Biochemistry And Physiology Of Herbicide Action

Herbicides are part of modern agricultural production systems and therefore contribute significantly to the economy of agricultural products. At the same time, herbicides are potent and specific inhibitors of plant metabolism and may therefore be used as valuable tools in basic plant physiological research. A well-known example is the photosynthesis-inhibiting herbicide diuron, known to plant physiologists as DCMU, which has become one of the essentials in modern photosynthesis research. Similarly, knowledge in other areas of plant metabolism may be advanced by the use of herbicides as specific inhibitors. This book describes the effects of herbicides on the metabolism of higher plants from the viewpoint of the plant physiologist. The material of this book is therefore, as far as possible, divided into areas of metabolism. This book intends (1) to present the reader with current knowledge and views in the area of herbicide modes of action and (2) to promote the future use of herbicides as metabolic inhibitors in plant physiological research to the advantage of both, the pesticide and the plant sciences. I wish to express my thanks to my colleagues and friends Prof. N. Amrhein, Prof. E. Elstner, Dr. L. Eue, Dr. J. Konze, Dr. K. Liirssen, Dr. W.Oettmeier, Dr. H. Quader, Dr. R. R. Schmidt, Dr. R. H. Shimabukuro, Dr. J. Stetter, Prof.

An introduction to herbicide action; Reaching the target; Oxigen toxicity and herbicidal action; Microtubule disruptors; Herbicide effects on lipid synthesis; Nucleic acid and protein synthesis inhibitors; Inhibition of amino acid biosysnthesis; Herbicides with auxin activity; Other sites of herbicide action; Secondary physiological effects of herbicides; Herbicide interactions with herbicides, synergists, and safeners; Naturally occurring chemicals as herbicides.

Herbicides make a spectacular contribution to modern crop production. Yet, for the development of more effective and safer agrochemicals, it is essential to understand how these compounds work in plants and their surroundings. This expanded and fully revised second edition of Herbicides and Plant Physiology provides a comprehensive and up-to-date account of how modern herbicides interact with target plants, and how they are used to manage crop production. In addition, the text: Provides a current account of the importance of weeds to crop yield and quality; Describes how new herbicides are discovered and developed; Examines precise sites of herbicide action and mechanisms of herbicide selectivity and resistance; Reviews commercial and biotechnological applications, including genetically engineered herbicide resistance in crops; Suggests new areas for future herbicide development; Includes many specially prepared illustrations. As a summary of diverse research information, this second edition of Herbicides and Plant Physiology is a valuable reference for students and researchers in plant physiology, crop production/protection, plant biochemistry, biotechnology and agriculture. All libraries in universities, agricultural colleges and research establishments where these subjects are studied and taught will need copies of this excellent book on their shelves.

Because plants of different species vary in the way in which they take up, transport, and metabolize chemicals in the soil, selective herbicides can be synthesized. This book examines those aspects of plant physiology, principally in crop plants, which can be affected by herbicides; the possibilities that are offered by recombinant DNA technology for developing resistance to herbicides; and methods for exploiting or preventing acquired tolerance. The author also covers recent work on ultra-selective mycoherbicides and the use of allelochemicals as herbicide substitutes.

Volume 2 deals with the mechanisms of herbicide action and of resistance and tolerance to herbicides. The first five chapters of this volume cover the effects of herbicides and adjuvants on the physiology of plants. Professor Black‘s chapter begins by covering the effects of herbicides on photosynthesis, including photosynthetic assimilation of nitrogen, sulfur, and phosphorus. This is followed by Dr. Morelands chapter on herbicide interactions with plant respiration. The third chapter by Professor Bartels deals with the effects of herbicides on chloroplast and cellular development with emphasis on correlating physiological information with ultrasound effects.

The classification of herbicides and types of toxicity; Determination of herbicides and plant growth regulators; Herbicide behaviour in the plant; Herbicide behaviour in the soil; Herbicide behaviour in the soil; Growth responses to herbicides; Morphogenetic effects of herbicides; Abscission responses to herbicides; Effects of herbicides on plant composition and metabolism; Responses of plants to sublethal concentration of 2,4-D, without and with added minerals; The effects of herbicides on endogenous regulator systems; The effects of herbicides on biophysical processes in the plant; Suscepltibility: factors in the plant modifyng the of given species to treatment; Herbicide selectivity in relation to formulation and application methods; The behaviour of herbicides in the plant in relation to selectivity; The design of herbicides.

A review of the most important areas of the biochemistry of herbicide action. The introductory chapter begins with the field of herbicide discovery, followed by chapters dealing with the herbicidal inhibition of photosynthesis, carotenoid biosynthesis, lipid biosynthesis, and amino acid biosynthesis. The metabolism of herbicides is discussed with particular reference to the formation of toxic components from non-toxic chemicals, and also the inactivation of toxic chemicals as a basis for selectivity. The final chapters are concerned with mechanisms of herbicide resistance in plants and the possibility of transferring resistance to susceptible crops. A glossary of the most important herbicidal chemicals mentioned in the text is included.

The development of chemicals to selectively control the growth of weeds has been a fascinating success story which has unfolded largely during the last four decades. The dramatic growth of herbicide research that followed the wartime discoveries of the auxin-type herbicides (phenoxyalkanoic acids) resulted in a whole range of compounds and mixtures which are used to eliminate broad-or narrow-leaved weeds from agricultural, horticul tural, or forestry crops. Today, the safe use of this armament of compounds requires our understanding of their mode of action, metabolism, and environmental persistence. The most recently developed herbicides are highly effective inhibitors of specific enzyme systems, and formulation may be an important factor determining their efficient delivery at specific target sites. In this book, the major target sites of herbicide action are discussed in Chapters 1-5, with particular reference to photosynthesis; amino acid, lipid, and carotenoid synthesis; and other primary target sites. The effects of synergists or antagonists as modifiers of herbicide action are described in Chapter 6. The importance of efficient target site delivery as a fundamental factor in herbicide activity and selectivity is generally recognized. Delivery of a potentially lethal dose of active ingredient may depend on a whole range of factors including the efficiency of application, retention, absorption, translocation, immobilization, and detoxification. These aspects are con sidered in the remaining chapters, with particular reference to the pathways and mechanisms involved in the uptake, translocation, and metabolism of soil-and foliage-applied herbicides.