In contrast to animals, plants are immobile and, thus, cannot leave a drastically changed environment. Therefore, plants have developped specific strategies involving particular signal and transduction systems as well as a form of cellular organization that allow them to buffer against sudden changes in external conditions. This state-of-the-art summary written by leading scientists deals with: - the most recent data available on the molecular mechanism involved in the response of plant cells to different stimuli; - the critical domaine of ignorance such as the signifi cance of site occupancy of receptors for growth substances; - the estimation of the applicability of new techniques such as electrophysiology, cell imaging and DNA recombinant technology; - directions for future work.

Environmental stresses, such as high and low temperature, salinity, and drought, represent limiting factors to agricultural productivity worldwide. Their impact is not only on crops that are presently being cultivated, but they are also significant barriers to the introduction of crop plants into noncultivated areas. The book describes the cellular, biochemical, and molecular mechanisms in plants that regulate tolerance to stresses. Also discussed are prospects of engineering stress-tolerant plants through the modification of germplasm.

The importance of irrigation in the world's agriculture is rapidly increasing. Although it is practised on a large scale mainly in arid and semi-arid zones, supplementary irrigation is becoming popular in semi-humid regions as well. The record of irrigation speaks for itself in terms of increased crop production. However, the question remains as to how permanent the achievement may be. Judging from history, it seems that irrigation eventually failed in many regions because the knowledge and technology available to society at the time were incapable of coping with the problems created. Undoubtedly soil salinity is the most prevalent and widespread problem limiting crop productivity in irrigated agriculture. It has, therefore, attracted the attention of the scientific community since the advent of modern agronomic research. Through the past six to seven decades a considerable body of information has been accumulated, which has promoted the understanding of the principles involved and helped to develop the technology for coping with the problems. Our present knowledge, if judiciously applied, is adequate for coping with many of the salinity problems resulting from mismanagement of irrigation and drainage. But for this knowledge to be used, it has to be generally known and understood and be re-examined from time to time.

Metal Speciation in the Environment is a multidiscipliary treatment of the occurrence, mobility and detection of metal compounds within different environments as well as their interaction with life. Special emphasis is given to the complexation of metals, to the state of the art of trace analytical methodology available for metal speciation (including atomic absorption spectrometry, plasma emission and mass spectrometry, neutron activation analysis, electrochemical methods, chemical sen- soring, a.o.), and environmental chemistry of elements such as the actinides and heavy metals (e.g. chromium, arsenic, tin, and copper).

This volume is dedicated to understanding the political economy obstacles to trade reform, especially global agricultural trade reform, and how these obstacles can be surmounted. The focus is on the trade reform under the GATT negotiations. New political-economic methodologies are used to assess and evaluate the obstacles and original scholarly analyses have been designed to explain why agriculture - among so many topics - became such a significant problem in the most recent Uruguay Round of the GATT.

This is a stimulating tale of the interplay of observation, experimentation, working hypotheses, tentative conclusions, niggling and weightier doubts and great aspirations, on the part of some score of students, on varied ecological and other aspects of the regime and role of fire in relevant biomes and ecosystem- mainly in South Africa - and on other pertinent features of fire ecology. The impressive contents is a tribute to conveners and authors alike. One can expect a profound range and depth ofinvestigation and interpretation, a closeknit fabric of knowledge, delicately interwoven with wisdom, an exposition and quintessence of information. Admipable is the collective vision responsible for selecting appropriate topics: the wide sweeps of the brush picturing the nature of the biomes; ably describing the fire regimes - whether in grassland, savanna, fynbos or forest; skillfully defining the effects of such regimes - according to ecosystem - upon aerial and edaphic factors of the habitat, upon constituent biota, individually, specifically and as a biotic community; elucidating the basic implications in the structure and dynamics of the plant aspect of that community ... and unravelling to some degree the tangled knot of the conservation and dissipation of moisture and nutrients. Moreover, gratitude is owed for efforts exerted to understand the interplay of fire and faunal behaviour and dynamics as well as composition, together with the principle of adaptive responses of organisms of diverse kinds.

Chemicals that control plant growth have long been treated like a poor re lation of the herbicides yet in one manner of thinking, herbicides them selves are but one facet of the entire picture of plant growth regulation - a major fraction, to be sure, economically. It is now time to recognize that plant growth regulators should occupy an increasingly important role in agriculture. Sufficient numbers of uses having considerable economic re turn have already become established: (a) to increase the latex flow in the rubber trees; (b) to ripen sugarcane; (c) to control sprouting in onions and potatoes; (d) to shorten and strengthen wheat stems to prevent lodging; (e) to prevent premature deterioration; and (f) to permit control of timing for maximum utilization of crops. In addition, as energy becomes more difficult and costly to obtain, plant growth regulators will play an increasingly important role in energy conser vation as a result of increased yields due to their use . . There are a number of ways to present to the reader the role and effec tiveness of plant growth regulators. The one chosen here is to emphasize the effects on plant functions such as the induction of roots, the control of flowering, the control of sex, and the control of aging. Little emphasis has been placed on the basic research that has served as a background for the successes and potential successes discussed herein. N or is much attention paid to the mode of action of the various regulators."

Presented here is a comprehensive account of both theoretical and practical aspects of sugarcane production. The first of two parts of the book deals with origin, distribution, soil and climatic requirements, seed bed preparation, cultural and nutrient requirements, fertilization, irrigation, ratooning, weeds, pests, diseases, ripening, and harvest. In thesecond part, energy and fibre cane, cane development, and manufacturing techniques of sugar and by-products are treated in detail. This book will serve as a vademecum for cane growers, sugar and sugarcane technologists, students and teachers.

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.

The information presented in this book is the result of combined research efforts of scientists at the University of Alaska, Fairbanks, the Institute of Northern Forestry, USDA Forest Service, and the Systems Ecology Research Group, San Diego State University. The objective of the volume is to present a synthetic overview of structure and function of taiga forest ecosystems in interior Alaska. The data base for this work has appeared in earlier published articles including the special issue of the Canadian Journal of Forest Research Volume 13:5 (1983). Stimulus for this book was a conference held in Fairbanks from June 10-14, 1983. The papers presented at the conference were fore runners of the chapters in this book. We invited 19 scientists from North America and England to critique our research and synthesis efforts. Six of these people were asked to write introductory chapters for each section of the book. Formal presentation sessions, combined with field trips to research sites, introduced the invitees to the primary and secondary successional ecosystems with which we were dealing. A major wildfire, only 24 km from the University campus, was contained the week prior to the conference and one field trip provided graphic evidence of fire impact in subarctic forests. The conference conveners regretted that it was not possible to host a similar meeting during synthesis efforts in mid-January."

With one volume each year, this review series keeps scientists and advanced students informed of the latest developments and results in all areas of the plant sciences.
Starting with this volume, the sections of PROGRESS IN BOTANY have been restructured. The new sections - Genetics - Cell Biology and Physiology - Systematics and Comparative Morphology - Ecology and Vegetation Science - correspond to the subdivision of the field of botany generally used by the scientific community.

Proceedings of the Physiology Working Group Technical Session Society of American Foresters National Convention, Portland, Oregon, USA, October 16-20, 1983

The Advanced Series in Agricultural Sciences is designed to ftll a long-felt need for advanced educational and technological books in the agricultural sciences. These texts, intended primarily for students of agriculture, should also provide up-to-date technical background reading for the many agricultural workers in extension services, educational systems, or international bodies. The editors of Advanced Series in Agricultural Sciences will select key subjects relating to the agricultural environment, agricultural physics and chemistry, soil science, plant sciences, animal sciences, food technology, and agricultural engineering for a critical and synthetic appraisal. An initial theoretical presentation will be used by authors of individual volumes in the series to develop a technical approach-including examples and practical solutions- to each subject. In addressing the advanced undergraduate and early graduate student of agriculture, selected authors will present the latest information, leavened with the lessons learned from their own experience, on precise and well-defined topics. Such books that widen the horizons of the student of agriculture can serve, too, as useful reference sources for the young specialist in the early years of his career. Many specialists who are involved in teaching agricultural science are isolated from universities and research institutions. This series will bring them up-to-date scientific information, thus keeping them in touch with progress. The basic objective of Advanced Series in Agricultural Sciences is to effect a structural integration of the theoretic and technical approaches to agriculture.

All meat has been grass. This statement of the old Greeks is still valid and thus plants contribute to the needs of a growing world popula tion. Their other key role for human life is reflected by their photosynthetic activity. Intensive agriculture reduces the carbon diox ide content of the atmosphere. The improvements of cultivated plants towards stable yields and desired quality characteristics are the sub jects of plant breeding. Here, an introductory picture of the present state of this topic in research and application is given. The senior author, H. Kuckuck, wrote the first edition in 1939 as a small German booklet, hence the nickname little cuckoo (Kuckuck = Engl. cuckoo). During the last 6 years (the fifth German edition appeared in 1985) again numerous results of basic research have found practical application, making extensive additions neces sary. Further, it seemed timely to change to the international language of science: English. For help in translation we are grateful to Silke Kluth and Kathy Seaman. Since agricultural sciences - like all others - have become more specialized, we were happy to welcome D. Baringer (Sect. 5.4), W. Hondelmann (Sects. 4.4, 4.5, and 6), V. Stoy (Sect. 4.2), and T. Thtlioglu (Sects. 2.3.1.4 and 3.5) as contributors to this edition. Finally, we would like to thank Springer-Verlag for all their efforts in helping to transform a small German booklet into a book available to a wider audience."

Plants, fungi, and viruses were among the first biological objects studied with an electron microscope. One of the two first instruments built by Siemens was used by Helmut Ruska, a brother of Ernst Ruska, the pioneer in constructing electron microscopes. H. Ruska published numerous papers on different biological objects in 1939. In one of these, the pictures by G. A. Kausche, E. Pfankuch, and H. Ruska of tobacco mosaic virus opened a new age in microscopy. The main problem was then as it still is today, to obtain an appropriate preparation of the specimen for observation in the electron microscope. Beam damage and specimen thickness were the first obstacles to be met. L. Marton in Brussels not only built his own instrument, but also made considerable progress in specimen preparation by introducing the impregnation of samples with heavy metals to obtain useful contrast. His pictures of the bird nest orchid root impregnated with osmium were revolutionary when published in 1934. It is not the place here to recall the different techniques which were developed in the subsequent years to attain the modern knowledge on the fine structure of plant cells and of different plant pathogens. The tremendous progress obtained with tobacco mosaic virus is reflected in the chapter by M. Wurtz on the fine structure of viruses in this Volume. New cytochemical and immunological techniques considerably surpass the morphological information obtained from the pathogens, especially at the host-parasite interface.

As a result of the green revolution, the use of yield-increasing inputs such as fer tilizer and pesticides became a matter of course in irrigated rice farming in Southeast Asia. Pesticides were applied liberally, both as a guarantee against crop failure and as a means of fully utilizing the existing yield potential of the crops. However, since outbreaks of pests, such as the brown planthopper (BPH) or the tungro virus, continued to occur despite the application of chemicals, a change of approach began to take place. It is now being realized more and more in Southeast Asia that crop protection problems cannot be resolved solely by the application of chemicals. In the past several years, increasing efforts have there fore been made to introduce, as a first step, supervised crop protection, leading gradually to integrated pest management (Kranz, 1982). Although the crop protection problems naturally differ in the different devel oping countries in Southeast Asia, the economic situation prevailing in these countries can nevertheless be regarded as an important common determinant: pesticide imports use up scarce foreign currency and thus compete with other imports essential to development. For the individual rice farmer, the problem is basically the same: his cash funds are limited and he must carefully weigh whether to use them for purchas ing pesticides, fertilizer or certified seed. In view of this constraint, it is becom ing necessary to abandon the purely prophylactic, routine calendar spraying and instead, employ critically timed and need-based pesticide applications."

These are the proceedings of an Advanced Research Workshop (ARW), sponsored by the NATO Science Panel, entitled "Pest Control: Operations and Systems Analysis in Fruit Fly Management." The ARW was held in Bad Windsheim, Germany during the week of 5 August 1985. The purpose of the ARW was to bring together scientists who are interested in fruit fly problems, but who usually do not have an opportunity to speak with each other, for an intense week of interdisciplinary collaboration. In particular, the group present at the ARW contained a mix of biologists, field ecologists, mathematical modellers, operational program managers, economists and social scientists. Each group has its own professional meetings at which fruit fly problems are discussed, but the point of the ARW was to learn about the problem from the perspective of other fields, which are equally important for the ultimate management of the fruit fly problems. (A list of attendees follows this preface. ) It appears that the ARW successfully met its objective of bringing together a group for interdisciplinary considerations of the problems; I hope that the proceedings do as well. The ARW was structured with formal lectures in the mornings and workshops in the afternoons. For the morning lectures, four different topics were chosen: 1) basic biology and ecology, 2) trapping and detection, 3) control and eradication, and 4) policy issues. Each morning, one lecture from each area was presented.

The world needs for food and fiber continue to increase. Population growth in the developing countries peaked at 2. 4 percent a year in 1965, and has fallen to about 2. 1 percent. However, in many developing countries almost half the people are under 15 years of age, poised to enter their productive and reproductive years. The challenges to produce enough food for this growing population will remain great. Even more challenging is growing the food in the areas of greatest need. Presently the world has great surpluses of food and fiber in some areas while there are devastating deficiencies in other areas. Economic conditions and the lack of suitable infrastructure for distribution all too often limit the alleviation of hunger even when there are adequate supplies, sometimes even within the country itself. World hunger can only be solved in the long run by increasing crop production in the areas where the population is growing most rapidly. This will require increased efforts of both the developed and developing countries. Much of the technology that is so successful for crop production in the developed countries cannot be utilized directly in the developing countries. Many of the principles, however, can and must be adapted to the conditions, both physical and economic, of the developing countries.

th st On June 20 and 21 1985 the third workshop on "Azospirillum: Geneties, Physiology, Eeology" took place at the University of Bayreuth, West Germany, organized by the geneties department. There were about 80 partieipants, who eame from German research institutions, from other European eountries, from India, Egypt, North and South America. The former workshops had taken place in Bayreuth too in 1981 and 1983 respeetively, henee the organizers eould draw on the experienees then obtained. Azospirilla have, during the past 12 years, found an ever inereasing seientifie interest, beeause first, these soil baeteria earry the genetie information for binding moleeular nitrogen from the air, and second, they live in elose vieinity to the roots of grain erops and forage grasses. By exploi tation of these two properties, it is hoped to develop inoeulation proeedures in soils poor in nitrogen. The reports on the first afternoon foeussed, as aresult of the Bayreuth research interest, on genetie approaehes.

Throughout the world natural forest ecosystems have been, and are being massively disrupted or destroyed. The boreal forests of Canada are no more immune to man's intervention than the tropical rain forests of Africa, and the day is rapidly approaching when natural forest ecosystems, undisturbed by man, will be found only as remnants in national parks and other protected areas. Yet where they continue to exist these ecosystems are an extraordinarily rich, though relatively neglected source of data that illuminate many aspects of the classic theory of evolution. The subject matter of this book is not, however, confined to natural forest ecosystems. Forest ecosystems under varying degrees of management, and man made forests are also a rich source of information on ecological genetics. In general, however, it can be said that the published evidence of this fact has not yet significantly penetrated the botanical literature. All too frequently it is confined to what might be termed forestry journals. It is hoped that this book will to some extent redress the balance, and draw attention to a body of published work which not only provides a basis for the rational management and conservation of forest ecosystems, but also complements the literature of ecological genetics and evolution. The first draft of Chapters I to V was written in German by the senior author and translated by E. K. MORGENSTERN of the Canadian Forestry Service."

This is the second of the set of three volumes in the Encyclopedia of Plant Physiology, New Series, that will cover the area of the hormonal regulation of plant growth and development. The overall plan for the set assumes that this area of plant physiology is sufficiently mature for a review of current knowl edge to be organized in terms of unifying principles and processes. Reviews in the past have generally treated each class of hormone individually, but this set of volumes is subdivided according to the properties common to all classes. Such an organization permits the examination of the hypothesis that differing classes of hormones, acting according to common principles, are determinants of processes and phases in plant development. Also in keeping with this theme, a plant hormone is defined as a compound with the properties held in common by the native members of the recognized classes of hormone. Current knowledge of the hormonal regulation of plant development is grouped so that the three volumes consider advancing levels of organizational complexity, viz: molecular and subcellular; cells, tissues, organs, and the plant as an organized whole; and the plant in relation to its environment."

Rhizobia are bacteria which inhabit the roots of plants in the pea family and "fix" atmospheric nitrogen for plant growth. They are thus of enormous economic importance internationally and the subject of intense research interest. Handbook for Rhizobia is a monumental book of practical methods for working with these bacteria and their plant hosts. Topics include the general microbiological properties of rhizobia and their identification, their potential as symbionts, methods for inoculating rhizobia onto plants, and molecular genetics methods for Rhizobium in the laboratory. The book will be invaluable to Rhizobium scientists, soil microbiologists, field and laboratory researchers at agricultural research centers, agronomists, and crop scientists.

Low temperature represents, together with drought and salt stress, one of the most important environmental constraints limiting the pro ductivity and the distribution of plants on the Earth. Winter survival, in particular, is a highly complex phenomenon, with regards to both stress factors and stress responses. The danger from winter cold is the result not only of its primary effect, i. e. the formation of ice in plant tissues; additional threats are presented by the freezing of water in and on the ground and by the load and duration ofthe snow cover. In recent years, a number of books and reviews on the subject of chilling and frost resistance in plants have appeared: all of these publications, however, concentrate principally on the mechanisms of injury and resistance to freezing at the cellular or molecular level. We are convinced that analysis of the ultrastructural and biochemical alterations in the cell and particularly in the plasma membrane during freezing is the key to understanding the limits of frost resistance and the mechanisms of cold acclimation. This is undoubtedly the immediate task facing those of us engaged in resistance research. It is nevertheless our opinion that, in addition to understanding the basic physiological events, we should be careful not to overlook the importance of the comparative aspects of the freezing processes, the components of stress avoidance and tolerance and the specific levels of resistance."