eChapters

Norman Borlaug’s early upbringing in an Iowa farm and his experience of hardship during the US Depression of the early 1930s instilled in him the desire to bring science to address the problems of low farm productivity, poverty and hunger. After completing his Ph.D degree in Plant Pathology at the University of Minnesota in 1942, he joined the Rockefeller Foundation’s agricultural programme in Mexico, leading to the birth of the International Maize and Wheat Improvement Center (CIMMYT). There he began his work on wheat, concentrating on the control of stem, stripe and leaf rusts, the important diseases of the crop. He introduced a multi-pronged approach to manage the rust fungus, including the development of composite varieties characterised by phonotypic identity but genotypic diversity with reference to resistance to different races of the pathogen, an approach conferring enduring resistance as a result of reduced pressure on the fungus to mutate and create more virulent strains.

Bhutan has developed the concept of Gross National Happiness (GNH) as a substitute for Gross Domestic Product (GDP). In this theory, GNH comprises spiritual and cultural values, including love of sport, music, dance and spiritual activities. This is a good departure from measuring happiness purely from the view point of money. I would like to elaborate on four pillars that are necessary to uphold sustainable human happiness.

Ecology

There is an increasing awareness of the need for adopting sustainable lifestyles which will not make a heavy demand on our life-support systems of land, water, biodiversity, forests, oceans and climate. In his book titled World on the Edge.1 Lester Brown has described how we still have time to prevent environmental and economic collapse. Recent calculations on the ecological footprint each one of us is leaving behind shows that our per capita consumption of natural resources is exceeding the biocapacity of our earth. Soon we will need two planets to meet the growing demand for land, water, forests and biodiversity. In this context, we should keep in view what Mahatma Gandhi said long ago: 

An ancient Chinese proverb says

If you are thinking one year ahead, plant rice
If you are thinking ten years ahead, plant trees
If you are thinking hundred years ahead, educate the people

Subramanya Bharati, a great Tamil poet, wrote decades ago that nutrition and education were the two legs of a human being — nutrition for the body and education for the mind. We must, therefore, foster a movement for integrating academic excellence and social relevance in the curricula of our educational institutions. Our universities should promote the growth of the science of ecotechnology, which is the product of the integration of traditional knowledge with frontier science. This will need a mind-set change in relation to the knowledge and wisdom of our tribal and rural families.

In the 1990s, I developed the Iwokrama Rain Forest Programme, which represents the world’s largest adventure in the sustainable management of rainforests. The local Amerindian population welcomed me to Iwokrama with a song, which translates thus:

On August 6, 1945, the most dreadful among the weapons of mass destruction – the atom bomb – was dropped in the civilian area of Hiroshima. Three days later, another atom bomb was dropped in Nagasaki. In July 1955, Bertrand Russell and Albert Einstein issued their famous manifesto seeking the abolition of nuclear weapons and appealing to all inhabitants of Planet Earth:
 
Remember your humanity, and forget the rest. If you can do so, the way is open to a new Paradise; if you cannot, there lies before you the risk of universal death.

In 1957, the Russell-Einstein Manifesto led to the birth of the Pugwash Conferences on Science and World Affairs, an organisation devoted to the causes of ending the nuclear peril and reminding scientists of their ethical responsibility for the consequences of their discoveries, particularly in the area of nuclear threat to human survival.

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.

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.

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.

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.

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.

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.

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.

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. 

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,

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

Nitrogen is an important nutrient for growth and development of plants. Presence or absence of nitrogen often affects the amino acid composition of proteins, which may in turn change its nutritional quality. Increase in the elevated CO₂ concentration and temperature associated with future climates are expected to affect the nitrogen use efficiency (NUE), growth and grain yield of wheat (Triticum aestivum L.). Atmospheric CO₂ is steadily rising from the current level of approx 384 µLL^-1 and is expected to rises upto 550 µLL^-1 by 2050. It is predicted that the global temperature would increase by 1.5- 4.5^oC. The main future challenge is to feed nine billion people under an altered climate, as this increase in global temperature would affect, negatively or positively the future crop productivity including wheat depending upon the geographical location. The present book chapter summarizes the potential impact of elevated CO₂ and temperature on NUE of Triticum aestivum L.

Introduction

Plantation crops are high value commercial crops which are broadly classified as estate crops consisting of crops like tea, coffee and rubber and small holders plantation crops like coconut, cashew, arecanut, cocoa etc. Spices especially black pepper, cardamom, vanilla, tree spices like clove, nutmeg, cinnamon and allspice are generally grown as mixed crops in perennial cropping systems. In India, plantation crops including spices are grown in an area of three million hectares and generate an annual income of more than Rs, 5,53,630 million. They are valued for multifarious uses to meet the human needs such as food, oil, industrial raw materials, beverages and confectionary items. Pests and diseases are the major limiting factors in increasing the productivity of these crops. Among the pests, nematodes have got a major role in devastating the pepper plantations by the involvement in slow wilt disease, nematode diseases of cardamom nurseries, root-knot nematode infestation in ginger, turmeric, clove, nutmeg, allspice, lesion nematode infestation in tea, coffee, etc.

Introduction

Biological control of plant pathogens is currently accepted as a key practice in sustainable agriculture. Plant parasitic nematodes and mycorrhizal fungi are commonly found inhabiting the same soil and colonizing roots of their host plants. These two groups of microorganisms exert a characteristics, but opposite effect on plant health. The potential role of mycorrhizal fungi as biocontrol agent for the control of nematode plant diseases has recently received considerable attention. The literature on the various aspects of VAM research such as interaction of VAM- mycorrhizal fungi with nematode pathogens (Sikora, 1995, Pinochet et al. 1996), biotechnology and future of VAM commercialization (Wood and Cumming, 1992) and trends in mycorrhizal research (Sahay et al. 1998) has been reviewed. The damage due to nematodes diseases is generally decreased in mycorrhizal fungi has shown an antagonistic influence on the population of plant parasitic nematodes (Nagesh et al. 1999, Kantharaju et al.

Protected Cultivation

Protected cultivation (PC) may be defined as the “modification of the natural environment to achieve optimum plant growth” (Singh, 2005). Modifications can be made to both the aerial and root environments to increase crop yields, extend the growing season and permit plant growth during periods of the year not commonly used to grow open field crops. PC may also indicate comprehensive systems of ‘Controlled Environmental Agriculture’ in which all the aspects of natural environment are modified for maximum plant growth and economic return.

Introduction

Nematodes are cosmopolitan and ubiquitous in occurrence. These have been reported in all kinds of ecological niche. Accordingly, different kinds of nematode fauna had evolved with distinct morphological features and physiological variability. However, development and perception keep changing with the ambient environment. Agriculture has progressed with leap and bounce as human being has managed this to its maximum utility. The fast changes in agriculture definitely influenced the ecological niche and affected the flora and fauna. Consequently, specific and unspecific kind of relation evolved between host and parasite. With the thumb rule of ecological balance or homeostasis. In the dynamic Mother Nature, multispecies heterogeneous complex is sustained and nature do not perpetuate homogeneity.

Introduction

Banana is the forth ranked agricultural crop in the world and first among fruits. A large number of pests and diseases threaten banana production. The major constraints in production are diseases and pests transmitted through the conventional planting materials. Although the average yield for bananas worldwide is over 40 t per hectare, production in India averages only 20 t per hectare. The nematode parasites are among the most important pests on commercial and subsistence banana production and their control remains difficult, as the nematodes are involved in the destruction of primary roots that disrupt the anchorage system resulting in toppling or uprooting of plants. The most widespread and important are burrowing nematode, Radopholus similes, some species of root lesion nematode, Pratylenchus coffeae and P. goodeyi, species of root knot nematode, Meloidogyne incognita and M. javanica; the spiral nematode, Helicotylenchus multicinctus, H. mucronatus and semi endo-parasitic nematode Rotytlenchus reniformis.