HORTICULTURAL REVIEWS VOLUME 8 Horticultural Reviews is co-sponsored by the American Society for Horticultural Science and The AVI Publishing Company Editorial Board, Volume 8 C.A. Conover E. Van Wann R.H. Zimmerman HORTICULTURAL REVIEWS VOLUME 8 edited by Jules Janick Purdue University AVI PUBLISHING COMPANY, INC. Westport, Connecticut Copyright 1986 by @ THE AVI PUBLISHING COMPANY, INC. 250 Post Road East P.O. Box 831 Westport, Connecticut 06881 All rights reserved. No part of this work covered by the copyright hereon may be reproduced or used in any form or by any means-graphic, electronic, or mechanical, including photocopying, recording, taping, or information storage and retrieval systems- without written permission of the publisher. ISSN-0163-7851 ISBN-0-87055-529-4 Printed in the United States of America A B C D E 5 4 3 2 1 0 9 8 7 6 Contents Contributors ix Dedication xi 1 Gaseous Air Pollution and Horticultural Crop Production Douglas P. Ormrod I. Introduction 2 11. Plant Responses 6 111. Genetic and Plant Factors Affecting Sensitivity 16 IV. Environmental Factors Affecting Sensitivity 20 V. Interactions among Gaseous Air Pollutants 23 VI. Combined Effects Other Stresses 25 with VII. Protection against Injury 26 VIII. Volatile Pesticides as Gaseous Air Pollutants 30 IX. Acidic Precipitation-A By-product of Gaseous Air Pollution 30 X. Research Methodology and Data Interpretation 33 XI. Conclusions 35 Literature Cited 36 2 Edible Aroids: Botany and Horticulture Stephen K. O’Hair and Madhevan P. Asokan I. Botany 43 11. Production 58 111. Utilization 78 Literature Cited 89 3 The Effect of Controlled-Atmosphere Storage on the Sensory and Nutritional Quality of Fruits and Vegetables J. Weichmann I. Introduction 101 11. Sensory Qualities 102 V vi CONTENTS 111. Nutritional Quality 108 IV. Physiological Basis of Nutritional Quality Changes 118 Literature Cited 120 4 The Navel Orange Frederick S. Davies I. Introduction 130 11. World Production 131 111. Morphology and Anatomy 132 IV. Effects of Climate 138 V. Fruit Set 140 VI. Fruit Drop 147 VII. Mutations and Cultivars 150 VIII. Planting Density and Rootstocks 156 IX. Cultural Practices 161 X. Postharvest Physiology and Fruit Quality 166 XI. Conclusions 172 Literature Cited 173 5 Nitrogen Metabolism and Utilization in Citrus Tadashi Kato I. Introduction 181 11. Nitrogen Uptake and Nutrition 182 111. Nitrogen Assimilation 187 IV. Translocation of Nitrogen Compounds 193 V. Storage Nitrogen 196 VI. Nitrogen Metabolism at Low Temperatures 203 VII. Diagnosis of Nitrogen Status 204 VIII. Conclusions 206 Literature Cited 207 6 Flowering in Pecan Hazel Y. Wetzstein and Darrell Sparks I. Introduction 217 11. Crop Biology 218 111. Staminate Flower 223 IV. Pistillate Flower 236 V. Dichogamy 243 VI. Abnormal Flowering 245 VII. Factors Influencing Flowering 245 VIII. Summary 250 Literature Cited 251 7 Avocado Flowering T. L. Davenport I. Introduction 257 11. Floral Biology 258 111. Pollination 272 IV. Conclusions 283 Literature Cited 284 CONTENTS vii 8 Chestnut Blight and Its Control Gary J. Griffin I. Introduction 291 11. Hypovirulence in Endothia parasitica 299 111. Blight Control with Hypovirulence 310 IV. Blight Resistance 313 V. Blight Control with Resistance 318 VI. Other Blight Control Methods 321 VII. Influence of Environmental and Cultural Conditions 324 VIII. Summary 328 Literature Cited 329 9 Physiological Responses of Fruit Trees to Pruning A. Mika I. Introduction 339 11. Historical Review 340 111. Shoot Growth 342 IV. Growth Correlations and Apical Dominance 347 V. Mineral Content of Leaves and Fruit 349 VI. Foliage Area, Photosynthesis, and Respiration 350 VII. Carbohydrate Reserves 353 VIII. Hormonal Patterns 354 IX. Water Supply to Shoots, Leaves, and Fruits 356 X. Cold Hardiness 356 XI. Tree Health 358 XII. Flower Bud Formation and Fruiting Potential 359 XIII. Fruit Setting 362 XIV. Yield and Bearing Regularity 363 xv. Fruit Quality 365 XVI. Summary 367 Literature Cited 369 Subject Index 379 Cumulative Subject Index 38 1 Cumulative Contributor Index 39 1 Contributors MADHEVAN P ASOKAN. University of Florida, IFAS, Tropical Research and Education Center, Homestead, FL 33031 T. L. DAVENPORT. University of Florida, IFAS, Tropical Research and Education Center, Homestead, FL 33031 FREDERICK S. DAVIES. Department of Fruit Crops, University of Florida, Gainesville, FL 32611 GARY J. GRIFFIN. Department of Plant Pathology, Physiology and Weed Science, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061 TADASHI KATO.* Shikoku National Agricultural Research Sta- tion, Zentsuji, Kagawa 765, Japan A. MIKA. Research Institute of Pomology, Skierniewice, Poland STEPHEN K. O’HAIR. University of Florida, IFAS, Tropical Re- search and Education Center, Homestead, FL 33031 DOUGLAS P. ORMROD. Department of Horticultural Science, Uni- versity of Guelph, Guelph, Ontario N1G 2W1, Canada DARRELL SPARKS. Department of Horticulture, University of Georgia, Athens, GA 30602 J. WEICHMANN. Institute of Vegetable Crops Science, Technical University of Munich, D-5080 Freising-Weihenstephan, Federal Re- public of Germany HAZEL Y. WETZSTEIN. Department of Horticulture, University of Georgia, Athens, GA 30602 *Present address: National Grassland Research Institute Nishinasuno Tochigi 329-27, Japan. ix Dedication Advances in horticultural technology are made in small increments. They come about when researchers have a clear goal in mind and back their ideas with persistent effort and high-quality, creative research that seeks answers to both applied and fundamental problems. The career of Dr. Abraham H. Halevy testifies to the efficacy of this method. His goal has been no less than the creation of a new industry for his country. This has been accomplished through unrelenting effort. His career comprises significant contributions to horticulture in general and to floriculture in particular. Born on July 17, 1927, in Tel Aviv, Israel, Dr. Halevy received the MS and PhD at the Hebrew University of Jerusalem. Although his doctorate research was in citriculture, he felt that Israel could prosper growing flowers for export because of its favorable climate and the availability of educated growers who could easily adjust to the technical expertise required in floriculture. Thus in 1958 he accepted a postdoctor- ate research fellowship with the Department of Agriculture at US. Beltsville, Maryland, and returned to the Hebrew University the follow- ing year to found and chair the new Department of Floriculture. Dr. Halevy was both father and mother to the Israeli floricultural industry, which now exports millions of dollars worth of cut flowers to Europe and the United States. He conceived the concept, provided scientific under- pinnings through his research, nursed the industry in its infancy, and nurtured a majority of its present teachers and extension workers. The entire faculty in his department consists of his former students. His research interests in floriculture cover a wide spectrum of activi- ties. He is involved in the introduction of new species, new cultural systems, and the development of new handling and shipping proce- dures. He has developed petals as a model system for the study of senescence, and has been a leader in extending vase-life of cut flowers through bud cutting, sucrose pulsing, and opening solutions. This re- xi