WEED SCIENCE Principles and Practices OURTH EDITION Thomas J. Monaco North Carolina State University Raleigh, North Carolina Stephen C. Weller Purdue University West Lafayette, Indiana loyd M. Ashton University of California Davis, California WEED SCIENCE Principles and Practices WEED SCIENCE Principles and Practices OURTH EDITION Thomas J. Monaco North Carolina State University Raleigh, North Carolina Stephen C. Weller Purdue University West Lafayette, Indiana loyd M. Ashton University of California Davis, California This book is printed on acid-free paper. Copyright © 2002 by John Wiley & Sons, Inc., New York. All rights reserved. Published simultaneously in Canada. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except as permitted under Sections 107 or 108 or the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978) 750-4744. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 605 Third Avenue, New York, NY 10158-0012, (212) 850-6011, fax (212) 850-6008, E-Mail: [email protected]. This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is sold with the understanding that the publisher is not engaged in rendering professional services. If professional advice or other expert assistance is required, the services of a competent professional person should be sought. Library of Congress Cataloging-in-Publication Data: Monaco, Thomas J. Weed science : principles & practices / Thomas J. Monaco, Stephen C. Weller, Bloyd M. Ashton.--4th ed. p. cm. Rev. ed. of: Weed science / Bloyd M. Ashton. 3rd ed. c1991. Includes bibliographical references (p. ). ISBN 0-471-37051-7 (cloth: alk. paper) 1. Weeds--Control. 2. Herbicides. I. Weller, Stephen C. II. Ashton, Bloyd M. III. Ashton, Bloyd M. Weed science. IV. Title. SB611.M58 2001 632;5dc21 2001026926 Printed in the United States of America 10 9 8 7 6 5 4 3 2 1 This textbook is dedicated to the memory of each of these authors: Glenn Klingman, &red Warren, and Dan Hess for their tremendous contributions to the advancement of weed science. CONTENTS PREACE ix I. PRINCIPLES 1 1. Introduction to Weed Science 3 2. Weed Biology and Ecology 13 3. Integrated Weed Management 44 4. Herbicide Registration and Environmental Impact 84 5. Herbicides and the Plant 98 6. Herbicides and the Soil 127 7. ormulations and Application Equipment 146 II. HERBICIDES 181 8. Chemistry and Classification of Herbicides by Mechanism of Action 183 9. Photosystem II Inhibitors 198 10. Pigment Inhibitors 223 11. Membrane Disrupters 235 12. Cell Growth Disrupters and Inhibitors 256 13. Cellulose Biosynthesis Inhibitors 284 14. Growth Regulator Herbicides 291 15. Lipid Biosynthesis Inhibitors 311 16. Inhibitors of Amino Acid Biosynthesis 326 17. Miscellaneous Herbicides 362 18. Herbicide Resistance in Crops and Weeds 379 III. PRACTICES 397 19. Small Grains and lax 399 20. ield Crops Grown in Rows 413 vii viii CONTENTS 21. Small-Seeded Legumes 443 22. Vegetable Crops 449 23. ruit and Nut Crops 484 24. Lawn, Turf, and Ornamentals 500 25. Pastures and Rangelands 522 26. Brush and Undesirable Tree Control 531 27. Aquatic Weed Control 546 28. Industrial Vegetation Management 564 29. Diagnosis of Herbicide Injury 573 30. Weed Science in the uture 592 APPENDIX 599 INDEX 649 PREACE Weeds affect everyone and should be of concern to all. The nature of weeds and how they interact with human activities form the basis of the discipline of weed science. Weeds may poison livestock or seriously slow their weight gain. They can cause allergic reactions in humans, such as hay fever and dermatitis. Weeds create problems in recreational areas such as golf courses, parks, and fishing and boating sites. They are troublesome in industrial areas, irrigation and drainage systems and along highways and railroads. In addition, crop yield and quality can be reduced by the competition and interference of weeds. Although weed science is an ever-expanding discipline, it has always involved an understanding of weed biology and ecology. Such knowledge is basic to designing effective and efficient methods of managing weeds and reducing their impact on human activities. Weed management is expensive and directly increases the price of food and fiber. It can also affect the environment, both beneficially and detrimentally. Bor example, various methods designed to manage weeds reduce crop loss and increase labor efficiency, but others, such as tillage, can increase soil erosion, and the use of herbicides must be constantly monitored to reduce or eliminate their effects on the environment and human health. Since 1940, there have been greater advances in the science of weed control than in all of its previous history. In this book, the old and reliable methods of weed control are integrated with newer techniques to design truly integrated multiple-factor weed management systems. The use of multitactic, fully integrated production practices results in more effective and less expensive weed control programs. These programs help reduce the cost of food and fiber production. Although this textbook places great emphasis on the chemical management of weeds, we realize that the discipline of weed science is rapidly moving toward reduced reliance on herbicides. This is a positive change; however, total elimination of herbicides for weed control in cropping systems will not happen in the near future, and herbicides will continue to play an important role in most weed management programs. This text has been written to provide the practitioner with important background information on all aspects of weed management. Informed practitioners know how best to use the available tools. They can determine the most effective, economical, and environmentally sound practices to maintain a sustainable agriculture in the twenty-first century and provide a reliable supply of food and fiber for the world. Designed mainly for college classroom instruction in the principles and practices of weed science, this fourth edition follows the format of previous editions but has been completely revised to provide more in-depth coverage of all topics. The detailed discussion of these topics also makes it useful to county agents, farm advisors, ix x PREBACE extension specialists, consultants, herbicide development personnel, research scientists, and farmers. The first third of the book deals with principles of weed science, the second third with herbicides, and the last third with weed control practices in specific crops or situations. Thus, this book brings together the modern philosophy of weed science and the techniques of weed control. In recent years weed scientists and the general public have become increasingly interested in the environmental impact and safety of the various methods of weed control, especially in regard to the use of herbicides. Such concern has led chemical companies to stress the development of new herbicides of low mammalian toxicity that can be used at very low rates. These products minimize environmental impact and maximize safe use. There has also been an increase in studies on the biology and ecology of weeds directed toward more effective control methods. An increased emphasis on such new directions is a feature of this fourth edition. Useful Web sites relating to and expanding on these topics are provided in each chapter. This fourth edition also provides more complete details on the use of herbicides than given in earlier editions. The sections on herbicide mechanism of action contain information useful to advanced students as well as undergraduates. It can provide a better understanding of how herbicides work and how they can be used more efficiently to control weeds. We hope that this will increase the value of this book to those using these chemicals in the field. However, nothing in this text is to be construed as recommending or authorizing the use of any weed control practice or chemical. A current manufacturers or suppliers label is the final word for the use of any herbicides, including method and time of application, rates at which a product is to be used, permissible crops or situations, weeds that can be controlled, and special precautions. Label recommendations must be followedregardless of any statements in this book. All long-term weed management systems will, by necessity, be part of an integrated approach as described herein. Herbicide usage is continually being revised. The Environmental Protection Agencys policy and the recent passage of the Bood Quality Protection Act require the re-registering of pesticides and increased testing related to health issues. Both this policy and the law are having a major impact on the registration of pesticides and their uses. There will be many changes in the availability and allowable uses of herbicides in the future; therefore, it is critical to check all current registrations before use and to employ a more holistic approach in weed management, with the use of multiple tactics. The common names of herbicides are generally used throughout the text. However, trade names and chemical names are also supplied. Trade names have been given as a convenience to the reader, not as an endorsement of any particular product. In addition to the text, the appendixes provide an assortment of information useful to students and weed control practitioners, including listings for herbicidal effectiveness for the control of many common weeds; commercially available herbicides cross-referenced by common name, trade name, and chemical manufacturer; conversion factors; herbicide concentration calculations; weight of dry soil, length of row required for one acre; mixing instructions for available commercial liquid and dry materials; and common cropland weeds in the United States.