that an average of 6600 pollen grains are developed from each square centimetre (42 500 per square inch) in a cornfield. An old custom of Great Lakes Indians formed the basis of Longfellow’s account of how a naked Minnehaha dragged her principal garment three times around a corn field at night to repel evil spirits, harmful birds, and insects. In 1622, Native Americans killed a third of the Virginia population of European settlers in retaliation for their encroachment on Indian cornfields (Root 1980). The first certain account of plant hybridization was provided in a letter written in 1716 by Cotton Mather, in which he discussed odd character combination in corn. Simply because of variation in the size of the cob, a slender ear of corn may have as many kernels as a thicker ear. The explorer George Catlin, who spent many years among the Mandan Indians of the Upper Missouri and Upper Mississippi Rivers in the 1840s, gave the following account of corn culture (Catlin

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1844): “They raise a very small sort of corn, the ears of which are not longer than a man’s thumb …. The green corn season is one of great festivity with them, and one of much importance. The greater part of their crop is eaten during these festivals and the remainder is gathered and dried on the cob, before it has ripened, and packed away in ‘caches’ (as the French call them), holes dug in the ground, some 6 or 7 feet deep, the insides of which are somewhat in the form of a jug, and tightly closed at the top.” Sweet corn is the leading canned vegetable in the United States (Root 1980). Barbara McClintock received the Nobel Prize in 1983 for her work with the complex color patterns of Indian corn, studies that revealed moveable genetic elements termed “jumping genes.” It has been said that scientists understand more about corn genetics than the genetics of any other flowering plant (Ewan 1969). Corn was grown in outer space, on the Atlantis shuttle that circled the Earth for 5 days in 1989 (Stanley 1992). In the absence of light, corn seedlings grew sideways in space, reflecting the importance of gravity on earth for normal plant growth. Roots did not grow downwards, and the shoots tied themselves into knots. Had light been provided, the shoots probably would have grown towards the light.

Problems and potential Corn is susceptible to a number of disease pathogens and insect pests. McGee (1988) discussed disease pathogens of corn in North America. Only 3.7% of processing corn and somewhat more than 7% of corn destined for the fresh market is imported into Canada (Coleman et al. 1991; Anonymous 1992a), which is substantially self-sufficient for sweet corn production. Efforts could be made to develop foreign markets in Europe and Asia where sweet corn in underused because it is often associated with field or “animal” feed corn. However, considering the short season of Canada, and the existence of the competitive corn belt in the United States, expanding production of sweet corn in Canada seems difficult.

Selected references Wiley et al. 1989; Doebley 1990; Francis 1990.

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Index of English names The recommended names of the principal vegetables discussed in this book are indicated in bold type. Most Asian-language names have not been included unless they are very well established in English; for these, see the index of Asian names. alfalfa, 271 purple-flowered, 271 tree, 270 variegated, 271 yellow-flowered, 271 allgood, 142 all-good, 144 amaranth, 43 red, 43 Suriname, 43 vegetable, 43 ampalaya, 279 anise, 203 sweet, 203 apple, Canada, 214 Jew’s, 331 mad, 331 melon, 162 arracacha, 5 artichoke, 188 Chinese, 5 globe, 188 Jerusalem, 213 Syrian, 185 arugula, 199 asparagus, 17, 61 common, 61 garden, 61 Italian, 115 aubergine, 331 barley, 4 basella, 73 bean, 16 adsuki, 371 adzuki, 5, 371 army, 302 asparagus, 376 black, 298 broad, 364, 365 butter, 303 Carolina, 303 catjang, 376 Chinese long, 376 civet, 303 common, 297, 364 cranberry, 298 Dutch case-knife, 306 English, 364 European, 364

faba, 364 fava, 364 field, 364 French, 297 garbanzo, 4 great northern, 298 green, 297 Guinea, 240 horse, 364 kidney, 297, 298 lima, 302 Mambi, 371 mat, 371 miracle, 212 moth, 371 mung, 372 navy, 302 New Guinea, 240 pea, 298 pink, 298 pinto, 297, 298 potato, 47 red, 298 rice, 371 Romano, 297 runner, 297 salad, 297 scarlet runner, 306 sewee, 303 sieva, 303 snap, 297 soja, 207 soya, 207 string, 297 Tasmania, 240 tepary, 297 tick, 364 wax, 297 wild, 47 Windsor, 364, 365 wonder, 212 yard-long, 376 year, 297 yellow eye, 298 beet, 16, 82 fodder, 79 leaf, 80 seakale, 80 silver, 80 sugar, 82 beetroot, 82

bellflower, creeping, 134 bird’s-nest, 194 blue sailors, 151 borecole, 88, 91, 119, 120 thousand-head, 90 broccoflower, 88, 104, 115, 118 broccoli, 16, 89, 114 bouquet, 88, 91 Chinese, 88, 91, 92, 119, 120 green, 115 green-sprouting, 88, 91 heading, 88, 91 Italian turnip, 91 perennial, 88, 91 purple-sprouting, 88, 91 sprouting, 88, 91 true-heading, 88, 91 turnip, 118 white-sprouting (early), 88, 91 white-sprouting (late), 88, 91 broccoli raab, 89, 91, 115, 118 Brussels sprout(s), 16, 88, 109 buckwheat, 4 bur, butter, 5 burdock, edible, 58 great, 58 bush-kale, 120 butter vine, New Guinea, 242 cabbage, 16, 88, 90, 91, 105 celery, 89, 91, 92, 127 Chinese, 89, 91, 92, 127 green, 105 mibuna, 126 michihli, 92, 127 mizuna, 126 nappa, 92, 127 Portuguese, 88 red, 105 savoy, 88, 90, 91, 106, 109 swamp, 226 calabase, 242 calabash, 240 tree, 243 calabrese, 88, 91, 115 canna, 5 canola, 90, 96 cantaloupe, 161, 162 cardone, 185 cardoni, 185

408 cardoon, 185 carrot, 16, 192 Peruvian, 5 cauliflower, 16, 88, 90, 91, 101 sprouting, 115 celeriac, 55 celery, 17, 51 knob, 55 roots, 55 turnip root, 55 turnip-rooted, 55 water, 228 celery knob, 55 celtuce, 234, 235 chanterelle, 4 chard, 80 Swiss, 79 chervil, turnip-rooted, 5 chick-pea, 309 chicory, 151 Italian, 151 Magdeburg, 152 red, 151 red-leaved, 151 witloof, 151 chioggia, 151 chives, 28 Chinese, 28 garlic, 28 chop suey green, 145 chrysanthemum, garland, 145 clover, Chilean, 278 cocona, 330 cole, sea, 157 colewort, 119, 157 collard, 88, 91, 119, 120 colza, Indian, 90 convolvulus, Chinese, 226 corn, 16, 379 Indian, 379 sweet, 379 corn salad, 361 blond, 361 common, 361 green, 361 hairy-fruited, 361 Italian, 361 shell, 361 corn-salad, 361 cowcumber, 171 cowpea, 376 crambe, 157 cress, American, 70 Belle Isle, 70 common winter, 70 curled, 247 early winter, 70 garden, 245 land, 70

Vegetables of Canada pepper, 247 upland, 70, 245 water, 285 winter, 70 crown-daisy, 145 crummock, 327 cuckold, 58 cucumber, 16, 167 African, 164 African horned, 161, 164 bitter, 279 burpless, 168 Chinese, 161, 162 common, 161 English, 167 field, 168 forcing, 168 greenhouse, 167 horned, 164 Oriental pickling, 162 pickling, 167 Sikkim, 168 spiny bitter, 279 yard-long, 164 cucuzzi, 240 currant, 263 daisy, crown, 145 dandelion, 351 French, 353 dulse, 4 eggplant, 331 scarlet, 330 endive, 148 Belgian, 151 Brussels, 151 French, 151 escarole, 148 fat-hen, 142, 144 fennel, bronze, 205 Florence, 202 sweet, 205 fenugreek, 4 fern, asparagus, 61 bracken, 267 ostrich, 264 shuttlecock, 264 fetticus, 362 fiddlehead, 264 finocchio, 202 flower, tassel, 43 fodder-radish, 319 frijol, 297 garlic, 28 Canada, 28

elephant, 30, 31 great-headed, 30 gherkin, 167 West Indian, 161 gilo, 330 girasole, 213 glasswort, 5 goat’s beard, purple, 358 gobo, 24, 58 gombo, 24 good King Henry, 142, 144 good-Henry, 142 good-King-Henry, 142 goosefoot, 142 Mercury, 144 gourd, ash, 76 bottle, 240 calabash, 240 dishcloth, 251 fuzzy, 76 hedged, 164 Italian edible, 240 leprosy, 279, 282 sponge, 251 wax, 76 white, 76 white-flowered, 240, 243 gram, black, 371 golden, 372 green, 372 grass, pepper, 247 scurvy, 70, 157 viper’s, 324 greens, Chinese mustard, 88 mustard, 88, 92, 93, 124 groundnut, 47 gumbo, 24 haricot, 297 harlock, 58 hedgehogs, 270 hemlock poison, 194 water, 291 hop, 219, 349 English, 219 hops, 219 horsebean, 365 huckleberry, garden, 330 jalap, 226 Jew’s apple, 331 jimson weed, 260 kale, 88, 90, 91, 119, 120 Chinese, 88, 91, 92, 119, 120

Index of English names curled kitchen, 88, 91, 119, 120 Italian, 89, 91 kitchen, 120 marrow-stem, 88, 90, 91, 112, 120 Portuguese, 90, 91, 120 ruvo, 89, 91 Scotch, 88, 91, 119, 120 sea, 157 Siberian, 90, 91, 96 thousand-head, 120 tree, 120 turnip, 88, 91 karela, 279 kerela, 279 kiwano, 164 knob celery, 55 kohlrabi, 88, 90, 91, 112 kumba, 330 kurrat, 29 lady’s-finger, 24 lamb’s quarters, 142 lamb’s lettuce, 361 leek, 29 European, 29 Japanese, 39 Turkish, 29 wild, 28 lentil, 4 lettuce, 17, 234 bibb, 234 butterhead, 234 cos, 234 crisphead, 234 field, 361 head, 234 lamb’s, 361 Latin, 235 leaf, 234 loose leaf, 234 miner’s, 283 romaine, 234 stem, 235 loofah, angled, 248 smooth, 251 lucern(e), 271 luffa, angled, 248 smooth, 251 lupine, silky, 4 maca, 245 mâche, 361 blond, 361 green, 361 shell, 361 maiden’s blush, 279 maize, 379 mallow, musk, 24

409 mangel, 79 marihuana, 225, 349 marrow, vegetable, 180 mashua, 5 medic, 270 barrel, 270 disc, 270 gama, 270 snail, 270 strand, 270 tree, 270 medick, 270 melofon, 162 melon, 161 bitter, 279 Chinese bitter, 279 Chinese preserving, 76, 240 Chinese winter, 76 chito, 162 cucumber, 161 fuzzy, 76 honeydew, 162 horned, 164 jelly, 164 suzza, 240 zucca, 240 melong, orange, 162 melongene, 331 mercury, 142 wild, 144 miner’s lettuce, 283 mirabilis, 5 mizuna, 89, 90, 127 morel, 4 mougri-radish, 319 mushroom, 4, 11 oyster, 4 pine, 4 muskmelon, 162 mustard, Abyssinian , 89 black, 89 broad-beaked, 92 brown, 89 celery, 89, 92, 127 Chinese, 88, 89, 92, 93, 127 Chinese green, 92 Ethiopian, 89 Indian, 89, 93 leaf, 88, 90 pickling, 90 spinach, 88, 92, 123 swollen, 95 turnip, 90, 91 mustard greens, 88, 92, 93, 124 Chinese, 88 nappa, 126, 127 naranjilla, 330 nasturtium, 285

oak, Jerusalem, 142 oat, 4 oca, 5 okra, 24 Chinese, 248, 252 Guineen, 24 onion, 17, 33 catawissa, 34, 39 Chinese small, 38 common, 33 common, aggregatum group, 34 common, ever-ready group, 34 Egyptian, 28, 34, 39 green bunching, 38 green tail, 38 Japanese bunching, 34, 38 multiplier, 34 pearl, 30 potato, 34 Spanish, 36, 38 spring, 38, 41 top, 34, 39 tree, 34, 39 two-blade, 38 wakegi, 34, 39 Welsh, 38, 42 orach, 67 garden, 67 orange, vegetable, 162 oyster plant (oyster-plant), 358 black, 324 Spanish, 5, 324 true, 324 oyster, vegetable, 358 palm, date, 349 papoon, 380 parsley, Dutch, 294 Hamburg, 294 rooted, 294 turnip-rooted, 294 parsnip, 16, 290 pawnee, 362 pea, 16, 309 black-eyed, 309, 376 chick, 4 common, 309 edible-podded, 310 English, 309 field, 309, 310 garden, 309 grass, 4 green, 309 pigeon, 364, 365 snow, 309, 310 sugar, 310 tick, 364 peach bells, 134 peach, vine, 162

410 peanut, 4, 47 pear, balsam, 279 pepino, 330 pepper, 17, 137 bell, 137 bird, 138 cayenne, 138 chile, 138 green, 137 pimento, 138 tabasco, 137 pepper-grass, common, 245 peppergrass, 245 pickle, mango, 162 plant, oyster, 358 potato, 11, 335 Canada, 214 Irish, 335 sweet, 229 white, 335 prince’s feather, 43 pumpkin, 173, 175, 180 white, 76 purslane, 315 summer, 315 winter, 283 pursley, 315 pusley, 315 Queen-Annes’s-lace, 194 quinoa, 142 raab, spring, 89, 91, 115 radicchio, 151 radichetta, 151 radish, 16, 318 aerial, 319 black, 319 Daikon, 322 fodder, 319 large, 319 mougri, 319 oil, 319 rat-tailed, 319 serpent, 319 small, 318 rampion, 134 ramps, 134 rape, 90 forage, 96 Indian, 90 rapini, 89, 91, 115, 130 rappini, 115, 130 rice, wild, 4, 268 rocket, 70, 199 Mediterranean, 199

Vegetables of Canada salad, 199 yellow, 70 rocket-salad, 199 root, celery, 55 roquette, 199 rucola, 199 rugula, 199 rutabaga, 16, 88, 96 salad, field, 361, 362 Hanover, 90, 91, 96 salsify, 324, 358 black, 324 Spanish, 324 sarson, 125 yellow, 90 savoy, Chinese, 89, 91, 92, 127 scorzonera, 324 shallot, 34 shitake, 4 shum, 330 skirret, 327 sowpea, 376 soybean, 207 spinach, 17, 346 Ceylon, 73 Chinese, 43 Cuban, 283 French, 67 Indian, 73 Malabar, 73 mountain, 67 mustard, 88 New Zealand, 355 vine, 73 water, 226 wild, 142 sponge, common vegetable, 251 sprouts, bean, 372 squash, 173, 175, 180 crookneck, 178 winter, 173, 175, 178 strawberry blight, 142 succory, 151 sunchoke, 213 sunflower, 213 swede, 88, 96 tail, green, 38 tampala, 44 tea, Mexican, 142 tendergreen, 88, 92, 123 tender green, 92 teosinte, 379 thistle,

artichoke, 185 edible, 185 tickpea, 365 tomato, 11, 254 cherry, 254 currant, 261 English, 164 husk, 260 peach, 330 strawberry, 260 tree, 260 toria, 90 tree, calabash, 243 turnip, 89, 90, 91, 130 Italian, 89 seven-top, 89, 91 summer, 130 Swedish, 96 winter, 96 ulluco, 5 urd, 371 vegetable-oyster, 358 vetch, common, 364 hairy, 364 Hungarian, 364 wooly-pod, 364 vine, New Guinea butter, 242 viper’s grass, 324 watercress, 285 true, 288 watermelon, Chinese, 76 weed, jimson, 260 wet-a-bed, 354 wheat, 4 wild mercury, 144 willow bell, 134 witloof, 151 wonderberry, 330 woolly-pod vetch, 364 wormseed, 142 wort, cole, 120 yacon, 5 yam, 229 year-bean, 297 zucca (melon), 240 zucchini, 180

Index of French names The recommended names of the principal vegetables discussed in this book are indicated in bold type. ail fistuleux, 38 amarante de Chine, 43 ansérine Bon-Henri, 142 apios d’Amérique, 47 arroche, 67 Bon-Henri, 142 épinard, 67 artichaut, 58, 188 asperge, 61 aubergine, 331 barbe-de-capucin, 151 bardane majeure, 58 baselle, 73 batatas du Canada, 214 berle des potagers, 327 bette, 80, 82 à carde, 80 à côtes, 80 poirée, 80 betterave, 82 poirée, 80 potagère, 82 sucrière, 82 blète, 80 blette, 80 bok-choy, 126 brocofleur, 115 brocoli, 114 chinois, 119 calebasse, 240 carde, 80 poirée, 80 cardon, 185 carotte, 192 céleri, 51 celéri-rave, 55 chervi, 327 chervis, 327 chicorée, 151 endive, 148 rouge, 151 sauvage, 151 scarole, 148 chop soui vert, 145 chopsouy vert, 145 chopsuy vert, 145 chou, 105 blanc, 106 de Bruxelles, 109 cabus, 106 cavalier, 119 chinois, 126

frisé, 106, 119 marin, 157 de Milan, 106 pommé, 105 rouge, 106 de Savoie, 106 de Siam, 96 vert, 106, 119 vert frisé, 119 chou-fleur, 101 chou-navet, 96 chou-navet blanc, 96 chou-rave, 112 chrysanthème des jardins, 145 ciboule, 38 citrouille, 173, 175, 180 claytone de Cuba, 283 collard, 119 concombre, 167 anglais, 167 Angurie, 161 chinois, 162 à cornichons, 161 de serre, 167 cornichon, 167 courge, 173, 175, 180 bouteille, 240 à la cire, 76 musquée, 178 courge-torchon, 251 crambe, 157 maritime, 157 crambé, 157 maritime, 157 cresson, 285 alénois, 245 de fontain, 285 de jardin, 70, 245 de terre, 70 crosse de fougère, 264 dent de lion, 351, 354 dent-de-lion, 351 dolique asperge, 376 doucette, 361 endive, 151 épinard, 346 de Malabar, 73 de la Nouvelle-Zélande, 355 sauvage, 142 escarole, 148 fève des marais, 364

féverole, 364 foenouil de Florence, 202 fougère de l’autruche, 264 germes, de haricot, 372 de haricot mungo, 372 gombo, 24 chinois, 248 gourgane, 364 grande bardane, 58 graquias, 58 haricot blanc, 297 commun, 297 jaune, 297 de lima, 303 mange-tout, 297 mungo, 372 à rames, 306 de Siéva, 303 vert chinois, 376 herbe de Sainte Barbe, 70 houblon, 219 laitue, 234 asperge, 234 beurre, 234 frisée, 234 pommee, 234 romaine, 234 luffa, 248, 251 luzerne, 271 mâche, 361 commune, 361 maïs, 379 sucré, 379 margose, 279 matteucie fougère-à-l’autruche, 264 melon à cornes, 164 velu, 76 metulon, 164 mizuna, 126 mogwa, 76 momordique à feuilles de vigne, 279 moutarde brune, 93 de Chine, 93 chinoise, 93 de l’Inde, 93 de Sarepta, 93 moutarde-épinard, 123

412 nappa, 126 navet, 96, 130 blanc, 96 oignon, 33 de Strasburg, 38 d’hiver, 38 okra, 24 pak-choï, 126 panais, 290 papengaye, 248 patate, 229, 335 aquatique, 226 douce, 229 patates en chapelet, 47 pé-tsaï, 126 pénacs, 47 persil à grosse racine, 294 petit pois, 309 pétole, 251 piment, 137 doux, 137

Vegetables of Canada pissenlit, 351, 354 poire de merveille, 279 poireau, 29 perpétuel, 30 pois, 309 mange-tout, 309 poivron, 137 pomme du Canada, 214 de terre, 335 pourpier, 315 d’hiver, 283 potager, 315 rabiole, 96, 130 radicchio, 151 radis, 318 noir, 318 raiponce, 134 rampon, 134 rapace, 58 rapini, 115 rhubarbe sauvage, 58

roquette, 199 rutabaga, 96 salsifis, 358 blanc, 358 noir, 324 des prés, 358 savoie de Chine, 126 scarole, 148 scorsonère, 324 soja, 207 soya, 207 tête de violon, 264 tétragone, 355 tomate, 254 groseille, 261 topinambour, 213, 217 toques, 58 valérianelle, 361

Index of scientific (Latin) names The recommended (correct) names of the principal vegetables discussed in this book are indicated in bold type. Abelmoschus, 24 esculentus, 24 manihot, 24 moschatus, 24 tuberculatus, 24 Agaricus bisporus, 4 Allium, 28 aggregatum, 34 altaicum, 39 ampeloprasum, 29 ampeloprasum subsp. ampeloprasum, 29 ampeloprasum subsp. iranicum, 30 ampeloprasum subsp. truncatum, 30 ampeloprasum var. ampeloprasum, 30 ampeloprasum var. babingtonii, 30 ampeloprasum var. bulbiferum, 30 ampeloprasum var. sectivum, 30 ascalonicum, 34 canadense, 28 cepa, 33 cepa subsp. australe, 33 cepa subsp. cepa, 33 cepa subsp. orientale, 34 cepa var. ascalonicum, 39 cepa var. cepa, 33 cepa var. perutile, 34 chinense, 29 fistulosum, 38 fistulosum var. viviparum, 39 kurrat, 29 porrum, 29 ×proliferum, 28, 34, 39 sativum, 28 schoenoprasum, 28 tricoccum, 28 tuberosum, 28 wakegi, 34, 39 Amaranthus, 43 caudatus, 43 cruentus, 43 dubius, 43, 44 gangeticus, 44 hybridus, 43, 46 hybridus var. erythrostachys, 43 salisifolius, 44 tricolor, 43 tricolor subsp. mangostanus, 44 Apios, 47 americana, 47 Apium, 51 graveolens var. dulce, 51

graveolens var. rapaceum, 55 graveolens var. secalinum, 51 Arachis hypogaea, 4, 47 Arctium, 58 lappa, 58 lappa var. edule, 58 minus, 58 Arracacia xanthorrhiza, 5 Asparagus, 61 acutifolius, 61 officinalis, 61 officinalis subsp. officinalis, 61 officinalis subsp. prostratus, 61 officinalis var. altilis, 61 Atriplex, 67 hortensis, 67 hortensis subsp. desertorum, 67 hortensis subsp. hortensis, 67 hortensis subsp. nitens, 67 hortensis var. atrosanguinea, 68 nitens, 67 Avena sativa, 4 Barbarea, 70 praecox, 70 verna, 70 vulgaris, 70 Basella, 73 alba, 73 cordifolia, 73 rubra, 73 Benincasa, 76 hispida, 76 Beta, 79 vulgaris subsp. maritima, 79 vulgaris subsp. cicla, 79 vulgaris subsp. vulgaris, 82 Brassica, 87 alboglabra, 88, 91, 92, 119, 120 campestris, 88, 89, 96, 123, 125, 127 campestris subsp. chinensis, 89 campestris subsp. nipposinica, 89 campestris subsp. pekinensis, 89, 127 campestris subsp. rapifera, 90, 130 campestris subsp. trilocularis, 90 campestris var. dichotoma, 90 campestris var. narinosa, 89, 127 campestris var. nipposinica, 127 campestris var. rapifera, 89 carinata, 89 cretica, 115 dubiosa, 88 juncea, 88, 89, 90, 91, 92, 93, 124

napobrassica, 96 napus, 88, 90, 96 napus subsp. napus, 90, 91, 96 napus subsp. oleifera, 90, 96 napus subsp. pabularia, 96 napus subsp. rapifera, 88, 96 napus var. napobrassica, 88, 96 napus var. napus, 90 napus var. oleifera, 96 napus var. pabularia, 90 nigra, 89 oleracea, 88, 90, 100 oleracea subsp. alboglabra, 88 oleracea subsp. oleracea, 100, 112 oleracea var. acephala, 88, 120 oleracea var. alboglabra, 88, 120 oleracea var. botrytis, 88, 90, 91, 101 oleracea var. botrytis × var. italica, 88 oleracea var. capitata, 88, 90, 91, 105, 106, 124 oleracea var. chinensis, 89, 127 oleracea var. costata, 88, 91 oleracea var. gemmifera, 88, 109 oleracea var. gongylodes, 88, 90, 91, 112 oleracea var. italica, 88, 91, 114 oleracea var. medullosa, 88, 90, 91, 112 oleracea var. oleracea, 101, 102, 115, 120 oleracea var. sabauda, 88, 90, 91, 106, 109 oleracea var. sabellica, 88, 91, 119, 120 oleracea var. viridis, 88, 90, 91, 119, 120 parachinensis, 89, 127 pekinensis, 89, 127 perviridis, 88, 92, 123 purpuraria, 89 rapa, 89, 90, 92, 125, 126, 127 rapa subsp. chinensis, 89, 91, 92, 126, 127 rapa subsp. dichotoma, 90 rapa subsp. narinosa, 89, 90, 91, 92, 126, 127 rapa subsp. nipposinica, 89, 90, 92, 126, 127 rapa subsp. oleifera, 90, 125, 133 rapa subsp. pekinensis, 89, 90, 91, 92, 126, 127 rapa subsp. perviridis, 88, 123

414 rapa subsp. rapa, 89, 90, 91, 115, 130 rapa subsp. sylvestris, 125 rapa subsp. trilocularis, 90, 125 rapa var. narinosa, 89, 127 ruvo, 89, 91, 115, 116, 118 septiceps, 89, 91 Campanula, 134 persicifolia, 134 rapunculoides, 134 rapunculus, 134 Canna edulis, 5 Cannabis, 225 sativa, 349 Cantharellus cibarius, 4 Capsicum, 137 annuum, 137 annuum var. annuum, 137 annuum var. minimum, 138 baccatum, 137 chinense, 137 frutescens, 137 pubescens, 137 Chaerophyllum bulbosum, 5 Chenopodium, 142 album, 142 ambrosioides, 142 bonus-henricus, 142 botrys, 142 capitatum, 142 quinoa, 142 Chrysanthemum, 145 coronarium, 145 spatiosum, 145 Cicer arietinum, 4, 309 Cichorium, 148 endivia, 148 endivia subsp. divaricatum, 149 endivia subsp. endivia, 148 endivia var. crispum, 148 endivia var. endivia, 149 endivia var. latifolium, 148 intybus, 151 intybus var. foliosum, 151 intybus var. intybus, 152 intybus var. sativum, 151, 152 Cicuta, 291 Claytonia, 283 perfoliata, 283 sibirica, 283 Cochlearia officinalis, 157 Conium maculatum, 193 Crambe, 157 abyssinica, 157 cordifolia, 157 hispanica, 157 maritima, 157 Crescentia cujete, 243

Vegetables of Canada Cucumis, 161 anguria, 161 melo, 161, 162 melo subsp. melo, 162 melo var. agrestis, 162 melo var. conomon, 162 melo var. inodorous, 162 melo var. melo, 162 melo var. reticulatus, 162 metuliferus, 161, 164 myriocarpus, 161 sativus, 161, 165, 167 sativus subsp. agrestis, 168 sativus subsp. sativus, 168 sativus var. hardwickii, 168 Cucurbita, 192 argyrosperma, 173 argyrosperma subsp. argyrosperma, 173 argyrosperma subsp. sororia, 174 ficifolia, 172 fraterna, 181 maxima, 173, 175 maxima subsp. andreana, 176 mixta, 173 moschata, 173, 178 pepo, 173, 180 pepo subsp. ovifera, 181, 242 pepo subsp. pepo, 181 texana, 181 Cynara, 185 cardunculus, 185 scolymus, 188 syriaca, 185 Cyphomandra betacea, 260 Datura stramonium, 260 Daucus, 192 carota, 192 carota subsp. carota, 192 carota subsp. sativus, 192 carota var. atrorubens, 193 carota var. sativus, 192 sativus, 192 Dioscorea, 229 Eruca, 199 vesicaria, 199 vesicaria subsp. sativa, 199 vesicaria subsp. vesicaria, 199 Fagopyrum esculentum, 4 Foeniculum, 202 vulgare, 202 vulgare subsp. piperitum, 202 vulgare subsp. vulgare var. azoricum, 202 vulgare var. azoricum, 202 vulgare var. dulce, 202

Glycine, 207 gracilis, 208 max, 207 soja, 207 Helianthus, 213 annuus, 213 szyszylowiczii,218 tuberosus, 213 Hibiscus esculentus, 24 Hordeum vulgare, 4 Humulus, 219 lupulus, 219, 349 lupulus var. cordifolius, 220 lupulus var. lupuloides, 220 lupulus var. lupulus, 220 lupulus var. neomexicanus, 220 lupulus var. pubescens, 220 Ipomoea, 226 aquatica, 226 aquatica var. aquatica, 226 aquatica var. reptans, 226 batatas, 229 batatas var. apiculata, 230 batatas var. batatas, 230 purga, 226 sagittaefolia, 227 tiliacea, 230 trifida, 230 Lactuca, 234 sativa, 234 sativa var. angustana, 235 sativa var. capitata, 234 sativa var. crispa, 234 sativa var. longfolia, 234 scariola, 235 serriola, 235, 238 virosa, 237 Lagenaria, 240 siceraria, 240 siceraria subsp. asiatica, 240 siceraria subsp. siceraria, 240 Lathyrus sativus, 4 Lens culinaris, 4 Lentinula edodes, 4 Lepidium, 245 densiflorum, 245 meyenii, 245 sativum, 245 sativum subsp. sativum var. crispum, 245 sativum subsp. spinesceas, 246 Luffa, 248 acutangula, 248 acutangula var. acutangula, 248 acutangula var. amara, 248 acutangula var. forskalii, 248 aegyptiaca, 251

Index of Latin (sciencific) names aegyptiaca var. aegyptiaca, 251 aegyptiaca var. leiocarpa, 251 cylindrica, 251 Lupinus sericeus, 4 Lycopersicon, 254 cheesmanii var. minor, 260 esculentum, 254 esculentum var. cerasiforme, 254 esculentum var. esculentum, 254 esculentum var. minor, 260 pimpinellifolium, 261 Matteuccia, 264 struthiopteris, 264 struthiopteris var. pensylvanica, 265 struthiopteris var. pubescens, 265 struthiopteris var. struthiopteris, 265 Medicago, 270 arborea, 270 falcata, 271 intertexta, 270 italica, 270 littoralis, 270 lupulina, 270 media, 271 platycarpa, 270 polymorpha, 270 rugosa, 270 sativa, 271 sativa subsp. falcata, 271 sativa subsp. sativa, 271 sativa subsp. ×varia, 271 scutellata, 270 truncatula, 270 Mirabilis expansa, 5 Momordica, 279 charantia, 279 charantia subsp. abbreviata, 280 charantia subsp. charantia, 280 charantia var. abbreviata, 280 cochinchinensis, 279 cymbalaria, 279 Montia, 283 perfoliata, 283 perfoliata forma parviflora, 283 sibirica, 283 Morchella, 4 Nasturtium, 285 microphyllum, 285 officinale, 285 officinale var. microphyllum, 285 Oenanthe javanicum, 228 Onoclea, 268 Oxalis tuberosa, 5 Palmaria palmata, 4 Pastinaca, 290 sativa, 290

415 subsp. divaricata, 290 subsp. sativa, 290 subsp. sylvestris, 290 subsp. urens, 290 Petasites japonicus, 5 Petroselinum, 294 crispum var. crispum, 294 crispum var. tuberosum, 294 Phaseolus, 297 acutifolius, 297 aureus, 372 coccineus, 306 coccineus subsp. coccineus, 306 coccineus subsp. darwinianus, 306 coccineus subsp. formosus, 306 coccineus subsp. glabellus, 306 coccineus subsp. grieus, 306 limensis, 302 lunatus, 302 lunatus var. lunatus, 303 lunatus var. sylvestris, 303 polyanthus, 297 vulgaris, 297 vulgaris var. aborigineus, 299 vulgaris var. humilis, 298 vulgaris var. mexicanus, 299 Phoenix dactylifera, 349 Physalis, 260 Pimpinella anisum, 203 Piper nigrum, 137 Pisum, 309 humilis, 310 sativum, 309 sativum subsp. elatius, 310 sativum subsp. syriacum, 310 sativum var. arvense, 310 sativum var. macrocarpon, 310 sativum var. sativum, 309 Pleurotus ostreatus, 4 Polymnia sonchifolia, 5 Portulaca, 315 oleracea, 315 oleracea subsp. oleracea, 315 oleracea subsp. sativa, 315 Pteritis, 268 Pteritium aquilinum, 267 Raphanus, 318 caudatus, 319 sativus, 318 sativus var. longpinnatus, 319 sativus var. mougri, 319 sativus var. niger, 319 sativus var. oleifera, 319 sativus var. radicula, 318 sativus var. sativus, 318 Ribes, 263 Rorippa nasturtium-aquaticum, 285 Salicornia europaea, 5

Scolymus hispanicus, 5, 324 Scorzonera, 324 hispanica, 324 Sinapis alba, 93 Sium, 327 sisarum, 327 sisarum var. lancifolium, 328 sisarum var. sisarum, 327 Solanum, 330 ajanhuiri, 330 burbankii, 330 chaucha, 330 cumingii, 331 curtilobum, 330 ethiopicum, 330 gilo, 330 insanum, 331 juzepczukii, 330 lasiocarpum, 330 marginatum, 330 melongena, 331 muricatum, 330 nigrum, 330 phureja, 330 quitoense, 330 sessiliflorum, 330 sparsipilum, 335 stenotomum, 330, 335 tuberosum, 335 tuberosum subsp. andigena, 335 tuberosum subsp. tuberosum, 335 Spinacia, 346 oleracea, 346 oleracea var. inermis, 346 oleracea var. oleracea, 346 Stachys affinis, 5 sieboldii, 5 Struthiopteris, 268 Taraxacum, 351 kok-saghyz, 351, 354 officinale, 351 Tetragonia, 355 tetragonioides, 355 Tragopogon, 358 porrifolius, 324, 358 porrifolius subsp. australis, 358 porrifolius subsp. cupani, 358 porrifolius subsp. porrifolius, 358 Tricholoma magniverale, 4 Trigonella foenum-graecum, 4 Triticum species, 4 Tropaeolum, 285 tuberosum, 5 Ullucus tuberosus, 5 Valerianella, 361 eriocarpa, 361

416 locusta, 361 locusta var. locusta, 361 locusta var. oleracea, 361 Vicia, 364 dasycarpa, 364 faba, 364 faba subsp. equina, 365 faba subsp. eu-faba var. minor, 365 faba subsp. faba, 365 faba subsp. minor, 365 faba var. equina, 365 faba var. faba, 365 faba var. major, 365 pannonica, 364 sati va, 364 villosa, 364

Vegetables of Canada Zea, 379 Vigna, 371 aconitifolia, 371 diploperennis, 379 angularis, 5, 371 mays, 379 mays subsp. huehuetenangensis, mungo, 371 radiata, 372 380 radiata var. setulosa, 372 mays subsp. mays, 380 radiata var. sublobata, 372 mays subsp. mexicana, 380 sesquipedalis, 376 mays subsp. parviglumis, 380 umbellata, 371 Zizania aquatica, 4, 268 unguiculata, 375 unguiculata subsp. cylindrica, 376 unguiculata subsp. dekindtiana, 375 unguiculata subsp. sesquipedalis, 376 unguiculata subsp. unguiculata, 309, 376

Index of Asian language names Some of these names have been taken up in English and/or French. ampalaya, 279 bok choi, 89, 92, 127 bok (pak) choy (choi), 89, 92, 127 bow sum, 89, 92, 127 cee gwa, 248 cee-kwa, 248 chieh lan, 88 ,92 chieh tsai, 88, 92 chirimen, 90 chirimen hakusai, 90 chongee, 89, 92, 127 choy sum, 89 chum soy, 127 daikon, 319, 320, 322 dau gok, 376 dow gok, 376 dow guak, 376

kai lon, 88 kancon, 226 kang kong, 226 karala, 279 katsuo-na, 90 kee chi, 163 ken-chetsai, 90, 91 kereila, 279 kigarashi, 90 komatsuna, 88 Kujyo, 39 kyona, 89, 90, 92, 127 lobok, 319 lo bok, 322 ma uek, 330 mibuna, 89, 90, 92, 127 michihli, 127 mizuna, 89, 90, 92, 127 mogwa, 76

engtsai (green), 226 fu kwa, 279 gai (kai) kay, choy (choi), 88, 92 gai (kai) lon, 88, 92 gai lohn, 88, 92 ghia, 251 gien sok, 44 gobo, 58 guy lan, 88, 92 hakarashi-na, 90 hakusai, 89, 92, 127 hsien shu, 44 hsin pei tsai, 89, 92, 127 hsueh li hung, 90 Hsueh-Li-Hung, 95 Kaga, 39

napa, 89, 92, 127 nappa, 89, 92, 127 nigai uri, 279 no luan tau, 310 pai-tsai, 88, 89, 91, 92, 127 pak-choi, 91 pao, 89, 92, 127 pei tsai, 92, 127 pei-tsai, 89 po leng chieh, 88, 92 Prei anak, 30

shelifong, 90 shih chia wan tou, 310 shiyungiki, 145 shui tsai, 89, 92, 127 shungiku, 145 sic kap woon dou, 310 siew choy, 89, 92, 127 sing-kwa, 248 sze-kwa, 251 taatsai, 89, 127 takana, 88, 90, 92 takinogawa, 58 ta ko tsai, 89, 91, 92, 127 ta li wan tou, 310 tampala, 44 tanghoe, 145 Taree Irani, 30 tashin-chetsai, 90 ta-sin-t’sai, 90 tsaishin, 90 tsa-tsai, 90 tse tai tsai, 89 tunka, 76 tze tsai hua, 89 ung choy, 226 uri, 163 wai lon, 92 won bok, 89, 92, 127 wong bok, 89, 92, 127

rakkayo, 29 santosai, 90 saya-endo, 310 Senju, 39 serifong, 90, 95

Yagura, 39 yueh kua, 163 zit-kwa, 76

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