Preface Excessive use of chemicals and pesticide in agricultural crops is being deplored by the community and scientists. It is because of the fact that, these not only result in environmental and safety hazards but also lead to development of new strains of pests and pathogens. Western countries which at one time advocated the use of these chemicals are now completely against these. They now believe in ‘organic products’ which do not have any utilization of chemical fertilizers and pesticides. As a tool to assist the organic farming, natural fauna and flora has been used for the management of diseases and pests. If we go back to history, our rural used to exchange predatory birds to kill the insects which use to attack their fields. Scientist have come out with many microbes/insects from the native flora/fauna which are a good source of management of diseases. These microbes serves as a “biopesticides’ and are in good demand. Being native in population these are multiplied easily in the host soil and require minimal applications. Furthermore, these have proved very effective against root pathogens. Present book deals with the detailed description about a number of biopesticides which are used for management of fungi, bacteria, virus and nematodes. The traditional aspect of biopesticide management has been described in detail by Prof. P. Narayanswamy, where the editor in his chapter has described the prospects and future of biopesticides. The other chapters provide a detailed insight of various aspects of biopesticides.

Plant diseases caused by variety of pathogens pose a serious challenge and economic threats to various agricultural crops all around the world. It has been evidenced that despite wide use of chemical pesticides in crop production, the losses due to pests and diseases are significant. Phytonematodes are one of the major groups of organisms that live in diverse habitat and continue to challenge variety of agricultural crops all around the world. Since early times the major agricultural crops have been plagued by these noxious nematodes that feed on various plant parts viz. roots, rhizome, sucker, tubers, seedlings, stem, leaves, buds, crowns and cause damage worth more than 100 billion dollars annually. The major crops severely affected by these pests are, vegetables, fruits, sugarcane, sugar beet, cotton, oil seed, pulses, tobacco, tea, coffee, cereals, spices, medicinal and aromatic plants.

Abstract The rhizosphere or the zone of influence around roots harbors a multitude of microorganisms that are affected by both abiotic and biotic stresses. Among these are the dominant rhizobacteria that prefer living in close vicinity to the root or on its surface and play a crucial role in soil health and plant growth. Both free-living and symbiotic bacteria are involved in such specific ecological niches and help in plant matter degradation, nutrient mobilization and biocontrol of plant disease. While the rhizosphere as a domain of fierce microbial activity has been studied for over a century, the availability of modern tools in microbial ecology has now permitted the study of microbial communities associated with plant growth and development, in situ localization of important forms, as well as the monitoring of introduced bacteria as they spread in the soil and root environment. Plant-microbe researchers have studied the diversity of rhizobacteria in a variety of plants, cereals, legumes and others along with assessment of their functionality based on the release of enzymes (soil dehydrogenase, phosphatase, nitrogenase, etc.), metabolites (siderophores, antifungals, HCN, etc.), growth promoters (IAA,

Introduction Soil supports richest number and kinds of microorganisms interacting with each other and thus by modification or alteration in soil conditions greatly influence the microbial community and their activity in soil ecosystem. Soil physico-chemical and the biological factors interact to provide rapidly changing ecological niches and microbial components fluctuate in response to change in soil conditions. There are large evidences that agricultural practices often favour antagonistic microorganisms (Cook and Baker,1983; Yarham,1979) and therefore, biological control of plant pathogens could be possible through manipulation of soil condition. Soil organic matter also has a profound influence on microorganisms in soil, particularly those, including some pathogens, saprophytic and obligate plant parasites. Soil organic matter is distributed at discrete sites within the soil and determines to a great extent which parts of pore space are occupied. 

Introduction Biological-based crop protection against plant viruses aims to develop sustainable, non-chemical, crop management technologies that utilize natural-occurrants and phytotoxins to control economically important diseases. In this area the efforts were made since the realization that viruses can not be controlled directly unlike other pathogen. At present in the absence of any direct control of the viruses, strategies so far have been adopted to control them indirectly; like controlling the vectors of viruses (insects, nematodes, fungi etc.), using barrier crops, and use of resistant cultivars. However, success had been very limited. As the biological sciences advanced, many biological systems were utilized to control the diseases in plants caused by viruses, promising among them is using apical-meristem culture techniques to produce virus free plantlets as starting material.

Agriculture is the main source of income of the rural masses in India and the disease accounts for more than 30% losses every year. According to a WHO estimate of 1990. There were 25 million cases of acute occupational pesticides poisoning in developing countries each year. ILO 1996 estimates suggests that out of 14% of all known occupational injuries 10% of all total injuries are caused by pesticides. Further more developing countries are a dustbin for the developed countries. More than 20, 000 tonnes of obsolete pesticides are dumped in Africa alone. The biopesticides are amenable to small scale and local production. Presently there is an increased awareness regarding environmental and food safety. The biopesticides as such can be used as an essential and fundamental component of integrated pest management. It helps to manage the disease which are difficult, otherwise to be managed and so also these control the pests resistant to conventional pesticides. Paulitz and Belanger (2001) has reviewed the potential of biological control in green house systems.

Systematic management of plant diseases dates back to 1885 with the invent of Bordeaux mixture by Milardet. Thereafter, a number of contact and systemic fungicides have been reported over the years for the management of various plant pathogens, of which many have become obsolete and many are still being used with excellence. However, the ecological hazards caused by the chemical fungicides have prompted scientists to search for other avenues of crop protection. Most of the conventional chemical and biological plant protection procedures, as well as the use of disease-resistant cultivars, tend towards the direct control of pests and diseases by their elimination. But these practices generally and particularly in case of monoculture crops like rice, raise problems. The risk of developing pesticide resistance in plant pathogens is enhanced by the long term use of the same chemical. The resistance genes of the plants can also be overcome by changes in the pathogens. Therefore the situation demands development of new strategies for plant protection which can supplement the use of resistance breeding and chemical control.

Abstract Plant roots influence the biological, chemical and physical properties of rhizosphere soil. These effects are a consequence of their growth, their activity and the exudation of organic compounds from them. There is now considerable scope for the new ideas to be extended to the rhizosphere. The role of soil microorganisms in sustainable productivity has been well construed. In recent years, root inhabiting (rhizozosphere) bacteria (rhizobacteria) is gaining importance. The beneficial effects of plant growth promoting rhizobacteria (PGPR) has been variously attributed to their ability in improving the crop production, protection against phytopathogens, soil health and environmental quality. However, there is a need for isolation, identification and improvement of potent PGPR’s to utilize them ultimately as promising bio-inoculants. This review embodies some recent developments to evolve strategies for the better biotechnological exploitation of PGPR’s.

Abstract Surveys made systematically in different remote places of Tamil Nadu brought to light more than 1000 indigenous techniques adopted for pest control in various crops of agriculture, horticulture and store grains. Target animals included array of insect species and animal pests namely rodents, mites, molluscs and microbes like nematodes and viruses. Various kinds of plant species reveal their modes of action distinctly.

INTRODUCTION Plant diseases need to be managed for maintaining the quality and abundance of food, feed, and fiber produced by growers around the world. Different approaches may be used to prevent, mitigate or control plant diseases. Beyond good agronomic and horticultural practices, growers often rely heavily on chemical fertilizers and pesticides. Such inputs to agriculture have contributed significantly to the spectacular improvements in crop productivity and quality over the past 100 years. However, the environmental pollution caused by excessive use and misuse of agrochemicals, as well as fear-mongering by some opponents of pesticides, has led to considerable changes in people’s attitudes towards the use of pesticides in agriculture. Today, there are strict regulations on chemical pesticidal use, and there is political pressure to remove the most hazardous chemicals from the market.

Vegetables have got an important place in agriculture development, human diet and economy of the country. All the developed and developing countries realized the importance of vegetables an essential diet due to medicinal and nutritional value for human health. There is a steady upward trend in vegetable production. China is ranking first in the world and currently produces 237 million tonne of vegetables. India has made a quantum jump in vegetable production securing the second position in the world. The total production of vegetable is more than 91 million tonne in the country. Diseases and pests are the most important factors for low vegetable production. Various fungi, bacteria, viruses, phytoplasmas, nematodes and weeds are responsible for causing diseases in vegetables resulting heavy reduction in yield and quality.