Some Other IUPAC Titles of Interest from Pergamon Press IUPAC Symposium Series BENOIT & REMPP: Macromolecules BRITTON & GOODWIN: Carotenoid Chemistry and Biochemistry BROWN & DA VIES: Organ-Directed Toxicity — Chemical Indices and Mechanisms CIARDELLI & GIUSTI: Structural Order in Polymers FREIDLINA & SKOROVA: Organic Sulfur Chemistry LAIDLER: Frontiers of Chemistry (Proceedings of the 28th IUPAC Congress) NOZAKI: Current Trends in Organic Synthesis ST-PIERRE & BROWN: Future Sources of Organic Raw Materials (CHEMRAWN I) SHEMILT: Chemistry & World Food Supplies (CHEMRAWN II) STEC: Phosphorus Chemistry Directed Towards Biology TROST & HUTCHINSON: Organic Synthesis — Today and Tomorrow IUPAC Nomenclature Guides IRVING, FREISER & WEST: Compendium of Analytical Nomenclature IUPAC: Nomenclature of Inorganic Chemistry & How to Name an Inorganic Substance (2-part set) RIGAUDY & KLESNEY: Nomenclature of Organic Chemistry WHIFFEN: Manual of Symbols & Terminology for Physicochemical Quantities and Units Journals CHEMISTRY INTERNATIONAL — IUPAC's international news magazine. PURE AND APPLIED CHEMISTRY — IUPAC's official journal, featuring proceedings of IUPAC conferences, nomenclature rules and technical reports. INTERNATIONAL UNION OF PURE AND APPLIED CHEMISTRY (Applied Chemistry Division) PESTICIDE CHEMISTRY: HUMAN WELFARE AND THE ENVIRONMENT Proceedings of the 5th International Congress of Pesticide Chemistry, Kyoto, Japan, 29 August - 4 September 1982 Editors-in-Chief J. MIYAMOTO Pesticides Division, Sumitomo Chemical Co., Ltd. Takarazuka, Hyogo, Japan and P. C. KEARNEY Agricultura] Environmental Quality institute, US Department of Agriculture, Beltsville, Maryland, USA Volume 1 SYNTHESIS AND STRUCTURE-ACTIVITY RELATIONSHIPS Volume Editors P. DOYLE ICI Plant Protection Division, Bracknell, Berkshire, UK and T. FUJITA Department of Agricultural Chemistry, Kyoto University, Japan PERGAMON PRESS OXFORD • NEW YORK • TORONTO • SYDNEY • PARIS • FRANKFURT U.K. Pergamon Press Ltd., Headington Hill Hall, Oxford 0X3 OBW, England U.S.A. Pergamon Press Inc., Maxwell House, Fairview Park, Elmsford, New York 10523, U.S.A. CANADA Pergamon Press Canada Ltd., Suite 104, 150 Consumers Road, Willowdale, Ontario M2J1P9, Canada AUSTRALIA Pergamon Press (Aust.) Pty. Ltd., P.O. Box 544, Potts Point, N.S.W. 2011, Australia FRANCE Pergamon Press SARL, 24 rue des Ecoles, 75240 Paris, Cedex 05, France FEDERAL REPUBLIC Pergamon Press GmbH, Hammerweg 6, OF GERMANY D-6242 Kronberg-Taunus, Federal Republic of Germany Copyright © 1983 International Union of Pure and Applied Chemistry AJJ flights Reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means: electronic, electrostatic, magnetic tape, mechanical, photocopying, recording or otherwise, without permission in writing from the copyright holders. First edition 1983 Library of Congress Cataloging in Publication Data International IUPAC Congress of Pesticide Chemistry (5th: 1982: Kyoto, Japan) Pesticide chemistry, human welfare and the environ ment. (IUPAC symposium series) At head of title: International Union of Pure and Applied Chemistry. Applied Chemistry Division. Congress organized by The Science Council of Japan, Pesticide Science Society of Japan, and the Japan Plant Protection Association. Includes bibliographical references. 1. Pesticides—Congresses. I. Miyamoto, J. (Junshi) E. Kearney, P. C. (Philip C), 1932- III. International Union of Pure and Applied Chemistry. Applied Chemistry Division. IV. Nihon Gakujutsu Kaigi. V. Nihon Nóyaku Gakkai. VI. Nihon Shokubutsu Bóeki Kyókai. VII. Title. VIII. Series. [DNLM: 1. Pesticides—Congresses. 2. Pesticide—Residues— Congresses. 3. Toxicology—Congresses. 4. Pest control—Congresses. WA 240 P4738] SB950.93.I57 1982 632'.95 82-24602 British Library Cataloguing in Publication Data International Congress of Pesticide Chemistry: (5th: 1982: Kyoto) Pesticide chemistry. 1. Pesticides. Environmental aspects—Congresses I. Title II. Miyamoto, J. III. Keaney, P. C. IV. International Union of Pure and Applied Chemistry. Applied Chemistry Division 632'.95042 QH545.P4 ISBN 0 08 029219 4 (4 vol set) ISBN 0 08 029222 4 (volume 1) In order to make this volume available as economically and as rapidly as possible the authors' typescripts have been reproduced in their original forms. This method unfortunately has its typographical limitations but it is hoped that they in no way distract the reader. Printed in Great Britain by A. Wheaton & Co. Ltd., Exeter Organizing Committee Chairman: M. Nakajima Vice Chairman: H. Fukami Secretary Generai: T. Misato Members: T. Endo, M. Eto, T. Fujita, S. Goto, T. Hosotsuji, W. Iida, T. Iwata, A. Kawana, K. Koshimizu, N. Kurihara, S. Kuwatsuka, S. Matsunaka, T. Mitsui, J. Miyamoto, J. Mizutani, K. Munakata, M. Saito, T. Saito, N. Takahashi, S. Takahashi, T. Tanaka, M. Uchiyama, K. Ueki, T. Ueno, I. Yamamoto, K. Yamashita, K. Yasutomi Scientific Programme Committee Chairman: J. Miyamoto Vice Chairman: P. C. Kearney Members: P. Doyle, N. Drescher, T. Fujita, S. Goto, R. Greenhalgh, D. H. Hutson, S. Kuwatsuka, S. Matsunaka, S. D. Murphy, N. Takahashi Congress Organizers The Science Council of Japan Pesticide Science Society of Japan Japan Plant Protection Association INTERNATIONAL UNION OF PURE AND APPLIED CHEMISTRY IUPAC Secretariat: Bank Court Chambers, 2-3 Pound Way, Cowley Centre, Oxford 0X4 3YF, UK PREFACE The Fifth International Congress of Pesticide Chemistry, sponsored by the International Union of Pure and Applied Chemistry, and organized jointly by the National Science Council of Japan, Pesticide Science Society of Japan and Japan Plant Protection Association, was held at Kyoto International Conference Hall in Kyoto, Japan, 29 August - 4 September 1982. The opening of the Congress culminated four years of intensive planning by the Scientific Programme Committee, the Organizing Committee, and a host of internationally recognized scientists dedicated to pesticide chemistry. The main theme of the Congress, Human Welfare — Environment — Pesticides, was intended to encompass current research topics in pesticide chemistry, not only for increased agricultural production, but also for public health purposes. Xenobiotics other than pesticides were also included. One thousand, six hundred scientists from 55 countries attended the Congress. Two distinguished scientists, Professor Dr. K. H. BCichel, Bayer AG, Leverkusen, FRG, and Dr. I. J. Graham-Bryce, East Mailing Research Station, UK, presented plenary lectures dealing with political, economic and philosophical aspects of pesticide use, as well as future pesticide research for improving human welfare. A number of distinguished invitees also addressed the Congress participants, including the President of IUPAC, Professor S. Nagakura. Eight main topics were selected as the subjects of the Congress, either because of their timely nature or because the area needs critical review. They included: Synthesis of Pesticides and Growth Regulators; Chemical Structure and Biological Activity; Bioactive Natural Products: Chemistry, Biochemistry and Physiology; Biochemistry of Pests and Mode of Action of Pesticides (including Mechanism of Resistance and Phytotoxicity); Metabolism and Degradation of Pesticides and Xenobiotics; Toxicology of Pesticides and Xenobiotics; Pesticide Residues and Methodology; and Formulation Chemistry. Each main topic included one symposium and several poster-discussion sessions. Each symposium consisted of several invited presentations, providing the participants with current and provocative overviews on important aspects of the respective topics. Poster-discussion sessions constituted the main body of presentations to the Congress and were intended to cover a wide variety of areas. Each included a few invited papers in addition to the contributed papers. Invited scientists served as leaders during the follow-up discussion after the poster presentations. Overall the Congress was organized into 49 sessions under the eight main topics with 694 submitted papers, including 236 invited papers. In addition to the eight main topics encompassed by the Congress, three complementary symposia dealing with related subjects were held simultaneously, with 31 invited presentations: Pyrethroid Insecticides — Biological Activity, Mode of Action, Metabolism and Toxicology; Antibiotics for Agricultural Use; and Herbicides and Plant Growth Regulators for Rice Culture. The proceedings of the Congress, entitled Pesticide Chemistry: Human Welfare and the Environment, comprise four volumes containing over 250 invited papers presented at the symposia, complementary symposia, and poster-discussion sessions. Specifically, the contents are: Volume 1: plenary lectures, synthesis, structure-activity; Volume 2: natural products, complementary symposia; Volume 3: mode of action, metabolism and degradation, toxicology; and Volume 4: residue analysis, formulation chemistry. It is sincerely hoped, by this overview of the present status of chemical and biochemical pest control, that readers gain an appreciation of how pesticide science continues to contribute to human welfare. Junshi Miyamoto Philip C. Kearney PC 1 - A* IX POLITICAL, ECONOMIC AND PHILOSOPHICAL ASPECTS OF PESTICIDE USE FOR HUMAN WELFARE K. H. Biichel Bayer AG, 5090 Leverkusen, Federai Republic of Germany INTRODUCTION: I. PESTICIDES IN AGRICULTURE 1. At the farm level a) Loss prevention b) Farm economics as safeguarded by the use of insecticides, fungicides, herbicides, growth regulators and others 2. Agriculture and food policies a) Food supply b) Nonedible crops c) Aspects in regard of developing countries II. PUBLIC HEALTH SECTOR 1. Nutrition as a basis for human welfare 2 . Control of vector-borne diseases 3 . Clean food: Mycotoxins and other naturally occur ring food contaminants III. SAFETY ASPECTS 1. Safety in the manufacture and application of pesti cides 2. Safety of the food consumer 3. Environmental aspects a) Behaviour of pesticides in soil, including lea ching, microorganisms and soil invertebrates b) Effect of pesticides on plants and wildlife c) The ecosystem and the balance of nature IV, LEGAL ASPECTS 1. Pesticides regulation secured by existing legisla tion 2. The need for harmonization 3. Consequences of overregulation V. FORWARD EDGES IN CROP PROTECTION 1. Genetic engineering for better crops a) Plant resistance against pests, diseases and agroche- micals b) Improvement of plant productivity c) Influencing of wanted or unwanted plant ingre dients d) Influencing of plant growth properties 2. Renewable resources (biomass) a) Biomass for energy b) Raw materials from biomass 3. Conclusions: Agrochemicals in future crop protec tion 3 4 K. H. Büchel INTRODUCTION The problem of our days is not so much the oil crisis, the econo mic recession, the discussion on nuclear power, the conflict between different social systems or the armament race, but the real problem is to guarantee the nutrition of mankind. 400 to 500 millions of people in our world still suffer from hunger, and every year the world's population increases by about 80 million people. The task of our days is to improve the state of world nutrition (Ref. la). This can be achieved by a bundle of measures. One important tool are the agrochemicals and pesticides. The potential and actual influence of these substances, not only on agriculture but also on the socioeconomic conditions in both, the developed and the developing countries, is far-reaching. PESTICIDES IN AGRICULTURE At the farm level The original and main use of pesticides is the prevention of crop losses at the farm level. As a consequence of the spectacular successes achieved in this field, the importance of agrochemicals to farm economics in general became evident. By permitting the use of improved machinery, and less soil cultivation, the use of pesticides has enabled the net return on farm investment to be improved and stabilized. Today, therefore, crop protection is an integral part of modern farming. There are two aspects of special importance at the farm level a) The yield loss has to be kept below the so-called economic threshold. Since the investment per unit area is more or less a fixed sum, yield losses will, expressed otherwise, directly reduce the net income. If for example the profit in absence of any loss is 20 %, a 10 % loss would reduce the earnings by 50 %. A loss of more than 20 % would already be intolerable. (Ref. lb; Fig. 1). Fig. 1. b) Especially in the developed countries, manpower must be re placed by mechanization and the use of agrochemicals. This is demonstrated by the development of wages for agricultural workers, on the one hand, and prices for tractors and pesti cides, on the other hand, during the period 1970/71 to 1978/79, in the Federal Republic of Germany (Ref. 2). Figure 2 clearly shows the real background of the still increasing importance of herbicides in farm economics. The farmer has no other choice than to make use of easy to handle, relatively cheap, safe and effective chemicals instead of highly paid workers . Political, Economic and Philosophical Aspects of Pesticide Use 5 Fig. 2 However, not only this monetary consideration has contributed to the world-wide acceptance of herbicides in modern farming; many others have played a part. One of them is the non or minimum tillage farming method, which - in dry regions - con tributes to the conservation of the moisture in the soil, saves energy and reduces soil erosion. (Ref. 3). Mechanical harvesting of many crops, esspecially of cereals with combines, is possible only if the crops are essentially free of weeds. For combine harvesting the moisture content of the ears must be as low as suitable (Ref. 1). Weeds retain moisture in the crop. Herbicides, therefore, are sometimes essential to the fully efficient utilization of expensive machinery. If the crop has not to overcome any weed competition for wa ter, and mineral fertilizers, it can make nearly full use of its own genetic capacity. But still other problems can occur. One is that the crop is allowed to grow so dense that the microclimatic conditions, may favour the development of cer tain parasitic fungi, such as mildew and rust. Another side effect is that the weight of the ears in relation to the stalks may become so heavy that it causes lodging of the crop with all it's undesirable results. Finally, the well fed cereal crop may be attacked by sucking insects like aphids (Ref. 4). These examples show to what degree modern research permanently has to solve new problems. Figure 3 shows not only the huge differences in the yield per hectare of one of the world's most important crops, wheat, but also the magnitude of the world's food reserves if modern agriculture is applied (Ref. 5). Fig. 3 Fig. 4 6 K. H. Büchel Cereal diseases can now be effectively controlled by safe, economical, and ecologically favourable fungicides. The prob lem of lodging could be solved by growth regulators which im prove the stability of the stalk, and thus permitting better use of fertilizers. The control of aphids is no problem. So yield levels which would have appeared unbelievable only a few decades ago are possible. In addition, Fig. 4 shows, to what extent stabilization of yields, and therefore their cal- culability have become possible. Agriculture and food policies If a crop loss for the single farmer threatens his economic exi stence, crop losses on a world basis threaten the very existence, or survival, of millions of people. Figure 5 shows one of the most alarming developments that have occured since the beginning of the energy crisis. For several years the world production of cereals has been unable to keep up with consumption (Ref. 6); as a result, carry-over stocks are dwindling year by year. According to official statements of the USDA, the grain stocks of the world have dropped in 1981/82 to their lowest level since the Second World War. We have to realize that during the last five years the world's total output of cereals has exceeded consumption only by an amount sufficient for slightly more than four days. During the last two years, indeed there has been a deficit to about 70 million tonnes. The stocks are running down. Fig. 5 Fig. 6 In face of this situation it seems almost unbelievable that more than an estimated third of the world's total potential harvest is still being lost to insects, plant diseases and weed competition. Figure 6 shows some calculations of the FAO, as published until 1978, for five of the world's most important crops (Ref. 7). The total loss in rice growing is equivalent to the total rice production of Asia, excluding Japan and Thailand, in 1980. In wheat growing the loss is equivalent to the total production of Asia and Australia. Most of these losses could be prevented by application of the present-day know-how and the available pesti cides (Ref. 8). I would like to draw your attention to a resolu tion, passed at a meeting of several UN organizations and the World Bank in late 1981 (Ref. 9), which stated the following: "If Political, Economic and Philosophical Aspects of Pesticide Use 7 it were possible to reduce the crop losses by only 15 %, this would result in an additional production of 100 million metric tonnes of cereals. This would be equivalent to the food supply of nearly the same number of people." Expressed in cereal prices the equivalent is about 16 billion $, which is exactly the amount of money spent annually by the industrialized nations on aid to developing countries. These considerations are not, of course, restricted to edible crops. Many other agriculturally grown raw materials, such as natural fibres (e.g. cotton, hemp, sisal) and natural rubber, constitute the backbone of the national economies of the pro ducing countries and represent a high export value. Cotton, today, without chemical protection, would be an article of exclu sive luxury. The extent to which the cotton harvest is safe guarded by crop protection measures is demonstrated by Fig. 7. This shows how improved control methods in a Central American Country changed the situation of the whole cotton industry within only a few years, giving the crop a key position in the national economy (Ref. 10, 11). Since 1962 there were no major changes ir the cotton growing area of the country. Fig. 7 This leads directly to the question of the impact which pestici des have or could have on the economies of the countries of the Third World. We have to take into account that there are really two different problems. The first is the problem of producing sufficient food for increasing populations; the second is the need to make agricultural production an efficient part of the general economy of these countries. In terms of the direct food supply one has to make a distinction between so-called subsistance crops, the staple food crops, and the cash crops. In my view, there is no doubt about the key function of subsist ance crops - be they cassava (manioc) in some countries or several cultivars of millet in others or the wide range of local crops in several parts of the southern hemisphere. These plants are grown under conditions which keep them far below their genetic potential. To improve the food supply under the local conditions of different countries by optimizing the yield and nutritional value of these crops is undoubtedly one of the most urgent tasks for plant breeders and agricultural experts. Crop protection products will be needed to assist them. As regards staple foods like cereals or potatoes, rationalization in the developed countries has already reached levels that hardly can be achieved by the developing countries. It must be realized, that for the next few decades it will be possible to produce staple food crops more cheaply in the developed countries. There is no doubt that herbicides have contributed considerably to this situation and will continue to do so.