eChapters

Microorganisms live as single cells in nature in association with other cells in assemblage that we call “Population”. Such populations are composed of group of related cells generally derived by successive cell divisions from a single parent cell. The location in an environment where a population generally lives in association with other populations of cells called “Microbial communities”. Environmental microbiology deals with the study of these microbial communities in different habitats, naturally occurring on earth.

Natural habitats of microorganisms are exceedingly diverse. Any habitat that is suitable for the growth of microorganisms can also support the growth of other microorganisms. But in addition, there are many habitats where, extreme environment, due to chemical and physical factors, higher organisms cannot grow but microorganisms can grow and flourish. In this chapter, different habitats of microorganisms are discussed briefly.

Because microorganisms are so small, their habitats are also small. The term microenvironment is often used in ecology to describe where a microorganism actually lives and metabolites within its habitat.

Introduction

Agriculture occupies a prominent place in Indian economy and rural livelihoods. But, it is faced with the challenge of producing food for a rapidly growing population whilst maintaining the nation’s fragile resources.Efforts through green revolution brought out significant increase in food grain production by concentrating on the potential farms in terms of irrigation and other basic resources.Nationally and globally, it is necessary that the growth rate of food production must remain higher than the population growth rate to avoid hunger and overcome famines. But, food security one of the basic human rights is in jeopardy, today. Agriculture is crucial for ensuring the food and livelihood security of the country and hence it is important that this sector with diversified farming systems becomes resilient to increasing climatic variabilities and global economic changes. This concept encourages the farmers towards efficient utilization of natural resources and also proper channelization of by-products of one enterprise to the other enterprise in farming. The integrated farming systems, therefore, assume prime place for sound management of farm resources to enhance the farm productivity, reduce the environmental degradation, and improve the quality of life of resource poor farmers and to maintain the sustainability to meet the challenges of food security. In order to meet the soaring demand for food there is a need to go for integrated faming system.This approach facilitates in strengthening the socio-economic status of Indian farmers besides strengthening ecological balance. Integrated farming system is common to Indian farmers simply because of the preponderance of small farm systems which form the backbone of traditional agriculture. For small farmers, these systems enable a means of diversifying the use of meagre resources in the context of a rational means of reducing risk. Additionally, it also enables increased efficiency in the use of these same resources in a manner that there will be livelihood security and stability to farming systems. There is no scope for increasing the farm size. Yet steady increase in population with shrinkage of cultivated land as a result of industrialization and urbanization would pose serious hurdle for agricultural development. Only vertical expansion is possible by integrating appropriate farming components requiring lesser space and time ensuring continuous income to the farmers.

Rice is the most important cereal crop of India occupying about 44.0 million hectares land. It provides food and employment to millions of people in the country. Despite development of high yielding varieties and technological interventions the yield of rice is still low (3.20 tonnes/ha) in India. The reasons for low yield of rice are:

Lesser area under high yielding varieties

Limited availability of quality seed

Increased acidity/ sodicity in some parts of the country

Declined soil fertility

Unavailability of inputs, like fertilizers and seed, in time

Inefficient nutrient management including imbalanced use of nutrients

Improper crop rotations

Reduced availability of irrigation water

Inefficient management of weeds, diseases and insect-pests

India ranks third after China and Canada in the world in production of edible oilseed crops. Average yield of rapeseed-mustard in the world is 2043 kg/ha. Average yield of European Union, Canada and China is higher than India. Higher yield in these countries is due to cultivation of long duration varieties suitable for their local climatic conditions. Duration of favorable climatic condition to grow rapeseed-mustard is shorter in India as compared to EU, Canada and China, which enforces cultivation of short duration varieties (130-145days). Rapeseed-mustard contribute one third in the production of edible oils in India. These crops ranks second in area and production after soybean. Total area and production under these crops is 5.80mh and 6.28mt respectively. It is necessary to mention that total water requirement of these crop is 80-240mm, which is very low as compared to other crops. These crops pay higher return by utilizing low inputs, thus, are highly remunerative for the farmers.

Rapeseed-mustard group of crops are mainly cultivated in irrigated areas where at least one irrigation facility is available and only 24.0% of area is under rain-fed situation. Five states of India namely, Rajasthan, Uttar Pradesh, Haryana, Madhya Pradesh and West Bengal contribute 82.00% and 85.67% in total area and production, respectively, under these crops. In Madhya Pradesh 53.2% of total area is irrigated with average yield of 1006 kg/ha, however, 76.6% of total area of country is irrigated even then average yield is only 1083 kg/ha. The lower average seed yield can be attributed to (i) cultivation of very short duration and low yielding B. rapa genotypes in Eastern and North-Eastern states; (ii) susceptibility of varieties to different pests; and (iii) high temperature stress at seedling and reproductive stage. Out of total area under these crops, Indian mustard (Brassica juncea) is grown over more than 80% area. Cultivation of Indian mustard has also been taken up in non-traditional areas of southern states of India viz., Karnataka, Tamilnadu and Andhra Pradesh, recently. This has become possible due to its higher average yield, tolerance against different biotic and abiotic stresses, availability of varieties with 100-152 days maturity, and non-shattering behaviour.

Introduction

Lentil is one of the important Rabi pulses. It is one of the oldest pulses crops and the most nutritious of the pulses. It has the potential to cover the risk of dryland agriculture. It is also used as a cover crop to check the soil erosion in problem areas. It is mostly eaten as ‘dal’. Lentil can also be used as green fodder. Its straw is also used as cattle. Being a leguminous crop, it restores the soil fertility.

Area of cultivation

Lentil is mostly cultivated in the northern and central parts of India. The important lentil growing states are Madhya Pradesh, Uttar Pradesh, Bihar, West Bengal, Orissa, Haryana, Rajasthan, Punjab and Assam. Uttar Pradesh and Madhya Pradesh together contribute 78% towards total national area as well as production.

Climatic requirements: Lentil requires cold climate during growth and warm temperature at the time of maturity. It can tolerate cold and frost winter up to great extent. The optimum temperature for growth is 18-30 degree centigrade. Excessive drought and/or high temperatures during the flowering and pod-fill period also reduce yields.

Soil: Lentil can be grown on a variety of soils such as light loams; alluvial soils and black cotton soils. This crop is also suited to the poorer types of soils, low lying areas such as paddy fields. Lentil does not tolerate flooded or waterlogged soils. Good drainage is required, because even short periods of exposure to waterlogged or flooded field conditions kill plants. A soil pH near 7.0 is best for lentil production. Acidic soils are not fit for growing lentil.

Rice is the most important crop in India occupying about 43.7 million hectares area with a production of 136.5 million tonnes (rough rice/ paddy). As the human population is increasing, so is the demand for rice, yet yields of the crop are leveling out. At present, the rice yield in India is 3.12 t/ha as against the world average of 4.11 t/ha. Not only this, the rice yield in India is exactly half than that of China (6.26 t/ha). The World Development Report 2008 predicts that cereal production would have to increase by 50% by 2030 to meet the escalating worldwide demand. The additional rice for increasing population will have to be produced on less land with less water, less labour, and reduced inputs.The major constraint in rice production in India is the lack of suitable crop management practices and sufficient irrigation facilities. The water crisis is threatening the sustainability of the irrigated rice system and food security in many parts of the world. Despite efforts on a variety of fronts, including genetic engineering of rice strains for improved yield and nutrition, no concrete solution has been found yet. There is a challenge to develop novel technologies and production systems that allow rice production to be maintained or increased in the face of declining water availability. To produce 1 kg of grain, farmers have to put 2 to 3 times more water in rice fields than in those growing other cereals.

The increasing water need for agriculture poses a potential threat to natural water resources and climatic change scenarios in the near future. The great challenge will be to increase food production with less water, particularly in countries with limited water and land resources, by promoting techniques and cropping systems of higher water-use efficiency (WUE).There is also much evidence that water scarcity already prevails in rice-growing areas in India, where rice farmers need technologies to cope with water shortage and ways must be sought to grow rice with less water.The farmers, especially those, who are resource-poor, are losing interest in rice cultivation as its profitability is declining with the rise in input costs. But, system of rice intensification (SRI) and aerobic rice culture appear to be a viable alternative of rice cultivation that may save the expensive inputs, improve soil health/ quality and protect the environment substantially.

Sugarcane is the most important sugar crop contributing more than 62% of the world's sugar production. With increasing human population in the world, sugar requirement has also gone up. Molasses is an important by-product of sugar industry. It is used for the production of alcohol by the distillaries. Alcohol serves as a base material in pharmaceuticals and several other industries. The manufacture of gur (jaggery) and khandsari as alternative sweetening agents in India from sugarcane also plays considerable role in the Indian economy, particularly in rural area. Nearly 40 % of the sugarcane produced is utilised for manufacture of gur and khandsari. Sugarcane is bound to play a greater role in the Indian economy in the years to come by offering a stable income to the farmers by way of cane price, by providing employment to rural masses, by realising excise duty, Cane Cess/ purchase tax and foreign exchange earning.

Acreage and production

Sugarcane is grown in tropical and sub tropical regions. Brazil has largest area and production of sugarcane.India is second to Brazil in sugarcane production. It is followed by Cuba and China. Other important cane growing countries are Pakistan, Mexico, South Africa, Australia, Indonesia etc. So far, as average sugarcane productivity is concerned Peru ranks first in average sugarcane yield. To meet the sugar requirement of increasing population in future, it is essential that sugarcane production is stepped up. Since there is no scope at present to bring additional land under sugarcane, productivity of sugarcane, the targets have to be achieved only through increased productivity.

India has made a considerable progress during the last three decades in horticulture production in India producing 300.6 million tonnes of horticultural produce from 24.85 million hectares in 2016-17. The average productivity of different horticultural crops is quite low as compared to the best yields at national and world level, indicating the scope to enhance the yield in different horticultural crops by many fold along with its quality specially in vegetables. Unlike vegetables, flower cultivation is growing at a very fast speed and registered a marked growth along with employment generation through protected cultivation. According to NHB (National Horticulture Board), during the year 2014-15 the area under floriculture production in India was 248.51 thousand hectares with a production of 1,658 thousand tonnes loose flowers and 484 thousand tonnes cut flowers. However, India’s total export of floriculture was Rs. 548.74 crores/ 82.05 USD Millions in 2016-17. This is because of an appealing gap between potential yield and the actual yield of various vegetable crops. In many vegetable crops, the yields realized are even less than 50 % of their potential yield. Due to fluctuating market prices and poor storage infrastructure available for horticultural crops, farmers are not able to get their production cost. Though, there are some crops, fetches high prices during off-season. Several biotic and abiotic stresses are major factors, responsible for low productivity and poor quality in several horticultural crops under their open field cultivation during rainy and post rainy season more specifically, in vegetables. The increasing demand of off-season and high quality vegetables in various markets of the big cities has drawn the attention of the vegetable growers for diversification from traditional system.

India has emerged as the second largest producer of vegetables 176.17 mt after China 573.93 mt in the world and is gradually striding towards achieving food and nutritional security at national level. The average productivity of vegetable crops is 17.6 t/ha (NHB, 2015) which is comparatively lower than the productivity of China (23.4t/ha), Spain (39.3t/ha) and USA (32.5t/ha). The lower productivity could be attributed to limited use of quality seeds, inefficient production management, impact of biotic stress and climatic factors during crop production. Among the limiting factors limited availability of quality seed is one of the important factors. Since, the performance of other inputs is also depend on the quality of seed. At present the seed replacement rate among vegetable crops is around 25%, whereas highest in cabbage (>90%) followed by tomato, capsicum, bitter gourd, muskmelon, bottle gourd etc.The use of hybrid seed is in increasing due to higher productivity, tolerance to biotic and a biotic stresses and better market value than the open pollinated varieties but the higher price of the hybrid and their availability is still a constraint in adopting the use of hybrid seeds among small and marginal farmers.

The floriculture has become an important sector all over world. In India, floriculture has been associated with culture and heritage since very ancient time. In recent decades there has been increasing in demand of floriculture products with increasing income. It is souring industry in Asian countries including India. Floriculture is an emerging area with great potential both in the domestic as well as export market.In India, commercial floriculture is ongoing development but have a long tradition of various types of flowers.Floriculture was being cultivated in 3.5 lakh hectares in the country and 250 varieties of flowers exist in the country.Besides potted plants, roses, carnation, orchids and chrysanthemum are important cut flowers, which are popular in our country. In the increasingly competitive international cut flower and pot plant market, new and novelty ornamental plants plays an important role in stabilization and expanding market share. Always novelty has been considered as an important attribute in ornamental industry. The consumer choice is also changing for product quality level depending upon purpose of purchase, as well as for higher levels of services and a wider and deeper assessment suggesting product diversification. The increasing pace of agricultural transformation in India has been characterized by widening share of commercial crops in the overall basket. Among others, horticulture has shown great promise because of the availability of high-value domestic and international market against the low production base so far. Understandably, it has received special attention of policy-makers and being termed as the sunrise industry within agriculture. India, with its varied agro-climate is ideally suited for growing several types of flowers in different seasons. Although traditional ornamental crops will continue to play key role in the floriculture trade, a distinct trend towards increasing the share of new crops is clearly evident in recent years often referred to as ‘specialty flowers’, these are cut flowers, which are not widely known and also grown in small pockets but have high prospects in the international market. There are over 60 types of new ornamentals, which have been reported to hold potential for commercial utility. Some progressive growers in India have already initiated the process of introducing new ornamental crops in their fields.These new products normally fetch high prices than the traditional crops for a certain period, but quite often the prices drop when market is saturated. By that time new products should be ready to enter the market. In this context introduction of new ornamental crops is therefore continuous effort.

Fruit production is gaining momentum in the country. With the production about 90.18 million tonnes of fruits from 6.30 million ha in 2015-16, India is the second largest producer of the fruits in the world after China. During the past three decades, international trade in fruits has seen a rapid expansion.The newer markets are now opening for Indian produce e.g. Japan and USA have opened the route for Indian mangoes. At domestic level, the increase in demand of fruits for consumption both in fresh and the processed form has been evident. The income and livelihood security from this sector are increasing. The government has also supported the horticulture sector particularly area expansion and productivity enhancement of fruits through technological interventions like drip irrigation, fertigation, emphasis on integrated nutrient management, production of high quality planting material etc. Selection of an ideal variety and availability of plant material from a reliable source is the basis for achieving high yield and quality uniform produce. Lack of clonal uniformity not only leads to the problems in crop management but also the differences in maturity may cause delay in commercial picking. A number of improved fruit crops’ varieties have been developed during past few years, which ranged from the high yielding to stress resistant to high quality produce. In fruits and plantation crops more than 150 high yielding varieties suitable for various purposes have been developed. A list of some popular cultivars and new cultivars in major fruit crops has been given here (Table 1).

Indian horticulture has made a rapid stride, converting the country from food scarce to self sufficiency. The horticulture, which includes fruits, vegetables, spices, flowers and medicinal and aromatic plants, has proved beyond doubt its potentiality for gainful diversification. One of the significant developments is that horticulture has moved from rural confine to commercial production, and this changing scenario has encouraged private sector investment in production system management. Since the growing of fruit crops is highly rewarding to the farmers in terms of returns per unit area, the horticulture sector is expected to contribute significantly for the food and nutritional security, employment opportunity and poverty alleviation.

In recent past, several innovations and new initiatives have been made both in research and development for improving production, productivity, quality and marketing and to identify critical gaps in various emerging areas in fruits & horticulture technology. Some of the brief details are discussed on under:

High yielding superior fruit varieties for commercial cultivation

Mango: The mango varieties have been developed as a national priority at IARI, which are highly popular amongst the fruit growers of India. The important features of these hybrids are summarized below:

Crop diversification has been well recognized as an effective strategy for achieving the objectives of food and nutritional security, income growth, poverty alleviation, employment generation, judicious use of land, water and other natural resources, sustaining agricultural development and environmental improvement. Vegetable crops being rich sources of various health building substances, especially vitamins and minerals, offer unique advantage for food and nutritional security, tackle malnutrition and dietary deficiency diseases. Besides, their high yield potential per unit area and time, diverse varietal wealth, labour intensiveness, high market price and prospects of processing, value addition and export, they play an important role in employment generation, and livelihood improvement. Since India is endowed with diverse agro-climatic conditions, almost all kinds of vegetable crops are grown in one or other corner of our country. More than 200 different vegetables are grown in India, of which, about 70 types are cultivated commercially. Vegetable production scenario in India has made a remarkable progress since independence from a meagre production of 17.5 million tonnes to 146 million tones, with a productivity of 17.3 t/ha. India is the second largest vegetable producer in the world after China. However, it needs to be doubled by 2020 in order to meet the nutritional requirement of burgeoning population in the country. With increasing purchasing power of people, the demand for vegetables has increased enormously, as a result the prices of vegetables have increased and it has been the dominant factor for high inflationary pressure in Indian economy during recent years. Inclusion of different vegetable crops with shorter maturity period in the prevailing cropping system will enhance the total system productivity, which may go a long way in improving the economic as well as physical health of small and marginal farmers.

The solanaceous group of vegetables (tomato, eggplant, chili and bell peppers) generally take up large amounts of nutrients. The amount of nutrients they take up depends on the quantity of fruit and dry matter they produce, which in turn is influenced by a number of genetic and environmental variables. Tomato (Solanum lycopersicum L.) known as Tamatar in Hindi is one of the most popular and widely grown vegetables in the world ranking second in importance to potato in many countries. Tomato is widely grown in almost all parts of India and is adapted to wide range of soil and climate conditions. Tomato is consumed either as raw or cooked and is also very important crop for processing in the form of soups, juice, ketchup, puree, paste and powder. Tomato adds variety of colours and flavour to food.

Tomato is very well known for its nutritive value. Attractive red colour is due to lycopene pigment, pink and yellow colours are due to presence of anthocyanin and carotene pigments. Tomato is rich source of ascorbic acid, which varies from 15-31 mg per 100 g of fresh weight. Tomato also provides minerals like calcium, iron, magnesium, phosphorus and sodium. Tomato is also rich in medicinal value. The pulp and juice is digestible, promoter of gastric secretion and blood purifier. It is also considered to be intestinal antiseptic. It is one of the richest vegetables, which keeps our stomach and intestine in good condition.

Weeds have been existing on the earth ever since the man started domesticating /cultivating plants and animals around 10,000 B.C. and recognized as a problem since then. The battle against weeds is a never ending one and often the costliest agronomic input for successful crop production. Weeds are most under estimated crop pests in tropical agriculture although they cause higher reductions in crop yields than other pests and diseases. Of the total annual loss of agricultural produce from various pests in India, weeds roughly account for 37%, insects for 29%, diseases for 22% and other pests for 12%. Weeds decrease quantity and quality of the produces [food, fibre, oil, forage/ fodder, animal products (meat and milk)] and cause health hazards for humans and animals. Therefore, weed control is very important for a successful crop production.

Plant parasitic nematodes are microscopic, thread like, soil-born organism, found in every conceivable environment. Severity of nematodes as plant pathogen is more a problem in tropical than temperate climate. These organisms are basically root feeders causing injury to the plants, which adversely affect the function of the root to absorb and translocate nutrients and water efficiently. This result into nutrient deficiency like symptoms, and as such nematode problems go unnoticed. Such symptoms are not corrected even after a dose of fertilizers.

Based on feeding habits, they are classified as migratory ectoparasitic, sedentary semi-endoparasitic or endoparasitic nematodes. They feed silently but constantly without killing the host producing debilitating symptoms and in the process reproducing to great numbers at the end of the crop season. Normally, nematodes complete their life cycles in a span of 20-25 days at temperature of 25-30 °C. They have a great egg laying capacity, which varies from 40-1000 eggs.

The most important nematode is root-knot nematode, Meloidogyne sp. distributed worldwide and can infest more than 2000 species of plants. Cereal cyst nematode, Heterodera avenae - an important nematode pest of wheat, barley and oat, citrus nematode, Tylenchulus semipenetrans associated with citrus dieback and slow decline, burrowing nematode, Radopholus similis causing spreading decline in plantation crops, the reniform nematode, Rotylenchulus reniformis in vegetables and cotton and the rice root nematode, Hirschmanniella spp in lowland rice are few other damaging nematodes.

Insect pests, diseases and weeds are major biotic bottlenecks in the production of crops, inflicting on an average about 30% yield loss. Monetary value of these losses has been estimated to be exceeding Rs 1,00, 000 crores. There is thus ample scope to enhance our food production by curtailing losses due to pests to certain extent. Only option to boost our production remains in growing improved crop cultivars with better pest management options. Mainly synthetic pesticides have been used to combat pest menace in agriculture and public health. Pesticides have, of course, played a commendable role in increasing our food production and protecting us against disease vectors. However sole reliance on pesticides has created several problems such as development of resistant pests, pest outbreaks, mortality of useful organisms, adverse effect on human health and environmental degradation. Adverse effects of pesticides prompted scientists to look for safer and environment friendly methods of pest control and consequently concept of pest management came in to being.

Pest management is known as an ecological approach to tackle pest problems, because here emphasis is on containing pests in such a way that other biotic components of the system such as natural enemies, human beings and wildlife etc are not harmed and environment is preserved in general. Pest management works on the premise that all pest population levels are not injurious to crops and crops can always compensate for certain injury due to pests. Moreover, some pest population is always required for the survival of natural enemies of the pests. This has given rise to the concept of economic injury level (EIL), which helps to avoid unwarranted application of pesticides. The EIL based pesticide application ensures favourable cost-benefit ratio to farmers. Pest management also underlines that pest control tactics should be socially acceptable and within the reach of farmers. It is a holistic approach to pest problems in which we aim to protect our commodities against all the pests and ensure production of healthy crops.

Scientific agriculture is the only solution for increasing productivity of various crops and the input resources most effectively. Fertilizer, the most efficient and often the most expensive input can be applied to crops on the basis of generalized state level fertilizer recommendations. However, state level fertilizer recommendations do not take into consideration fertility status of the field which is neither uniform nor constant and which varies from field to field. Sometimes more fertilizers are added leading to unnecessarily higher investment, while under another situation, inadequate quantities of fertilizers may be added, resulting in lower returns. Inefficient and imbalanced uses of fertilizers affect both soil health and agricultural productivity.

Therefore, the best and most effective method for fertilizer recommendation is soil testing. It is a mode of assessing the nutrient supplying capacity of a soil.

What is biofertilizer?

Biofertilizers are ready to use live formulates of such beneficial microorganisms which on application to seed, root or soil mobilize the availability of nutrients by their biological activity in particular, and help build up the microflora and in turn the soil health in general.

Why should we use biofertilizers?

With the introduction of green revolution technologies the modern agriculture is getting more and more dependent upon the steady supply of synthetic inputs (mainly fertilizers), which are products of fossil fuel (coal+ petroleum). Adverse effects are being noticed due to the excessive and imbalanced use of these synthetic inputs. This situation has lead to identifying harmless inputs like biofertilizers. Use of such natural products like biofertilizers in crop cultivation will help in safeguarding the soil health and also the quality of crop products.

Indian agriculture, accounting for 25% of the nation’s Gross Domestic Product (GDP), 15% of exports and 60% of the employment continues to be the mainstay of economy. Having achieved laudable success in agricultural production in the last 50 years (50 Million ton to 210 Million ton) India has transformed herself from a food deficit country to a food surplus country. Still there are many challenges, which Indian agriculture is facing, in a fast changing technical and socio-economic scenario. Relating to the natural resources and production base, water has emerged as the most crucial factor for sustaining the agricultural sector. India accounts for 16 percent of the world’s human population and nearly 30% of the cattle with only 2.4% of the land and 4% of the water resources.Even if the full irrigation potential is exploited, about 50% of the country’s cultivated area will still remain unirrigated, particularly with the current level of irrigation efficiency. The share of water for agriculture would reduce further with increasing demand from other sectors. But the water demand for agricultural purposes is estimated to increase in order to produce more cereals, horticultural produce and raw material for a fast expanding food industry. Efficient management of water is, therefore, key to future growth of Indian agriculture. The requirement of water by all sectors in 2025 is estimated to be 105 M ha m (Water Resources Development in India, 2010). Share of water for agriculture is expected to get reduced from the present level of 85 % to 69 % by 2025. On the other hand, the actual agricultural water demand is estimated to increase from 470 Billion Cubic Meters (BCM) in 1985 to 740 BCM in 2025. During the same period, the demand for non-agricultural use of water will multiply fourfold from 70 BCM to 280 BCM. The water use efficiency (WUE) in Indian agriculture, at about 30-40%, is one of the lowest in the world, against 55% in China.

As early as in the 18^th century, the anaerobic process of decomposing organic waste was known. During 19^th century, it became clear that anaerobic bacteria are involved in the decomposition process (DST, 1981). Since that time, the applications of anaerobic digestion have grown steadily, in both its microbiological and chemical aspects. The process of anaerobic digestion possesses a double advantage i.e. the process in addition to providing good quality manure also supplies a large volume of combustible gas. Anaerobic digestion provides some exciting possibilities and solutions to such concerns as alternative energy production, handling of human, animal, municipal and Agro-industrial wastes safely, controlling environmental pollution and expanding food supplies. The technology of anaerobic digestion (Kumar et al., 2015) has not yet realized its full potential for manure and energy production even in developed and industrialized countries. In developing countries expansion of this technology has been hindered because of the need for better economic initiatives, organized supervision, proper training and education.

During twentieth century, the method of anaerobic fermentation or digestion was successfully applied by sewage chemists. A considerable amount of research work was carried out by sewage chemists on different aspects of the digestion process and sludge digestion plant, were installed. The gas produced was used for burning as domestic fuel, operating machinery and for tractors. In this context, the studies on anaerobic digestion of cattle dung and vegetable waste has been important. The work is particularly important ones in the Indian context as long as gas production and plant design efforts are concerned. For research on anaerobic digestion energy part (methane generation) received more attention since the early decades of this century when research into bio digestion had gradually begun to take shape. Fertilizer aspect received occasional attention a couple of decades later. The engineering and micro biological aspects of gas production remain a dominant preoccupation even up to 1990s. Emphasis on the energy aspect still dominates in many parts of the world today.

Cereals and pulses are the staple food in India, thus it has to be stored by producers in their homes and by traders and government agencies. Variations in the season i.e., warm and high humidity weather is highly conducive to proper development and rapid multiplication of storage insect pests. Almost all insect pests of stored grains have a remarkably high rate of multiplication and within one season, they may destroy 9-10% of the grains and contaminate the rest with undesirable odors and flavors. The type of insects infesting grains vary and include weevils, moths and beetles. Apart from this it is necessary to control or kill egg, larval, pupal and adult stages of the insect. After proper cleaning and drying the produce is stored where damage can be caused due to cross-infestation or infestation already left in the produce. Grains are stored in different types of receptacles and to protect it, different protectants are being used since from the early days. The success in the use of these protectants (organic, inorganic or inert) depends upon the effect on the grain, killing of the insects, practicability, period of storage and lastly the physical and chemical state of treated seeds.

1. Inert dusts

Inert dusts are fine powders chemically inactive but cause considerable insecticidal activity by mechanical abrassing and physical absorption of moisture proofing layers of insect integument. The use of inert dust was initiated sometimes during World War II. Some common inert dusts are ashes, clays, gypsum, lime, magnesite, Nakki, silica, talk, phosphates, diatomaceous earth. It was reported that though most of the dust proved effective and convenient to use but it is difficult to remove it and clean as it goes inside the infested and damaged grains. The dust can only kill larvae and adults moving in between the grains. Once any stage of insects entered inside the grain, it is beyond the reach of the dust.

India produce a wide range of tropical, subtropical and temperate horticultural crops at different places by virtue of its varietals agro- climate conditions. The total annual production of fruits and vegetables is around 135.5 million tones, fruits being 48 million tones and vegetables around 87.5 million tones. India is the second largest producer of fruits and vegetable in the world. They are major sources of important valuable vitamins and minerals. Being highly perishable, fruits and vegetables can be preserved and processed either at farm level or at cottage scale/home scale during market glut season or extra seasonal produce from kitchen garden for later use. Farmers and entrepreneurs can set up their own processing units by adopting simple, low cost innovative processing technologies which will save post harvest losses of these perishable crops and also give good returns to grower and better earning to processor/ entrepreneurs.

Agriculture shapes the foundation of Indian economy and despite the fact that there has been vast industrialization in most 60 years; horticulture still occupies a place of significance. In India, approximately 20-25% of the horticulture produce goes waste due to improper post harvest operations which reduces the growers share in the present marketing arrangements. The grower is getting hardly 25-35 paisa of a consumer rupee. The Value addition activities where the fruits and vegetables are processed, that fetches higher remunerative prices of the produce. Such opportunities are presently not available in rural areas but could be created through selective mechanization of agriculture and appropriate post harvest management and value addition to the harvested biomass in the production catchments.The agricultural produce involves operations like cleaning, grading, drying, storage, milling, packaging, transport, marketing and utilization. At the end of each operation, value is added to the product. The lowest and the highest monetary values of a food commodity are, respectively, when it is in raw and fresh form and when it is in processed and ready to consume/eat form. Post harvest and food processing technology are commodity and location specific. It prevent avoidable post harvest losses and adding value to the fresh agro-produces. It also creates opportunities for employment and income generation. Integration of production agriculture with on-farm primary processing is needed to have higher and sustainable production, productivity and better quality end products for domestic and export markets. It would help in reducing rural- urban disparity and ensuring household food and nutritional security for all at an affordable cost. The technology is available and a wide range of tools, machines and equipment are used in post-production of agriculture. The globalization of trade may compel many agro processing industries to rely on an imported technology at a high cost and the advantage of such technology may be availed by a few who have an exclusive business interest. Majority of agriculture-based enterprises will continue to depend upon indigenous technology and, therefore, R&D through public support has to be strengthened to become globally competitive and serve small-scale food processing sector of the country.

Most of the horticultural produce is of perishable nature and must be protected from postharvest losses, which start from the field itself. Therefore, adoption of proper packing house operation plays a very crucial role in minimizing postharvest losses

Although, we have reached new heights in the production of fruits comparable to China, Brazil and USA and in vegetables to China, yet we are far behind in postharvest management of these perishables, primarily due to lack of appropriate infrastructure. Test studies conducted in Australia have indicated that the distribution cost of perishable horticultural produce is assumed 5 to 9 times, the production cost. Further, packaging accounted for 25-50% of the wholesale price of fruits and vegetables. In India, huge losses of horticultural produce (25-30%) after harvest are encountered mainly due to non-existence of packing house concept.

Packing house operations essentially begins with the use of proper field containers, field transport, temperature protection of harvest produce, sorting, sizing, grading, packing, which are essential preparatory steps to storage, shipment and subsequent marketing. Depending on the kind of produce, additional activities viz. degreening, curing, washing, ripening, waxing, precooling etc. are done. The sequence of activities varies with the crops. A considerable quantity of postharvest losses of horticultural produce could be minimized by adoption of various packing house operations described below:

Honeybees are marvelous insects known to mankind since the prehistoric times. The art of their scientific management is called as apiculture or beekeeping and the place where hives are maintained is called apiary. Beekeeping is a decentralized, forest and rural agriculture based industry, which does not require any raw material. The raw material needed is in the form of nectar and pollen, which is freely available from flowers in nature. Bee hives neither demand additional land space nor do they compete with agriculture or animal husbandry for any input. The beekeeper only needs to spare a few hours in a week to look after his bee colonies. Beekeeping is therefore ideally suited to him as a part-time occupation. Beekeeping constitutes a source of sustainable income for the rural and tribal farmers. It also provides them valuable nutrition in the form of honey. However, in addition to honey, production of bees wax, propolis, pollen, royal jelly, pedigree queen bees, package bees and renting out honey bee colonies for crop pollination are some of the potential areas of apicultural diversification in India (TOI, 2012).

Mushrooms are fleshy fungi constituting a purely vegetarian diet, which is very tasty and nutritious. Some mushrooms are edible whereas others are poisonous. So far, more than 1600 types of mushrooms are known of which, nearly 100 have been accepted as food worldwide. Diversification in any farming system imparts sustainability. Mushrooms are one such component that not only impart diversification but also help in addressing the problems of quality food, health and environment related issues. One of the major areas that can contribute towards goal of conservation of natural resources as well as increased productivity is recycling of agro-wastes including agro-industrial waste. Utilising these wastes for growing mushrooms can enhance income and impart higher level of sustainability (Manjit Singh et al., 2011).

Mushroom cultivation activities can play an important role in supporting the local economy by contributing to subsistence food security, nutrition, generating additional employment and income through local, regional and national trade; and also offering opportunities for processing enterprises. Among the 33 globally cultivated types of mushrooms 3 mushrooms i.e. white button, oyster and paddy straw mushrooms are popularly grown in India.

Mechanization is viewed as package of technology to increase land productivity by improved timeliness of operations, reduced crop losses and improved quality of agro-produce to increase efficiency of inputs used through their efficient measurement and placement, to increase labour productivity by using labour saving and drudgery reducing devices and reduce cost of cultivation. echnology and machinery enhanced the ability, quality, accuracy and efficiency of the human being. By using technology in any field the rate production and quality automatically increases. The country witnessed unprecedented growth in agriculture which has helped India to graduate from hunger to self sufficiency in food grains by increasing the food grain production from 51 million tonnes to 208 million tones. The estimated contributions of improved agricultural tools and equipment in augmenting total food production of India is encouraging; savings in seeds: 15-20%; savings in fertilizers: 15-20%; savings in time: 20-30%; reduction in labour: 20-30%; increase in cropping intensity: 5-20%, and increase in productivity 10-15 per cent. The major issues before Indian agriculture with respect to mechanization are; tractorization vs mechanization, custom hiring and contract farming, horticultural mechanization, effective extension activity, sugarcane mechanization, hill agriculture and industry institution interaction. The main technologies which can be taken to farmers’ field for enhancing productivity and production Aqua-ferti seed drill, two row powered seeder, okra planter, tractor mounted inclined plate planter, tractor mounted rotary tiller (Rotavator), tractor mounted zero-till drill, tractor mounted raised bed planter, tractor mounted sett cutter planter for sugarcane, pneumatic planter, vegetable transplanter, low land manual rice seeder, self-propelled rice transplanted, self-propelled power weeder, tractor operated aero blast sprayer, tractor mounted vertical conveyor reaper, maize dehusker-cum-sheller, tractor operated straw reaper (combine) and tractor operated fodder harvester. These technologies need to be introduced after necessary modifications and adjustments, depending upon the agroclimatic and terrain and soil conditions, through proper mode e.g. as individual /group ownership, on custom hiring basis or mechanization package for contract farming.

Amongst agricultural commodities milk is the single largest contributor to gross value of output followed by paddy, wheat, oilseeds, pulse and sugar. It is not only that, milk is also least contributor to inflation.Thus it can be said that milk is the lifeline of Indian economy. Unlike developed countries, unique feature of Indian milk production system is that about 70% of it is produced in about 70 million household dairy units in rural areas.Dairy farming has always been a subsystem of agriculture in such household units which entirely depends on the recyclable crop residues. Moreover the milk production system has been mainly confined to landless labourers, small and marginal farmers.Their poor socioeconomic condition, religious sentiments for cattle and utilitarian attitude towards dairy farming coupled with poor milk production potential of dairy animals has remained a major impediment in the overall development of the system. Livestock is an important source of supplementary income. Mixed farming has been serving as an insurance against natural calamities, while supporting food security and nutrient recycling. India has over 500 million livestock, which include cattle, buffaloes, sheep and goats. Among them, cattle and buffaloes are popular for milk production. As milk is an important part of the Indian diet and bullock power is essential as draft animal for farming and rural transportation.

India is emerging as a global economic power and the economy is growing at an average of 8 9 per cent for last couple of years.The Dairy sector is contributing significantly to the national economy and with 112 Million Metric Tonns (MMT) milk productions during 200910; it ranks first in the World. It provides gainful employment and supplementary income to large number of people. Dairy sector contribute significantly on poverty reduction in rural areas as income from milk in the total income of underprivileged family is as high as 75 to 80% during drought and the employment generated is relatively high. Dairying has become an important secondary source of income for millions of rural families and has assumed an important role in providing employment and income generating opportunities.

India is endowed with 8118 kilometers of coastline and access to 5.3 lakh square kilometers of continental shelf to facilitate marine fishing.195210 kilometers long river and canal system, more than 6 million hectares of water bodies under reservoirs, ponds, Fish is an integral part of food and culture in India. Indian coastal region is rich in aquatic bio diversity with various identified fish species and also in aquatic resources. India with its vast and varied marine and inland resources stands third in world total fish production and second in inland fish production. India’s fish production has increased from 5.6 million tonne during 2000-2001 to 6.9 million tonne during 2006-2007. During the year 2006-07, the country witnessed foreign exchange of Rs.8363.53 crore through export of sea food. Fish processing industries in India are gaining importance in recent years due to increase in demand of processed food by the developed countries. In India fishery sector provide livelihood to an estimated 10 million people and the Inland fisheries are of particular importance to the rural poor accounting for about 15% of total global employment (FAO, 2000). Sustainable utilization of available resources with appropriate farming system approaches will increase fish production and also will generate employment opportunities.

Lac insect is an insect of commercial importance like silk worm and honey bee. The silkworm produces silk, honeybee produces honey and wax whereas, lac insect produces three products namely resin, dye and wax of great commercial importance. The resin commonly called lac, is only one of animal origin and commercially available in the market as shellac or seed lac or as a button lac. The resin is in fact the hardened secretory product of lac insect secreted as a protective covering of an insect. Lac culture is one of the important sources of livelihood and rural economy for poor resource constraint people particularly inhabiting in forest and sub-forest areas. It is one of the important sources of livelihood security in many parts of the country in states like Jharkhand, Chhattisgarh, Madhya Pradesh, West Bengal, Odisha, Maharashtra, Madhya Pradesh, Uttar Pradesh, Assam, NE regions etc (Pal et al., 2007). It has also high potential for generating employment for both men and women in forest and sub-forest areas of the country. It is a very remunerative crop, paying high economic returns to the farmers and also foreign exchange for the country through its export.

Introduction

Three hundred million poor people in Asia depend on livestock for their livelihoods and there are opportunities for improvement in livestock related livelihoods due to the rapid and dynamic changes that the livestock sector in Asia is undergoing (Njuki et al. 2010). Piggery farming has been recognized as one of the profitable venture among the rural masses. This venture has proved to be one of the most important livelihood option. Generally the pigs are reared for pork, considering the increasing trend of pork consumers in India; Piggery farming will certainly take a industrial form of livelihood in India in future. There are more than 12.8 million pigs in our country, out of which approximately 14.5% are graded and of exotic variety. There are 120 pig breeding farms in the country whereas pigs of exotic breeds are maintained. China ranks first in the world in pig rearing where number is around 300 million or 1/3 of the world pig population.Pig production is basically an enterprise which is able to convert inedible or inferior quality food into the food rich in animal protein. Pig is considered a machine because they convert grain, pasture and other low quality feed into Pork which is used as human food (Rahman, 2008) . Despite the fact that pig rearing is a profitable enterprise most of the progressive farmers even today hesitate to adopt it due to prejudice sentiments in our society against pig farming. For many others there is religious taboo against pig. A majority of meat eaters also and cheap source of protein. Pork as a source of animal protein is gaining popularity in India and pork products will be in greater demands in years to come. The high carcass yield attracts the farmers because of the better returns within the shortest possible time. High fertility in pigs assumes income to the rearer round the year. To bring about improvement in the productivity of pork and other piggery products extensive crossbreeding programme has been taken up to develop animals of large size, better feed conversion efficiency, high dressing percentage and better quality pork. Pig keeping also contributes to socio-cultural obligations and risk diversification and converts existing resources and low value waste products into high-value animal source food for home consumption and/or sale (NEPED, 2008).

Goat is the 1st domesticated animal in the ancient age and has been considered to be the Poor Man’s Cow Goat’s meat is lean & has low fat and the demand for goat’s meat is increasing, with rising prices. Goats usually give birth to twins & triplets. Goat is a multi functional animal and plays a significant role in the economy and nutrition of landless, small and marginal farmers in the country. Goat rearing is an enterprise which has been practiced by a large section of population in rural areas. It can efficiently survive on available shrubs and trees in adverse harsh environment in low fertility lands where no other crop can be grown. In pastoral and agricultural subsistence societies in India, goats are kept as a source of additional income for their meat, hair fiber, and dairy, or as a pet. Goats are also used in ceremonial feastings and for the payment of social dues. According to FAO (2008) goat milk production in India were 4 million metric tons, Bangladesh 2.16 million metric tons and the Sudan 1.47 million metric tons over much of the world. Goats are among the main meat-producing animals in India, whose meat (chevon) is one of the choicest meats and has huge domestic demand (Shalander Kumar, 2007). Goat rearing is an enterprise which has been practiced by a large section of population in rural areas. Goats can efficiently survive on available shrubs and trees in adverse harsh environment in low fertility lands where no other crop can be grown. (Oberoi et al., 199I) reported that in variable cost, expenditure on labour was the major component of cost and was 81% under goat farming.

1. Introduction

2. Human Genome Project

3. Development of Bioinformatics

3.1. Indian scenario

4. Plant Genome Model

5. Components of Plant Genome Database

5.1. Stock centre databases

5.2. Genome mapping database

5.3. DNA sequences

6. Agricultural Research Service and National Research Initiative

6.1. Objectives of plant genome programme

6.2. GIBN Trans – pacific digital library experiment plant genome databases

7. Plant Genome Databases

7.1. Vegetable genome databases

7.1.1 Mendel-Plant Gene Nomenclature Database

7.2. Others

7.2.1. Bean Genes – Phaseolus / Vigna sp. Database

7.2.2. Solgenes Database

7.2.3. Soybase

7.3. Other data bases

7.3.1. PGDB (Pathway genome data base)

7.3.2. Demeter’s genome

8. Tools of Bioinformatics

9. New Directions in Genome Database at Stanford

10. Navigating the World Wide Web

11. Virtual Genome Centre (VGC)

11.1. Programmes at the VGC

12. Impact of Gene Chips and Micro Arrays

13. Applications and Impacts

14. Bottlenecks

15. Future Thrust

1. INTRODUCTION

Today’s technological advancement have reached a level where a farmer can have access to information and tools to manage his mechanized field operations. They can now measure, evaluate and deal variability with infield (e.g. soil fertility, water availability and yield) that was known to exist previously but was not manageable, to his advantage. The ability to handle variations in productivity within a field and maximize financial return, reduce waste and minimize impact on the environment has always been the objective of an enterprising farmer, especially those with limited land resources and those who advocate sound agriculture practice.

This concept is not new. What is new is the ability to automate data collection and documentation and the utilisation of this information for strategic farm management decision in the field operations through mechanisation, sensing and communication technology. Such an approach in agriculture production management gives rise to what is now termed as Precision Farming (PF), Precision Agriculture (PA), Prescription Farming (Precision farming), Site Specific Agriculture (SSA), Soil Specific Crop Management (SSCM), Spatially Variable Crop Production (SVCP) etc.

1. INTRODUCTION

The basic principle of plant breeding is the utilization of existing variation and creation of new variations. Ploidy breeding is one of the tools used for improving the crop plants. The year 1937 can be considered as a landmark in the history of plant breeding. The discovery of the specific action of colchicine in inducing polyploidy has provided the breeder with a means for increasing the scope of crop improvement apart from the removal of the barrier of sterility in the sterile interspecific hybrids by the production of amphidiploids and their utilization later for the transfer of useful genes from the wild parents to cultivated plants. It was hoped that the production of autoploids in various crop plants would directly lead to the cultivation of better plants, as generally the autopolyploids are known for their gigas characters including the seed.

1. INTRODUCTION

‘Fertigation’ is the technique of supplying dissolved fertilizer to crops through an irrigation system (Haynes, 1985). When efficient irrigation system combined with both nutrients and water, it can lead to obtain higher yield and preferable quality desired marketable produce.

Often, side-dressings of straight solid fertilizers are found to be the management constraints. Most of the growers have the experience of how much the applied fertilizer is either washed from the soil in run-off or leached below the root zone.

Continuous small applications of soluble nutrients have the benefits like labour, due to fertilizer being placed uniformly around the plant roots and allow savings/economy rapid uptake of nutrients by the plant.

1. INTRODUCTION

India is traditionally rich on agricultural knowledge. Presently modern farming is not sustainable in consonance with economics, ecology, equity, energy and socio–cultural dimensions. Indiscriminate use of chemical fertilizers, herbicides and pesticides to boost the yields have resulted in various environmental and health hazards along with socio–economic problems. The agricultural production has continued to increase, but the trend in productivity has started declining. The agricultural scientist’s and farming community whole heartedly aim at an alternative sustainable farming system which will be ecologically sound, economically viable and socially acceptable. The answer to the problem lies in refining our own traditional practices based on natural and organic farming methods offering several safe, feasible and cost effective solutions.

The term ‘Organic farming’, a system of farming is one which avoids synthetic fertilizers but rely upon crop rotation also using crop residues, animal manures, legumes, green manures, biofertilizers, organic wastes etc., to maintain the soil fertility and increase productivity. This system enables the nutrients leaching from perennial wood and vegetation and help to maintain organic matter and protect the soil from surface erosion. The world wide awareness for adopting organic farming has paved way for streamlining the production technology and certification by adopting the specified crop production practices. Organic farming practices in agriculture and animal husbandry are native to East Asian countries, like India and China. In China a strong national movement for animal waste recycling is in vogue, minimizing the use of inorganic fertilizers (Xu, 2000), while in our country specific crop production practices are developed in isolation and adopted locally.

The trend of use of chemicals and industrial inputs in intensive farming is increasing which resulted in soil health deterioration and increased environmental pollution which causes a great concern all over the world. Therefore an emphasis on the need to use the organics and other byproducts of agriculture and industry is emerging. Fortunately, the country is already rich with left over crop residues (185 million tonnes) but its use presently is limited. Apart from crop residues, there is an enormous quantity of cattle wastes out of which sixty per cent of the used for fuel purpose in rural areas.

1. INTRODUCTION

Organic farming systems can deliver agronomic and environmental benefits both through the structural changes and the tactical daily management of the farming system. The benefits of organic farming systems are relevant both to developing and developed nations which helps for environmental protection, biodiversity enhancement, reduced energy use and CO₂ emissions (Thiyagarajan, et al., 2003). The post Green Revolution era has led to environmental pollution due to excessive use of agrochemicals and fertilizers and thus threatened the fragile ecosystem (Selvaraj et al., 2001). Organic farming conserves soil fertility and curtails soil erosion through implementation of appropriate conservation principles (Thampan, 1995). Organic farming leads to live in harmony with nature.

United Nation experts indicate that organic foods have the good opportunities for developing countries to open a space in the global market. This entails the creation of greater awareness of trade opportunities for organic products as well as of the environmental, economic and social benefits to the public.

1. INTRODUCTION

The numbers of plant products that influence the nervous system are many and particular group that act on central nervous system by influencing neurotransmitters or endorphins are treated as psychoactive plants. Psychoactive drugs that act on the central nervous system are very much involved in psychiatry. The range of effect is wide for these plants and they can be divided into three categories viz.,

• Stimulants, which excite and enhance psycho motor activity.
• Depressants which reduce mental and physical performance and
• Hallucinogens which are capable of inducing dream like state.

A wide range of plant derivatives are involved in these mind altering drugs.

1. INTRODUCTION

Many food components are encapsulated and stabilized by nature inside plant cells, but, with the growth in use of functional ingredients and product fortification with vitamins, antioxidants and nature-identical synthetic compounds, there is a need to stabilize and protect these ingredients from the rigours of processing and degradation during storage.

Many food products whose development was thought to be technically unfeasible are possible today because of the wide availability of encapsulated ingredients. Such ingredients are products of a process that totally envelops the ingredient in a coating or ‘capsule’ thereby conferring many useful and otherwise unusual properties to the original ingredients.

Encapsulation is a technique that is applied to preserve and/or protect numerous ingredients. In the flavour industry, the encapsulation process is used chiefly to convert liquid flavour materials to free-flowing, dried powdered products. In a broad sense, encapsulation technology includes the coating of minute particles of ingredients (e.g., acidulants, fats, and flavours) as well as whole ingredients (raisins, nuts, and confectionery products) that may be accomplished by microencapsulation and macro-coating techniques, respectively.

1. INTRODUCTION

The terms antioxidants and free radicals are being very effective used nutritionists and other health professionals. Antioxidants are compounds are good for health and free radicals are harmful. In general, antioxidants neutralize free radicals that are generated in the body and prevent damage to cell proteins, lipids and carbohydrates. Antioxidants can be water-soluble or lipid-soluble, thus they exist within the lipid or within the water portion of cells. Antioxidants are substances when present in food or in body at low concentration retards or prevents undesirable oxidation of substrates by free radicals.

Within the human body, millions of processes are occurring at all times. All cells require oxygen to generate energy; higher eukaryotic organisms cannot exist without oxygen. Unfortunately, that same life giving oxygen can create harmful side effects which cause cell damage and lead to chronic disease. Damage caused by free radicals is called oxidation. Oxidative stress is the disturbance in the prooxidant-antioxidant balance in favour of the former, leading to the potential damage.

1. INTRODUCTION

Micropropagation is a specific aspect of plant tissue culture dealing with the aseptic vegetative multiplication of plants in-vitro and is divided into several major stages:

Stage 0: Stock plant selection and preparation

Stage 1: Initiation and establishment of an aseptic culture

Stage 2: Multiplication

Stage 3: In-vitro rooting and conditioning

Stage 4: Acclimatization to ex-vitro environment. (Hartmann et al., 1990)

1. INTRODUCTION

Plant diseases are major constraints to plant growth and development (from seed to maturity) resulting in crop losses. Plants are exposed to attack, by a wide variety of microbes like bacteria, virus, fungi, phytoplasma and as an abnormality they cause disease. To counter these threats, plants have evolved a series of defense systems in response to the pathogen challenge inhibiting natural resistance. Thus disease is an exception rather than rule. However on failure of the inbuilt resistance mechanism, outbreak of disease has led to the widespread use of chemicals that have deleterious environmental and human health consequences. To enable the development of more effective and durable resistance against pathogens, a detailed analysis is necessary to identify the genes and mechanisms involved in plant defense/resistance.

Recombinant DNA and gene transformation technologies have potential to augment traditional breeding efforts (limited by genetic variability) by circumventing taxonomic limitations to gene pool for pathogen resistance. Further manipulation of defense genes in transgenic plants provide novel approaches for engineering pathogen resistance. It becomes important to understand the different components of plant defense to exploit host plants for resistance Thus the review is focused on plant genes and proteins that are known to play a major role in plant resistant against pathogens.

1. INTRODUCTION

Plants produce an array of natural products, the secondary metabolites, which play a variety of roles such as pollinator attractants e.g. pigments and scents and defense molecules against attacks by animals and microorganisms. These substances are very much important as a source of pharmaceuticals, fragrances, agrochemicals and food additives. Great efforts have been made by the chemical industry to mimic and synthesise these compounds. However little success has been achieved and plants still remain the major source of these vital compounds (Wink, 1990). In the late 1970s plant cell culture was thought to be an alternative or additional way of producing these compounds (Alfermann and Peterson, 1995). The low yields obtained with cultured cells and inferior to the amounts present in intact plants, provided a major drawback to their commercial exploitation. The plant derived pharmaceuticals represent a large market value; about 25% of today’s pharmaceuticals contain at least one active ingredient of plant origin. So only a minute fraction of the enormous biosynthetic potential of plant cells is being exploited. The most popular analgesic drug aspirin and the most valuable anti-cancer drugs paclitaxel and vinblastine are derived solely from plant sources (Pezzuto, 1996).

Over the last 10-15 years, the successful genetic transformation of plants has been reported in about 200 species including agricultural crops, trees, ornamentals, fruits and vegetables. Such genetic modification has improved specific crop traits, such as resistance to pathogens, to herbicides and to various environmental factors including drought and floods (Bajaj and Ishimaru, 1999). Following on from this success genetic transformation of medicinal plants has been attempted, primarily to enhance the production of various pharmaceuticals, flavours and pigments. During the early 90’s it was suggested that metabolic engineering of biosynthetic networks might be achieved by application of recombinant DNA methods.

1. INTRODUCTION

The Technology Protection System (TPS) or “Terminator Technology” as it has been called, allows plant breeders to genetically modify and protect their crop rights so they produce seed for one generation only. TPS was co-developed by the US Department of Agriculture (USDA) and Delta and Pine Land Company in 1998. They received U.S. Patent 5723765 entitled “Control of Plant Gene Expression”. The patent was based on research conducted under a Cooperative Research and Development Agreement (CRADA) between Delta and Pine Land Co. and the ARS USDA. The CRADA was signed in 1993.

1. INTRODUCTION

The past hundred and fifty years of this millennium have witnessed an unbelievable pace of scientific and technological development. Modern science has attempted to a great extent and succeeded in realizing the dreams and fantasies of philosophers and scientists of the previous centuries. Plant genetic engineering via., nucleus is a mature technology that has been used productively for research and commercial applications. However, plants have an unassuming second genome inside the tiny organelles called as plastids. Although this small circular DNA carries a fewer genes than its nuclear counterpart, researchers say its potential for genetic engineering far outstrips its size. The ability to introduce foreign genes at specific locations on a chloroplast has been acquired very recently. It is expected that certain limitations of nuclear genome transformation methods in terms of protein expression and environmental safety can be overcome by site-specific introduction of genes into plastids. Thus the plastid engineering forms a viable alternative serving as another milestone in the field of plant biotechnology.

1. INTRODUCTION

Vegetables play a significant role in human nutrition, especially as sources of vitamins, minerals, dietary fibre and antioxidants. Consumption of vegetables on a daily basis is highly recommended because of its associated health benefits, which include reduced risk of chronic diseases.

Due to perishable nature of vegetables, the post harvest losses of these commodities are four to five times higher than those of food grains. The post harvest losses from vegetables accounts to a tune of Rs. 23,000 crores per year. Both quantitative and qualitative losses occur in horticultural commodities between harvest and consumption. Qualitative losses, such as palatability, nutritional quality, caloric value and consumer acceptability of fresh produce, are much more difficult to assess than the quantitative losses.

Postharvest losses vary greatly across commodity types, with area and the season of production. In contrast, the range of produce losses in developing countries varies widely. Losses at the retail, food service and consumer levels are estimated at approximately 20 per cent in developed countries and about 10 per cent in developing countries. Overall, about one third of horticultural crops produced are never consumed by humans. Reduction of post-harvest losses can increase food availability to the growing world population, decrease the area needed for production and conserve the natural resources.

The Total Horticulture production of the country is estimated to be an impressive level of 314.87 Million Tonnes during 2018–19.

Production of fruits is estimated to be about 97.38 million tonnes during 2018–2019.

Production of vegetables is estimated to be about 187.36 million tonnes during 2018–2019.

Production of spices is estimated to be about 8.61 million tonnes during 2018–2019.

Plantation crops are another potential sector with lot of opportunities for employment generation, foreign exchange earnings and overall supporting livelihood sustenance of mankind at large.

In short and sweet horticulture supplies quality food for health and mind, more calories per unit area, develops better resources and yields higher returns per unit area.

It also enhances land value and creates better purchasing power for those who are engaged in this industry. Therefore, horticulture is important for health, wealth, hygiene and happiness.

Similar to forest trees these horticultural trees will maintain the ecosphere. They help in transforming the micro climate.

It provides shelter to birds, reptiles and other micro organisms and add to the geo–ecological diversity on the land.

The Indian subcontinent is bestowed with a great variety of climate and soil conditions.

• Broadly the country can be divided into Tropical, subtropical and temperate regions.
• Within each broad category there are differences due to rainfall, humidity, altitude etc.
• Considering these aspects six different horticultural zones have been identified so that appropriate choice of the crops can be made and development is planned. They are;
• Temperate: Kashmir, Himachal Pradesh, North Uttarakhand, Sikkim and part of Arunachal Pradesh.
• N.W. Subtropical: Punjab, Haryana, Rajasthan, Central Uttar Pradesh and North M.P.
• N.E. Subtropical: Bihar, Jharkhand, Assam, Meghalaya, Nagaland, Manipur.
• Central tropical: South Madhya Pradesh, Chattisgarh, Gujarat, Maharashtra, Orissa and West Bengal.
• Southern tropical: Karnataka, Andhra Pradesh and Tamil Nadu.
• Coastal tropical humid: Konkan, Goa, Kerala, Western Ghats, Eastern Ghats in Tamil Nadu, Andhra Pradesh and Orissa.