This two-volume book is a valuable resource to students, researchers, scientists, commercial producers, consultants and policymakers interested in agriculture or plant sciences particularly in date palm biotechnology. Date Palm Biotechnology Protocols, Volume 1: Tissue Culture and Applications is comprised of 27 chapters covering adventitious organogenesis, somatic embryogenesis, contamination, hyperhydricity, acclimatization, cell suspension, protoplast and bioreactors, genetic transformation secondary metabolites, and abiotic stress. Written in the highly successful Methods in Molecular Biology series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Authoritative and practical, Date Palm Biotechnology Protocols, Volume 1: Tissue Culture and Applications aims to supplement the previous volume and to provide precise stepwise protocols in the field of date palm biotechnology.

Genetic erosion is the loss of genetic diversity within a species. It can happen very quickly, due to catastrophic events, or changes in land use leading to habitat loss. But it can also occur more gradually and remain unnoticed for a long time. One of the main causes of genetic erosion is the replacement of local varieties by modern varieties. Other causes include environmental degradation, urbanization, and land clearing through deforestation and brush fires. In order to conserve biodiversity in plants, it is important to targets three independent levels that include ecosystems, species and genes. Genetic diversity is important to a species' fitness, long-term viability, and ability to adapt to changing environmental conditions. Chapters in this book are written by leading geneticists, molecular biologists and other specialists on relevant topics on genetic erosion and conservation genetic diversity in plants. This divisible set of two volumes deals with a broad spectrum of topics on genetic erosion, and approaches to biodiversity conservation in crop plants and trees. Volume 1 deals with indicators and prevention of genetic erosion, while volume 2 covers genetic diversity and erosion in a number of plants species. These two volumes will also be useful to botanists, biotechnologists, environmentalists, policy makers, conservationists, and NGOs working to manage genetic erosion and biodiversity.

Today, in a world with abundant food, more than 700 million people are chro- cally undernourished. Over the next 20 years, the world's population will probably double. The global food supply would need to double or to triple for the larger population to be fed adequately. Agriculture is closely linked to environmental quality in a variety of ways, and the challenge of our generation is how to feed a growing planet while maintaining the integrity of our ecological life-support system. The responsibility of governments for ensuring food security will grow proportionately with the growth of populations, and governments bear a special responsibility for promoting agricultural inputs. Agriculture in the 21st century, will certainly focus increasingly on adapting modern technologies to local farming systems, needs and environments. Worldwide climatic changes have been raising concerns about potential changes to crop yields and production systems. Such concerns include the ability to acc- modate these uncertain effects in order to ensure an adequate food supply for an increasing population. What can be done concretely to use agriculture to address some of the fundamental issues of today's world? We must recognize that agric- ture is part of the solution and not just a problem. Agricultural development is a key to social stability and equity in many parts of the world. It can help to al- viate the subtle and unspoken fears of modernization and the space of change if innovation is handled transparently.

Since the beginning of agricultural production, there has been a continuous effort to grow more and better quality food to feed ever increasing popula tions. Both improved cultural practices and improved crop plants have allowed us to divert more human resources to non-agricultural activities while still increasing agricultural production. Malthusian population predictions continue to alarm agricultural researchers, especially plant breeders, to seek new technologies that will continue to allow us to produce more and better food by fewer people on less land. Both improvement of existing cultivars and development of new high-yielding cultivars are common goals for breeders of all crops. In vitro haploid production is among the new technologies that show great promise toward the goal of increasing crop yields by making similar germplasm available for many crops that was used to implement one of the greatest plant breeding success stories of this century, i. e., the development of hybrid maize by crosses of inbred lines. One of the main applications of anther culture has been to produce diploid homozygous pure lines in a single generation, thus saving many generations of backcrossing to reach homozygosity by traditional means or in crops where self-pollination is not possible. Because doubled haploids are equivalent to inbred lines, their value has been appreciated by plant breeders for decades. The search for natural haploids and methods to induce them has been ongoing since the beginning of the 20th century."

Since the beginning of agricultural production, there has been a continuous effort to grow more and better quality food to feed ever increasing popula tions. Both improved cultural practices and improved crop plants have alIowed us to divert more human resources to non-agricultural activities while still increasing agricultural production. Malthusian population predictions continue to alarm agricultural researchers, especially plant breeders, to seek new technologies that will continue to allow us to produce more and better food by fewer people on less land. Both improvement of existing cultivars and development of new high-yielding cultivars are common goals for breeders of alI crops. In vitro haploid production is among the new technologies that show great promise toward the goal of increasing crop yields by making similar germplasm available for many crops that was used to implement one of the greatest plant breeding success stories of this century, i. e., the development of hybrid maize by crosses of inbred lines. One of the main applications of anther culture has been to produce diploid homozygous pure lines in a single generation, thus saving many generations of backcrossing to reach homozygosity by traditional means or in crops where self-pollination is not possible. Because doubled haploids are equivalent to inbred lines, their value has been appreciated by plant breeders for decades. The search for natural haploids and methods to induce them has been ongoing since the beginning of the 20th century."

Since the beginning of agricultural production, there has been a continuous effort to grow more and better quality food to feed ever increasing popula tions. Both improved cultural practices and improved crop plants have al lowed us to divert more human resources to non-agricultural activities while still increasing agricultural production. Malthusian population predictions continue to alarm agricultural researchers, especially plant breeders, to seek new technologies that will continue to allow us to produce more and better food by fewer people on less land. Both improvement of existing cultivars and development of new high-yielding cultivars are common goals for breeders of all crops. In vitro haploid production is among the new technologies that show great promise toward the goal of increasing crop yields by making similar germplasm available for many crops that was used to implement one of the greatest plant breeding success stories of this century, i. e., the development of hybrid maize by crosses of inbred lines. One of the main applications of anther culture has been to produce diploid homozygous pure lines in a single generation, thus saving many generations of backcrossing to reach homozygosity by traditional means or in crops where self-pollination is not possible. Because doubled haploids are equivalent to inbred lines, their value has been appreciated by plant breeders for decades. The search for natural haploids and methods to induce them has been ongoing since the beginning of the 20th century."

The 18 chapters making up In Vitro Haploid Production in Higher Plants are divided into two sections. Section 1 (eight chapters) covers historical and fundamental aspects of haploidy in crop improvement. Section 2 deals with methods of haploid production, including anther culture, micropore culture, ovary culture, pollination with irradiated pollen, in vitro pollination, and special culture techniques, including polyhaploid production in the Triticeae by sexual hybridization, the influence of ethylene and gelling agents on anther culture, conditional lethal markers, and methods of chromosome doubling.

Micropropagation has become a reliable and routine approach for large-scale rapid plant multiplication, which is based on plant cell, tissue and organ culture on well defined tissue culture media under aseptic conditions. A lot of research efforts are being made to develop and refine micropropagation methods and culture media for large-scale plant multiplication of several number of plant species. However, many forest and fruit tree species still remain recalcitrant to in vitro culture and require highly specific culture conditions for plant growth and development. The recent challenges on plant cell cycle regulation and the presented potential molecular mechanisms of recalcitrance are providing excellent background for understanding on totipotency and what is more development of micropropagation protocols. For large-scale in vitro plant production the important attributes are the quality, cost effectiveness, maintenance of genetic fidelity, and long-term storage. The need for appropriate in vitro plant regeneration methods for woody plants, including both forest and fruit trees, is still overwhelming in order to overcome problems facing micropropagation such as somaclonal variation, recalcitrant rooting, hyperhydricity, polyphenols, loss of material during hardening and quality of plant material. Moreover, micropropagation may be utilized, in basic research, in production of virus-free planting material, cryopreservation of endangered and elite woody species, applications in tree breeding and reforestation.

The quality of human life has been maintained and enhanced for generations by the use of trees and their products. In recent years, ever rising human population growth has put tremendous pressure on trees and tree products; growing awareness of the potential of previously unexploited tree resources and environmental pollution have both accelerated development of new technologies for tree propagation, breeding and improvement. Biotechnology of trees may be the answer to solve the problems which cannot be solved by conventional breeding methods. The combination of biotechnology and conventional methods such as plant propagation and breeding may be a novel approach to improving and multiplying in large number the trees and woody plants. So far, plant tissue culture technology has largely been exploited in the propagation of ornamental plants, especially foliage house plants, by com mercial companies. Generally, tissue culture of woody plants has been recal citrant. However, limited success has been achieved in tissue culture of angiosperm and gymnosperm woody plants. A number of recent reports on somatic embryogenesis in woody plants such as Norway spruce (Picea abies), Loblolly pine (Pinus taeda), Sandalwood (Santalurn album), Citrus, Mango (Mangifera indica), etc., offer a ray of hope of: a) inexpensive clonal propa gation for large-scale production of plants or "emblings" or "somatic embryo plants," b) protoplast work, c) cryopreservation, d) genetic transformation, and e) artificial or manufactured seed production."

The quality of human life has been maintained and enhanced for generations by the use of trees and their products. In recent years, ever rising human population growth has put tremendous pressure on trees and tree products; growing awareness of the potential of previously un exploited tree resources and environmental pollution have both accelerated development of new technologies for tree propagation, breeding and improvement. Biotechnology of trees may be the answer to solve the problems which cannot be solved by conventional breeding methods. The combination of biotechnology and conventional methods such as plant propagation and breeding may be a novel approach to improving and multiplying in large number the trees and woody plants. So far, plant tissue culture technology has largely been exploited in the propagation of ornamental plants, especially foliage house plants, by com- mercial companies. Generally, tissue culture of woody plants has been recal- citrant. However, limited success has been achieved in tissue culture of angiosperm and gymnosperm woody plants. A number of recent reports on somatic embryogenesis in woody plants such as Norway spruce (Picea abies), Loblolly pine (Pinus taeda), Sandalwood (Santalum album), Citrus, Mango (Mangifera indica), etc. offer a ray of hope of: (a) inexpensive clonal propa- gation for large-scale production of plants or "emblings" or "somatic embryo plants"; (b) protoplast work; (c) cryopreservation; (d) genetic transforma- tion; and (e) artificial or manufactured seed production.

This book is the first volume of a comprehensive assemblage of contemporary knowledge relevant to genomics and other omics in date palm. Volume 1 consists of 11 chapters arranged in 3 parts grouped according to subject. Part I, Biology and Phylogeny, focuses on date palm biology, evolution and origin. Part II, Biodiversity and Molecular Identification, covers conformity of in vitro derived plants, molecular markers, barcoding, pollinizer genetics and gender determination. Part III, Genome Mapping and Bioinformatics, addresses genome mapping of nuclear, chloroplast and mitochondrial DNA, in addition to a chapter on progress made in date palm bioinformatics. This volume represents the efforts of 30 international scientists from 10 countries and contains 78 figures and 30 tables to illustrate presented concepts. Volume 2 is published under the title: Omics and Molecular Breeding.

Cash crops are grown and sold for monetary gain and not necessarily for sustenance. They include coffee, tea, coconut, cotton, jute, groundnut, castor, linseed, cocoa, rubber, cassava, soybean, sweet potato, potato, wheat, corn and teff. While some of these crops have been improved for realizing yield potential, breeding of many of them is still in infancy. Crops that underwent rigorous breeding have eventually lost much of the diversity due to extensive cultivation with a few improved varieties and the diversity in less bred species is to be conserved. Over the past years, scholars and policy makers have become increasingly aware of the short and long-run impact of climatic factors on economic, food security, social and political outcomes . Genetic diversity, natural and induced, is much needed for the future generations to sustain food production with more climate resilient crops. In contrast, crop uniformity produced across the farm fields in the form of improved varieties is genetically vulnerable to biotic and abiotic stresses. Thus, it is essential and challenging to address the issue of compromising between maximizing crop yield under a given set of conditions and minimizing the risk of crop failure when conditions change. Cash crops are grown in an array of climatic conditions. Many of the world's poor still live in rural areas. Many are subsistence farmers, operating very small farms using very little agricultural inputs for achieving marketable outputs. Conserving the diversity of these crops and addressing all issues of crop culture through modern tools of biotechnology and genomics is a real challenge. We believe the focus of this book is to fill an unmet need of this and other grower communities by providing the necessary knowledge, albeit indirectly via the academics, to manage the risks of cash crops breeding through managing genetic diversity.

We can not talk about commodity production without building up all the operations after harvest. It is possible to market the products just after harvest, but it is only possible in small quantities. Postharvest handling is the ultimate stage in the process of producing quality fresh fruits and vegetables, getting these unique packages of water (fresh commodities) to the supper table. Fresh fruits and vegetables are succeptible to a number of postharvest disease and disorders and the postharvest operations are predominately aimed at maintaining harvest quality. Every step in the handling chain can influence the extent of disease and quality of the stored product. From planting to consumption, there are many opportu- ties for bacteria, viruses, and parasites to contaminate produce or nutrient deficiency level causing physiological disorders. Most of the storage rots are diseases that have originated in the field and have carried over onto commodities after harvest. Physiological disorders also arise from poor handling between harvest, storage and marketing. Treatments have a direct effect on inactivating or outright killing germinating spores, thus minimising rots. Prestorage treatment appears to be a promising method of postharvest control of decay. Pre-or-postharvest treatments of commodities are considered as potentiel alternatives for reducing the incidence of diseases, disorders, desinfestation of quarantine pests and for preserving food quality. Postharvest treatments lead to an alteration of gene expression and fruit ripening can sometimes be either delayed or disrupted.

Since the beginning of agricultural production, there has been a continuous effort to grow more and better quality food to feed ever increasing popula tions. Both improved cultural practices and improved crop plants have allowed us to divert more human resources to non-agricultural activities while still increasing agricultural production. Malthusian population predictions continue to alarm agricultural researchers, especially plant breeders, to seek new technologies that will continue to allow us to produce more and better food by fewer people on less land. Both improvement of existing cultivars and development of new high-yielding cultivars are common goals for breeders of all crops. In vitro haploid production is among the new technologies that show great promise toward the goal of increasing crop yields by making similar germplasm available for many crops that was used to implement one of the greatest plant breeding success stories of this century, i. e., the development of hybrid maize by crosses of inbred lines. One of the main applications of anther culture has been to produce diploid homozygous pure lines in a single generation, thus saving many generations of backcrossing to reach homozygosity by traditional means or in crops where self-pollination is not possible. Because doubled haploids are equivalent to inbred lines, their value has been appreciated by plant breeders for decades. The search for natural haploids and methods to induce them has been ongoing since the beginning of the 20th century."

Plants require nutrients in order to grow, develop and complete their life cycle. Mineral fertilizers, and hence the fertilizer industry, constitute one of the most imp- tant keys to the world food supplies. There is growing concern about the safety and quality of food. Carbon, hydrogen and oxygen, which, together with nitrogen, form the structural matter in plants, are freely available from air and water. Nitrogen, phosphorus and potassium, on the other hand, may not be present in quantities or forms sufficient to support plant growth. In this case, the absence of these nut- ents constitutes a limiting factor. The supply of nutrients to the plants should be balanced in order to maximise the efficiency of the individual nutrients so that these meet the needs of the particular crop and soil type. For example, it should be noted that EU-wide regulations are not designed to govern the specific details of mineral fertilizer use. Although plants receive a natural supply of nitrogen, phosphorus and potassium from organic matter and soil minerals, this is not usually sufficient to satisfy the demands of crop plants. The supply of nutrients must therefore be supplemented with fertilizers, both to meet the requirements of crops during periods of plant growth and to replenish soil reserves after the crop has been harvested. Pesticides are important in modern farming and will remain indispensable for the foreseeable future.

This two-volume book is a valuable resource to students, researchers, scientists, commercial producers, consultants and policymakers interested in agriculture or plant sciences particularly in date palm biotechnology. Chapters in Date Palm Biotechnology Protocols: Volume 2: Germplasm Conservation and Molecular Breeding guides readers through methods and protocols on germplasm in vitro conservation, molecular analysis of in vitro cultures, genetic diversity, cultivar identity, gender identification, genomics, and proteomics. Written in the highly successful Methods in Molecular Biology series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Authoritative and practical, Date Palm Biotechnology Protocols: Volume 2: Germplasm Conservation and Molecular Breeding aims to supplement the previous volume and to provide precise stepwise protocols in the field of date palm biotechnology.

Genetic erosion is the loss of genetic diversity within a species. It can happen very quickly, due to catastrophic events, or changes in land use leading to habitat loss. But it can also occur more gradually and remain unnoticed for a long time. One of the main causes of genetic erosion is the replacement of local varieties by modern varieties. Other causes include environmental degradation, urbanization, and land clearing through deforestation and brush fires. In order to conserve biodiversity in plants, it is important to targets three independent levels that include ecosystems, species and genes. Genetic diversity is important to a species' fitness, long-term viability, and ability to adapt to changing environmental conditions. Chapters in this book are written by leading geneticists, molecular biologists and other specialists on relevant topics on genetic erosion and conservation genetic diversity in plants. This divisible set of two volumes deals with a broad spectrum of topics on genetic erosion, and approaches to biodiversity conservation in crop plants and trees. Volume 1 deals with indicators and prevention of genetic erosion, while volume 2 covers genetic diversity and erosion in a number of plants species. These two volumes will also be useful to botanists, biotechnologists, environmentalists, policy makers, conservationists, and NGOs working to manage genetic erosion and biodiversity.

This two-volume book is a valuable resource to students, researchers, scientists, commercial producers, consultants and policymakers interested in agriculture or plant sciences particularly in date palm biotechnology. Chapters in Date Palm Biotechnology Protocols: Volume 2: Germplasm Conservation and Molecular Breeding guides readers through methods and protocols on germplasm in vitro conservation, molecular analysis of in vitro cultures, genetic diversity, cultivar identity, gender identification, genomics, and proteomics. Written in the highly successful Methods in Molecular Biology series format, chapters include introductions to their respective topics, lists of the necessary materials and reagents, step-by-step, readily reproducible laboratory protocols, and tips on troubleshooting and avoiding known pitfalls. Authoritative and practical, Date Palm Biotechnology Protocols: Volume 2: Germplasm Conservation and Molecular Breeding aims to supplement the previous volume and to provide precise stepwise protocols in the field of date palm biotechnology.

Food quality is becoming an ever-increasing important feature for consumers and it is well known that some food crops are perishable and have a very short shelf and storage life. An effective quality assurance system throughout the handling steps between harvest and retail display is essential to provide a consistently good quality supply of fresh food crops to the consumers and to protect the reputation of a given marketing label. Food manufacturing companies all over the world are incre- ingly focussing on quality aspect of food including minimally processed food to meet consumer demands for fresh-like and healthy food products. To investigate and control quality, one must be able to measure quality-related attributes. Quality of produce encompasses sensory attributes, nutritive values, chemical constituents, mechanical properties, functional properties and defects. Successful postharvest handling of crops requires careful coordination and integration of the various steps from harvest operations to consumer level in order to maintain the initial product quality. Maturity at harvest is one feature of quality of perishable products, it has great influence on their postharvest behavior during marketing. Safety assurance can be part of quality assurance and its focus on minimizing chemical and microbial contamination during production, harvesting, and postharvest handling of intact and fresh-cut of commodities. Essentially, electromagnetic (often optical) prop- ties relate to appearance, mechanical properties to texture, and chemical properties to flavor (taste and aroma).

Genetic erosion is the loss of genetic diversity within a species. It can happen very quickly, due to catastrophic events, or changes in land use leading to habitat loss. But it can also occur more gradually and remain unnoticed for a long time. One of the main causes of genetic erosion is the replacement of local varieties by modern varieties. Other causes include environmental degradation, urbanization, and land clearing through deforestation and brush fires. In order to conserve biodiversity in plants, it is important to targets three independent levels that include ecosystems, species and genes. Genetic diversity is important to a species' fitness, long-term viability, and ability to adapt to changing environmental conditions. Chapters in this book are written by leading geneticists, molecular biologists and other specialists on relevant topics on genetic erosion and conservation genetic diversity in plants. This divisible set of two volumes deals with a broad spectrum of topics on genetic erosion, and approaches to biodiversity conservation in crop plants and trees. Volume 1 deals with indicators and prevention of genetic erosion, while volume 2 covers genetic diversity and erosion in a number of plants species. These two volumes will also be useful to botanists, biotechnologists, environmentalists, policy makers, conservationists, and NGOs working to manage genetic erosion and biodiversity.

Food quality is becoming an ever-increasing important feature for consumers and it is well known that some food crops are perishable and have a very short shelf and storage life. An effective quality assurance system throughout the handling steps between harvest and retail display is essential to provide a consistently good quality supply of fresh food crops to the consumers and to protect the reputation of a given marketing label. Food manufacturing companies all over the world are incre- ingly focussing on quality aspect of food including minimally processed food to meet consumer demands for fresh-like and healthy food products. To investigate and control quality, one must be able to measure quality-related attributes. Quality of produce encompasses sensory attributes, nutritive values, chemical constituents, mechanical properties, functional properties and defects. Successful postharvest handling of crops requires careful coordination and integration of the various steps from harvest operations to consumer level in order to maintain the initial product quality. Maturity at harvest is one feature of quality of perishable products, it has great influence on their postharvest behavior during marketing. Safety assurance can be part of quality assurance and its focus on minimizing chemical and microbial contamination during production, harvesting, and postharvest handling of intact and fresh-cut of commodities. Essentially, electromagnetic (often optical) prop- ties relate to appearance, mechanical properties to texture, and chemical properties to flavor (taste and aroma).

The quality of human life has been maintained and enhanced for generations by the use of trees and their products. In recent years, ever rising human population growth has put tremendous pressure on trees and tree products; growing awareness of the potential of previously unexploited tree resources and environmental pollution have both accelerated development of new technologies for tree propagation, breeding and improvement. Biotechnology of trees may be the answer to solve the problems which cannot be solved by conventional breeding methods. The combination of biotechnology and conventional methods such as plant propagation and breeding may be a novel approach to improving and multiplying in large number the trees and woody plants. So far, plant tissue culture technology has largely been exploited in the propagation of ornamental plants, especially foliage house plants, by com mercial companies. Generally, tissue culture of woody plants has been recal citrant. However, limited success has been achieved in tissue culture of angiosperm and gymnosperm woody plants. A number of recent reports on somatic embryogenesis in woody plants such as Norway spruce (Picea abies), Loblolly pine (Pinus taeda), Sandalwood (Santalurn album), Citrus, Mango (Mangifera indica), etc., offer a ray of hope of: a) inexpensive clonal propa gation for large-scale production of plants or "emblings" or "somatic embryo plants," b) protoplast work, c) cryopreservation, d) genetic transformation, and e) artificial or manufactured seed production."

The quality of human life has been maintained and enhanced for generations by the use of trees and their products. In recent years, ever rising human population growth has put tremendous pressure on trees and tree products; growing awareness of the potential of previously un exploited tree resources and environmental pollution have both accelerated development of new technologies for tree propagation, breeding and improvement. Biotechnology of trees may be the answer to solve the problems which cannot be solved by conventional breeding methods. The combination of biotechnology and conventional methods such as plant propagation and breeding may be a novel approach to improving and multiplying in large number the trees and woody plants. So far, plant tissue culture technology has largely been exploited in the propagation of ornamental plants, especially foliage house plants, by com- mercial companies. Generally, tissue culture of woody plants has been recal- citrant. However, limited success has been achieved in tissue culture of angiosperm and gymnosperm woody plants. A number of recent reports on somatic embryogenesis in woody plants such as Norway spruce (Picea abies), Loblolly pine (Pinus taeda), Sandalwood (Santalum album), Citrus, Mango (Mangifera indica), etc. offer a ray of hope of: (a) inexpensive clonal propa- gation for large-scale production of plants or "emblings" or "somatic embryo plants"; (b) protoplast work; (c) cryopreservation; (d) genetic transforma- tion; and (e) artificial or manufactured seed production.

Plants require nutrients in order to grow, develop and complete their life cycle. Mineral fertilizers, and hence the fertilizer industry, constitute one of the most imp- tant keys to the world food supplies. There is growing concern about the safety and quality of food. Carbon, hydrogen and oxygen, which, together with nitrogen, form the structural matter in plants, are freely available from air and water. Nitrogen, phosphorus and potassium, on the other hand, may not be present in quantities or forms sufficient to support plant growth. In this case, the absence of these nut- ents constitutes a limiting factor. The supply of nutrients to the plants should be balanced in order to maximise the efficiency of the individual nutrients so that these meet the needs of the particular crop and soil type. For example, it should be noted that EU-wide regulations are not designed to govern the specific details of mineral fertilizer use. Although plants receive a natural supply of nitrogen, phosphorus and potassium from organic matter and soil minerals, this is not usually sufficient to satisfy the demands of crop plants. The supply of nutrients must therefore be supplemented with fertilizers, both to meet the requirements of crops during periods of plant growth and to replenish soil reserves after the crop has been harvested. Pesticides are important in modern farming and will remain indispensable for the foreseeable future.

Since the beginning of agricultural production, there has been a continuous effort to grow more and better quality food to feed ever increasing popula tions. Both improved cultural practices and improved crop plants have alIowed us to divert more human resources to non-agricultural activities while still increasing agricultural production. Malthusian population predictions continue to alarm agricultural researchers, especially plant breeders, to seek new technologies that will continue to allow us to produce more and better food by fewer people on less land. Both improvement of existing cultivars and development of new high-yielding cultivars are common goals for breeders of alI crops. In vitro haploid production is among the new technologies that show great promise toward the goal of increasing crop yields by making similar germplasm available for many crops that was used to implement one of the greatest plant breeding success stories of this century, i. e., the development of hybrid maize by crosses of inbred lines. One of the main applications of anther culture has been to produce diploid homozygous pure lines in a single generation, thus saving many generations of backcrossing to reach homozygosity by traditional means or in crops where self-pollination is not possible. Because doubled haploids are equivalent to inbred lines, their value has been appreciated by plant breeders for decades. The search for natural haploids and methods to induce them has been ongoing since the beginning of the 20th century."