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Seed planning and policy for agricultural production
Book reviews (and somewhat unusual) feature of the IPM strategy being advocated, and dealing with matters that are seldom considered in detail by entomologists, it is of very considerable interest. One wonders whether the possibility of using this powerful sampling method as a part of the monitoring system has ever been considered. The chapter on physical methods reviews the possible use of exposures to altered temperatures and various kinds of radiation. It also deals with the use of physical barriers, in the form of wrapping materials, in the prevention of infestation. As already noted, useful elevated temperatures occur during tobacco processing: freezing is more commonly used for already manufactured products. In a book advocating an IPM strategy in which sanitation is intended to minimise or replace the use of conventional pesticides, the chapter on general insecticide use appears almost redundant. It reviews the many pesticides that have been employed but fails to adequately address either the very important problems that can arise in the movement and marketing of tobacco due to the presence of pesticide residues or the problem of possible tainting. The chapter on insect growth regulatorsdealsonlywith methoprene. While this is stated to be the only material of this type in current widespread use in the industry, there are (unlike the treatments in other chapters) no pointers to alternatives. Methoprene is applied in two ways. First, using very specialised machinery, it is blended into tobacco at the stemmery at rates of from 5 to 10 g active ingredient per 1000 kg tobacco to provide from two to four years of protection by preventing pest population increases. Secondly, and in this reviewer’s opinion much less wisely, it is applied on a monthly schedule as a fog ‘to maintain a 10 ppm methoprene concentration on the surface dust’ of stemmery and manufacturing premises. The chapter on fumigation mentions methyl bromide and controlled atmospheres but deals mainly, and very adequately, with the use of phosphine. The final chapter deals with eight somewhat contrived ‘case histories’ which are nevertheless very useful in bringing together the IPM strategy advocated and in illustrating the way in which a knowledge of pest biology can assist in tracking down the site at which an infestation, that was detected further down the line, actually occurred. For warehouse personnel the book achieves its aim of providing a manual of infestation control. For those concerned with on-farm infestation protection, it will need to be supplemented with additional material but will nevertheless provide a valuable review of techniques that may already apply, or that may prove adaptable to, that situ-
ation. For those concerned with commodities other than tobacco, or with small-scale peasant production, it will provide a fascinating glimpse of an IPM strategy developed by an acutely quality conscious industry in a situation in which access to the commodity is under human control to a unique degree and in which biological pest-control methods do not figure at all. Museum workers concerned with the protection of their specimens as well as the people who come into contact with them will also find much that is relevant. C. B. Cottrell Tobacco Research Board Zimbabwe
Seed Planning and Policy for Agricultural Production by A. Fenwick Kelly (1994).
John Wiley. ISBN 0 471 95256 7. (Previously published by Belhaven Press in 1989). Price f16.95. To feed an increasing world population, food production must continue to improve, and much of this will depend on new and improved varieties of crops preferably with resistance to at least some pests and diseases. This book emphasises the vital importance of good seed supplies and discusses the roles of government, private enterprise and the seed grower, pointing out the need for their cooperation to ensure continuity of seed supplies. The text is followed by a very informative Appendix which describes the basic concepts and terms used in seed technology and classification. The author does not have a section on seed treatment although this is one aspect of importance in crop protection. The book is mainly aimed at agricultural administrators but is a useful reference for all those who are concerned with the supply of good quality seeds. G. A. Matthews
DDT in the Tropics: The Impact on Wildlife in Zimbabwe of GroundSpraying for Tsetse Fly Control. Eds
R. J. Douthwaite and C. C. D. Tingle. NRI, Chatham, pb 195 pp. Price f20.00. This well produced book provides a wealth of information concerning the effects of DDT on a whole range of animal species. The book as a whole is excellently produced, well illustrated and nicely laid out. There is also a beautiful series of colour plates illustrating some of the species studied. The book is divided into two sections: Part 1, an environmental statement and Part 2, the scientific report. The environmental statement gives an overview of the problem and clearly and concisely
describes the background to the problem, the study areas, the methods used and concludes with a list of the publications arising from the project in addition to a useful reference list. This section of the book will be invaluable to those involved in policy planning and implementation. The second part of the book is the scientific report detailing studies carried out in Zimbabwe from 1987 to 1991. This comprises 12 chapters written either singly or in collaboration, by experts in their various fields. The first chapter by Grant, deals with the deposition and dissipation of DDT and is followed by a chapter by the same author covering the critical soil processes involved. Chapters 3, 4, 5, 6, 7 and 8, deal with the effects of DDT on the wildlife in the area and cover, terrestrial invertebrates (Tingle), lizards (Lambert), woodland birds (Douthwaite), nocturnal animals (McWilliam), fish (McCarton & Mhlanga) and waterbirds (Douthwaite). Each chapter is competently and clearly writtenandsummarisesthemethodology and the results obtained. In addition. each chapter is illustrated with black and white prints and line drawings. It is all very clear and informative. The four concluding chapters arc grouped together under the heading Other Effects. These chapters deal with the risks to human health (Goll and McCarton), economic assessment (Abelson), the international dimension (Goll) and a final chapter discussing the future role of the synthetic pyrethroid deltamethrin as a replacement for DDT. One of the very nice things about this book is the very effective use of Boxes to cover in detail the experimental techniques and results. This enables the reader to read each chapter as a narrative, but to have the full details of any particular point easily to hand for reference or clarification. It is a device that could be used to some advantage by otherpublications. Interestinglyenough, the results of this study indicate that the impact of DDT was lower than had been anticipated, particularly in terms of economics, and that elephant damage and human settlement had caused greater damage to the environment than had 28 years of DDT use. It was also concluded that the effects of the DDTspraying were reversible in perhaps as little as 10-20 years. For anyone interested in DDT and its effects this is an excellent read. It also serves as an example as how the results of a scientific study can bc brought together in a widely accessible form. This book will provide a useful rcfercncc guide to a range of environmental scientists as well as being something that non experts can USCto gain information concerning avery important subject.
Crop Protection
Simon R. Leather
7996 Volume 15 Number 1
107
ation. For those concerned with commodities other than tobacco, or with small-scale peasant production, it will provide a fascinating glimpse of an IPM strategy developed by an acutely quality conscious industry in a situation in which access to the commodity is under human control to a unique degree and in which biological pest-control methods do not figure at all. Museum workers concerned with the protection of their specimens as well as the people who come into contact with them will also find much that is relevant. C. B. Cottrell Tobacco Research Board Zimbabwe
Seed Planning and Policy for Agricultural Production by A. Fenwick Kelly (1994).
John Wiley. ISBN 0 471 95256 7. (Previously published by Belhaven Press in 1989). Price f16.95. To feed an increasing world population, food production must continue to improve, and much of this will depend on new and improved varieties of crops preferably with resistance to at least some pests and diseases. This book emphasises the vital importance of good seed supplies and discusses the roles of government, private enterprise and the seed grower, pointing out the need for their cooperation to ensure continuity of seed supplies. The text is followed by a very informative Appendix which describes the basic concepts and terms used in seed technology and classification. The author does not have a section on seed treatment although this is one aspect of importance in crop protection. The book is mainly aimed at agricultural administrators but is a useful reference for all those who are concerned with the supply of good quality seeds. G. A. Matthews
DDT in the Tropics: The Impact on Wildlife in Zimbabwe of GroundSpraying for Tsetse Fly Control. Eds
R. J. Douthwaite and C. C. D. Tingle. NRI, Chatham, pb 195 pp. Price f20.00. This well produced book provides a wealth of information concerning the effects of DDT on a whole range of animal species. The book as a whole is excellently produced, well illustrated and nicely laid out. There is also a beautiful series of colour plates illustrating some of the species studied. The book is divided into two sections: Part 1, an environmental statement and Part 2, the scientific report. The environmental statement gives an overview of the problem and clearly and concisely
describes the background to the problem, the study areas, the methods used and concludes with a list of the publications arising from the project in addition to a useful reference list. This section of the book will be invaluable to those involved in policy planning and implementation. The second part of the book is the scientific report detailing studies carried out in Zimbabwe from 1987 to 1991. This comprises 12 chapters written either singly or in collaboration, by experts in their various fields. The first chapter by Grant, deals with the deposition and dissipation of DDT and is followed by a chapter by the same author covering the critical soil processes involved. Chapters 3, 4, 5, 6, 7 and 8, deal with the effects of DDT on the wildlife in the area and cover, terrestrial invertebrates (Tingle), lizards (Lambert), woodland birds (Douthwaite), nocturnal animals (McWilliam), fish (McCarton & Mhlanga) and waterbirds (Douthwaite). Each chapter is competently and clearly writtenandsummarisesthemethodology and the results obtained. In addition. each chapter is illustrated with black and white prints and line drawings. It is all very clear and informative. The four concluding chapters arc grouped together under the heading Other Effects. These chapters deal with the risks to human health (Goll and McCarton), economic assessment (Abelson), the international dimension (Goll) and a final chapter discussing the future role of the synthetic pyrethroid deltamethrin as a replacement for DDT. One of the very nice things about this book is the very effective use of Boxes to cover in detail the experimental techniques and results. This enables the reader to read each chapter as a narrative, but to have the full details of any particular point easily to hand for reference or clarification. It is a device that could be used to some advantage by otherpublications. Interestinglyenough, the results of this study indicate that the impact of DDT was lower than had been anticipated, particularly in terms of economics, and that elephant damage and human settlement had caused greater damage to the environment than had 28 years of DDT use. It was also concluded that the effects of the DDTspraying were reversible in perhaps as little as 10-20 years. For anyone interested in DDT and its effects this is an excellent read. It also serves as an example as how the results of a scientific study can bc brought together in a widely accessible form. This book will provide a useful rcfercncc guide to a range of environmental scientists as well as being something that non experts can USCto gain information concerning avery important subject.
Crop Protection
Simon R. Leather
7996 Volume 15 Number 1
107