- Email: [email protected]
Breeding fodder crops for marginal conditions
187
Book Reviews
easily do so. However, the topics are very accessible to scientists in areas such as agronomy and plant breeding, which are outside of traditional pest management specialties, as well as to advanced undergraduate and graduate students. The editors suggest that growers and those interested in environmental health will also be interested. Most of the chapters address topics related to plant pathogens and diseases. The four chapters related to insect pest topics discuss the use of natural enemies in combination with pesticides, biopesticides, baculoviruses as microbial pesticides, and insect biocontrol agents in greenhouse production. A single chapter considers the use of fungal agents for biological control of weeds. The remaining eleven chapters cover topics related to plant diseases. Three chapters emphasize improvements in disease resistance from advances in molecular and cellular biology by identification of molecular markers and specific resistance genes as well as the use of somatic hybridization techniques for gene transfer between species. Progress in some of these areas is so rapid that some of the information is already outdated, but the value of these chapters lies in their explanation of the concepts that have arisen from the research. They will prepare readers to appreciate the most recent progress that has occurred since the publication of this book. The other chapters related to the management of plant pathogens are varied. Several address how an improved understanding of host-parasite interactions at the molecular level may potentially lead to improved disease management. The specific topics addressed are interference in plant viral vector transmission, the relation of inducible preformed compounds to broad-spectrum plant disease resistance, and molecular strategies for biological control of fungal plant pathogens. The potential of induced resistance to pathogens is addressed in three different chapters, all from a different perspective. Rather than being repetitive, these treatments offer a variety of possible means to induce resistance and integrate it into disease management programs. Developing technologies for plant disease management are discussed in chapters on soil solarization, modifications of the sunlight spectrum in greenhouses, and practical approaches to the selection, production, and formulation of biocontrol agents.
In nearly all of the chapters, the authors have successfully presented the recent advances in their 'novel approach' in a way that should be readable by nearly anyone with a serious interest in agricultural production. The future success of these novel approaches depends on involvement of a broader group of people to find ways to incorporate them into practical crop management programs. An additional strength of the chapters are the thoughtful evaluations of the current limitations to the integration of the novel approaches into practical programs, where pesticide use will be difficult to eliminate, and what future research may solve these problems. Many of the authors emphasize the need for further funding both for continued development of these novel approaches and their integration into IPM programs. One small criticism applies to the few photographs that are so dark as to be almost useless as illustrations, but they are a small component of an otherwise well-edited book. The emphasis of topics in this book is certainly skewed towards plant disease aspects of IPM, and an argument could be made that the collection could be strengthened by focusing solely on that area. However, the insect- and weedrelated chapters are an interesting component of this overview book which is aimed at broader audiences and offer some interesting comparisons in approaches. Gail L. Schumann
Department of Plant Pathology University of Massachusetts 209 Fernald Hall Amherst, MA 01003-2420 USA
Breeding Fodder Crops Breeding Fodder Crops for Marginal Conditions. O.A. Rognli, E. Solberg and I. Schjeldrup (Editors). Proceedings of the 18th Eucarpia Fodder Crops Section Meeting, Loen, Norway, 25-28 August 1993. Kluwer Academic Publishers, Dordrecht, 1994. ISBN 0-7923-2948-1,329 pp., hardback, Dfl 210, US $30, UK £84. Marginal conditions are widespread in space a n d / o r time although their effects on agricultural
188
Book Reviews
output can vary considerably in different regions. They may occur rarely or may be a permanent feature of a great area (as in Northern Scandinavia or the Mediterranean Basin). Between these extremes are areas where marginal conditions are not uncommon but occur in a fairly unpredictable and random manner. Climate and soil factors have a primary role in creating marginal conditions, but land use policy is also important. Thus, the influence of environmental and social policies on, for example, grazing pressures, fertiliser inputs, irrigation use and industrial pollution can be critical in determining the agricultural value of marginal areas. Set-aside schemes may remove marginal land from agricultural production while reduced inputs, and lack of proper land management may expand areas of marginal status. Decisions on whether to initiate breeding programmes for marginal conditions are often also markedly influenced by seed marketing prospects. Therefore economical considerations are more often likely to influence decisions on breeding for marginal conditions than are biological limitations.
Breeding Fodder Crops for Marginal Conditions is Volume 2 of the Developments in Plant Breeding Series and reports on five sessions with 26 scientific papers and three workshops of this meeting. The first plenary paper is about 'Norwegian Plant Production and Its Challenges' by M. Stubsjoen. The greatest part of the book presents the outcome of specific research activities in the range of environmental conditions from Sardinia to Nordic countries. Several short reviews include 'Adaptation, Variation and Selection in Marginal Areas' by P.M.A. Tigerstedt; 'Some Consequences of Adaptation to Extreme Environments' by Tom McNeilly; 'Collecting and Evaluating Genetic Resources of Fodder Plants from Subalpine and Alpine Permanent Grassland' by Uwe Simon; 'Specific Adaptation and Breeding for Marginal Conditions' by Salvatore Ceccarelli; and 'Cooperative Breeding for the Northern Marginal Areas' by ,~slaug Helgad6ttir and H61mgeir Bj6rnsson. The research papers cover various aspects of breeding activities for marginal areas. In addition, there is a mixed bag of short presentations ranging from promising research findings to little more than progress reports. The book concludes with the reports of the three workshops devoted to breeding strategies for marginal areas and to the question: Can
high quality and adaptation to stress environments be combined? The papers follow a reasonably logical sequence through the five session categories: general aspects of adaptation to marginal conditions; collection and evaluation of plant populations for forage production; adaptation and breeding of forage crops; morphological and physiological aspects of breeding; genetic and genomic aspects of adaptation. I particularly enjoyed the two papers on general aspects of adaptation to marginal conditions. The contribution by Tigerstedt reviews the term adaptation and its derivatives as well as the characteristics of environmental marginality. Plant traits are discussed in relation to their adaptive significance, pointing out their phenotypic expression under stress. Tigerstedt concludes that natural selection is of significance in marginal areas, a fact that should be duly recognised in modern plant breeding programmes aiming at maximum stability but not necessarily maximum yield. Tom McNeilly presented a brief account illustrating what natural selection can achieve in response to extreme environmental factors and suggested that genetically based fixed responses to such selection can be substituted, at least in some situations, by phenotypically plastic responses. Restricted genetic variation of perennial ryegrass within indigenous plant material in Norway seems to be responsible for the slow breeding progress. To increase the variation in the ryegrass germplasm, Solberg et al. tested populations of diverse origin and adaptation. Salvatore Ceccarelli from ICARDA discusses evidence showing that the use of breeding principles developed for, and successfully applied, in favourable environments may be the main reason for the lack of breeding progress in marginal environments. He points out that with a typical crop of marginal and unpredictable environments, such as barley, it is possible to exploit genetic differences for specific adaptation to marginal environments under farmers' conditions and improve yield without additional inputs. Breeding for specific adaptation not only offers a solution on how to improve agricultural production in marginal environments, but can do so in a sustainable way both in relation to environmental impact and genetic diversity. Modern developments in plant breeding like marker assisted selection offer a new horizon to
Book Reviews
breeding for adaptation. Genes may be more readily transferred across species with the help of new technologies. Since this meeting, forage plant biotechnology has made great progress; the newest information is therefore not available in proceedings that are published with a delay of two years. However, the other information in the book that is of great relevance to marginal conditions has a longer half-life. It is a book with many good ideas but also with contributions that would not be able to compete in the harsh world of refereed journals. JosefN~sberger lnstitu~ of Plant Sciences Swiss Federal lnstitu~ of Technology Universit~trasse 2 8092 Zurich Swi~erland
Nitrogen Fertilization Nitrogen Fertilization in the Environment. P.E. Bacon (Editor). Marcel Dekker, New York, 1995. ISBN 0-8247-8994-6, 608 pp., hardback, US $185.00.
World use of nitrogen fertilizers to aid food production has increased at a phenomenal rate during the past 30 years, and there is international concern about the potential effect of this increase on environmental quality and public health. In his preface to this book, the editor notes that the balance between supplying sufficient nitrogen for optimal plant performance and minimizing pollution from excessive nitrogen application is delicate and dynamic and that the contributors to the book have prepared their chapters with the need for this balance in mind. The key role of the book is to advocate nitrogen fertilization in an environmentally responsible way. The book has 15 chapters, all reviews, ranging in length from 18 to 68 pages and in number of references from 27 to 250. The overall coverage of the relevant literature is substantial, and it extends up to 1994. The chapters, in order, deal with 'World Nitrogen Supply and Demand' (Bumb), 'Plant Uptake and Utilization of Nitrogen' (Engels and Marschner), 'Developments in Modeling Nitrogen Transformations in Soil' (Hansen, Shaffer, and Jensen), 'Model-
189
ing N Fertilization Requirements for Crops and Pastures' (Angus), 'Nitrogen Fertilization of Upland Crops' (Strong), 'Nitrogen Fertilization Practices of Lowland Rice Culture' (Mikkelsen, Jayaweera, and Rolston), 'Nitrogen Management and Fertilization of Tropical Plantation Tree Crops' (Chew and Pushparajah), 'Nitrogen Management for Intensively Grown Arable Crops and Field Vegetables' (Neeteson), 'Nitrogen Management in Orchards' (Sanchez, Khemira, Sugar, and Righetti), 'Nitrogen Cycling in Grazing Systems' (Jarvis, Scholefield, and Pain), 'Nitrogen Fertilization Practices in Forestry' (Binkley, Carter, and Allen), 'Atmospheric N 2 Fixation as an Alternative N Source' (Ledgard and Giller), 'Organic Wastes as Alternative Nitrogen Sources' (Sims), 'Modeling the Effects of Management Practices on Nitrogen in Soils and Groundwater' (Styczen and Storm), and 'Minimizing Gaseous Losses of Nitrogen' (Peoples, Mosier, and Freney). Twelve of the 32 authors of these chapters are based in the USA. The other 20 authors are from 10 different countries (Argentina, Australia, Canada, Denmark, England, Germany, Malaysia, New Zealand, Netherlands, Thailand). The chapters are well prepared and well edited, and many of the authors are recognized as authorities in their fields. For me, the last four chapters (12-15) were of special interest. Chapters 12 and 13 examine the importance of atmospheric N 2 and organic wastes as nitrogen sources for crop production and explore the environmental implications of substituting these nitrogen sources for artificial fertilizers. Chapters 14 and 15 discuss the processes leading to losses of nitrogen from soils and methods of reducing these losses (including the use of urease and nitrification inhibitors). As noted in the editor's preface, the contributors to this book "show that, with improved understanding of such issues as correct application technology, source-sink relationships, and appropriate models, it is possible to achieve both efficient production and sound environmental management". This is a valuable book and it is highly recommended to anyone involved in research on nitrogen fertilization and environmental problems related to the use of nitrogen fertilizers. It provides up-to-date information about nitrogen fertilization practices around the world and should be of interest to soil and crop scientists, fertilizer specialists, agricultural
Book Reviews
easily do so. However, the topics are very accessible to scientists in areas such as agronomy and plant breeding, which are outside of traditional pest management specialties, as well as to advanced undergraduate and graduate students. The editors suggest that growers and those interested in environmental health will also be interested. Most of the chapters address topics related to plant pathogens and diseases. The four chapters related to insect pest topics discuss the use of natural enemies in combination with pesticides, biopesticides, baculoviruses as microbial pesticides, and insect biocontrol agents in greenhouse production. A single chapter considers the use of fungal agents for biological control of weeds. The remaining eleven chapters cover topics related to plant diseases. Three chapters emphasize improvements in disease resistance from advances in molecular and cellular biology by identification of molecular markers and specific resistance genes as well as the use of somatic hybridization techniques for gene transfer between species. Progress in some of these areas is so rapid that some of the information is already outdated, but the value of these chapters lies in their explanation of the concepts that have arisen from the research. They will prepare readers to appreciate the most recent progress that has occurred since the publication of this book. The other chapters related to the management of plant pathogens are varied. Several address how an improved understanding of host-parasite interactions at the molecular level may potentially lead to improved disease management. The specific topics addressed are interference in plant viral vector transmission, the relation of inducible preformed compounds to broad-spectrum plant disease resistance, and molecular strategies for biological control of fungal plant pathogens. The potential of induced resistance to pathogens is addressed in three different chapters, all from a different perspective. Rather than being repetitive, these treatments offer a variety of possible means to induce resistance and integrate it into disease management programs. Developing technologies for plant disease management are discussed in chapters on soil solarization, modifications of the sunlight spectrum in greenhouses, and practical approaches to the selection, production, and formulation of biocontrol agents.
In nearly all of the chapters, the authors have successfully presented the recent advances in their 'novel approach' in a way that should be readable by nearly anyone with a serious interest in agricultural production. The future success of these novel approaches depends on involvement of a broader group of people to find ways to incorporate them into practical crop management programs. An additional strength of the chapters are the thoughtful evaluations of the current limitations to the integration of the novel approaches into practical programs, where pesticide use will be difficult to eliminate, and what future research may solve these problems. Many of the authors emphasize the need for further funding both for continued development of these novel approaches and their integration into IPM programs. One small criticism applies to the few photographs that are so dark as to be almost useless as illustrations, but they are a small component of an otherwise well-edited book. The emphasis of topics in this book is certainly skewed towards plant disease aspects of IPM, and an argument could be made that the collection could be strengthened by focusing solely on that area. However, the insect- and weedrelated chapters are an interesting component of this overview book which is aimed at broader audiences and offer some interesting comparisons in approaches. Gail L. Schumann
Department of Plant Pathology University of Massachusetts 209 Fernald Hall Amherst, MA 01003-2420 USA
Breeding Fodder Crops Breeding Fodder Crops for Marginal Conditions. O.A. Rognli, E. Solberg and I. Schjeldrup (Editors). Proceedings of the 18th Eucarpia Fodder Crops Section Meeting, Loen, Norway, 25-28 August 1993. Kluwer Academic Publishers, Dordrecht, 1994. ISBN 0-7923-2948-1,329 pp., hardback, Dfl 210, US $30, UK £84. Marginal conditions are widespread in space a n d / o r time although their effects on agricultural
188
Book Reviews
output can vary considerably in different regions. They may occur rarely or may be a permanent feature of a great area (as in Northern Scandinavia or the Mediterranean Basin). Between these extremes are areas where marginal conditions are not uncommon but occur in a fairly unpredictable and random manner. Climate and soil factors have a primary role in creating marginal conditions, but land use policy is also important. Thus, the influence of environmental and social policies on, for example, grazing pressures, fertiliser inputs, irrigation use and industrial pollution can be critical in determining the agricultural value of marginal areas. Set-aside schemes may remove marginal land from agricultural production while reduced inputs, and lack of proper land management may expand areas of marginal status. Decisions on whether to initiate breeding programmes for marginal conditions are often also markedly influenced by seed marketing prospects. Therefore economical considerations are more often likely to influence decisions on breeding for marginal conditions than are biological limitations.
Breeding Fodder Crops for Marginal Conditions is Volume 2 of the Developments in Plant Breeding Series and reports on five sessions with 26 scientific papers and three workshops of this meeting. The first plenary paper is about 'Norwegian Plant Production and Its Challenges' by M. Stubsjoen. The greatest part of the book presents the outcome of specific research activities in the range of environmental conditions from Sardinia to Nordic countries. Several short reviews include 'Adaptation, Variation and Selection in Marginal Areas' by P.M.A. Tigerstedt; 'Some Consequences of Adaptation to Extreme Environments' by Tom McNeilly; 'Collecting and Evaluating Genetic Resources of Fodder Plants from Subalpine and Alpine Permanent Grassland' by Uwe Simon; 'Specific Adaptation and Breeding for Marginal Conditions' by Salvatore Ceccarelli; and 'Cooperative Breeding for the Northern Marginal Areas' by ,~slaug Helgad6ttir and H61mgeir Bj6rnsson. The research papers cover various aspects of breeding activities for marginal areas. In addition, there is a mixed bag of short presentations ranging from promising research findings to little more than progress reports. The book concludes with the reports of the three workshops devoted to breeding strategies for marginal areas and to the question: Can
high quality and adaptation to stress environments be combined? The papers follow a reasonably logical sequence through the five session categories: general aspects of adaptation to marginal conditions; collection and evaluation of plant populations for forage production; adaptation and breeding of forage crops; morphological and physiological aspects of breeding; genetic and genomic aspects of adaptation. I particularly enjoyed the two papers on general aspects of adaptation to marginal conditions. The contribution by Tigerstedt reviews the term adaptation and its derivatives as well as the characteristics of environmental marginality. Plant traits are discussed in relation to their adaptive significance, pointing out their phenotypic expression under stress. Tigerstedt concludes that natural selection is of significance in marginal areas, a fact that should be duly recognised in modern plant breeding programmes aiming at maximum stability but not necessarily maximum yield. Tom McNeilly presented a brief account illustrating what natural selection can achieve in response to extreme environmental factors and suggested that genetically based fixed responses to such selection can be substituted, at least in some situations, by phenotypically plastic responses. Restricted genetic variation of perennial ryegrass within indigenous plant material in Norway seems to be responsible for the slow breeding progress. To increase the variation in the ryegrass germplasm, Solberg et al. tested populations of diverse origin and adaptation. Salvatore Ceccarelli from ICARDA discusses evidence showing that the use of breeding principles developed for, and successfully applied, in favourable environments may be the main reason for the lack of breeding progress in marginal environments. He points out that with a typical crop of marginal and unpredictable environments, such as barley, it is possible to exploit genetic differences for specific adaptation to marginal environments under farmers' conditions and improve yield without additional inputs. Breeding for specific adaptation not only offers a solution on how to improve agricultural production in marginal environments, but can do so in a sustainable way both in relation to environmental impact and genetic diversity. Modern developments in plant breeding like marker assisted selection offer a new horizon to
Book Reviews
breeding for adaptation. Genes may be more readily transferred across species with the help of new technologies. Since this meeting, forage plant biotechnology has made great progress; the newest information is therefore not available in proceedings that are published with a delay of two years. However, the other information in the book that is of great relevance to marginal conditions has a longer half-life. It is a book with many good ideas but also with contributions that would not be able to compete in the harsh world of refereed journals. JosefN~sberger lnstitu~ of Plant Sciences Swiss Federal lnstitu~ of Technology Universit~trasse 2 8092 Zurich Swi~erland
Nitrogen Fertilization Nitrogen Fertilization in the Environment. P.E. Bacon (Editor). Marcel Dekker, New York, 1995. ISBN 0-8247-8994-6, 608 pp., hardback, US $185.00.
World use of nitrogen fertilizers to aid food production has increased at a phenomenal rate during the past 30 years, and there is international concern about the potential effect of this increase on environmental quality and public health. In his preface to this book, the editor notes that the balance between supplying sufficient nitrogen for optimal plant performance and minimizing pollution from excessive nitrogen application is delicate and dynamic and that the contributors to the book have prepared their chapters with the need for this balance in mind. The key role of the book is to advocate nitrogen fertilization in an environmentally responsible way. The book has 15 chapters, all reviews, ranging in length from 18 to 68 pages and in number of references from 27 to 250. The overall coverage of the relevant literature is substantial, and it extends up to 1994. The chapters, in order, deal with 'World Nitrogen Supply and Demand' (Bumb), 'Plant Uptake and Utilization of Nitrogen' (Engels and Marschner), 'Developments in Modeling Nitrogen Transformations in Soil' (Hansen, Shaffer, and Jensen), 'Model-
189
ing N Fertilization Requirements for Crops and Pastures' (Angus), 'Nitrogen Fertilization of Upland Crops' (Strong), 'Nitrogen Fertilization Practices of Lowland Rice Culture' (Mikkelsen, Jayaweera, and Rolston), 'Nitrogen Management and Fertilization of Tropical Plantation Tree Crops' (Chew and Pushparajah), 'Nitrogen Management for Intensively Grown Arable Crops and Field Vegetables' (Neeteson), 'Nitrogen Management in Orchards' (Sanchez, Khemira, Sugar, and Righetti), 'Nitrogen Cycling in Grazing Systems' (Jarvis, Scholefield, and Pain), 'Nitrogen Fertilization Practices in Forestry' (Binkley, Carter, and Allen), 'Atmospheric N 2 Fixation as an Alternative N Source' (Ledgard and Giller), 'Organic Wastes as Alternative Nitrogen Sources' (Sims), 'Modeling the Effects of Management Practices on Nitrogen in Soils and Groundwater' (Styczen and Storm), and 'Minimizing Gaseous Losses of Nitrogen' (Peoples, Mosier, and Freney). Twelve of the 32 authors of these chapters are based in the USA. The other 20 authors are from 10 different countries (Argentina, Australia, Canada, Denmark, England, Germany, Malaysia, New Zealand, Netherlands, Thailand). The chapters are well prepared and well edited, and many of the authors are recognized as authorities in their fields. For me, the last four chapters (12-15) were of special interest. Chapters 12 and 13 examine the importance of atmospheric N 2 and organic wastes as nitrogen sources for crop production and explore the environmental implications of substituting these nitrogen sources for artificial fertilizers. Chapters 14 and 15 discuss the processes leading to losses of nitrogen from soils and methods of reducing these losses (including the use of urease and nitrification inhibitors). As noted in the editor's preface, the contributors to this book "show that, with improved understanding of such issues as correct application technology, source-sink relationships, and appropriate models, it is possible to achieve both efficient production and sound environmental management". This is a valuable book and it is highly recommended to anyone involved in research on nitrogen fertilization and environmental problems related to the use of nitrogen fertilizers. It provides up-to-date information about nitrogen fertilization practices around the world and should be of interest to soil and crop scientists, fertilizer specialists, agricultural