eChapters

Introduction

The original concept of feeding bacterial direct fed microbial (DFM) to livestock was based primarily on potential post–ruminal effects, including improved establishment of beneficial gut microflora (Fuller, 1999). Calves fed Lactobacillus acidophilus have been reported to have reduced incidence of diarrhoea (Beecham et al., 1977) and reduced intestinal coli form count (Bruce et al., 1979). But now it is known that certain bacterial DFM also have beneficial effects in the rumen and one of the important groups of this type of bacteria is propionic acid producing bacteria (Elsden, 1945; Johns, 1951a; Langa, 2010). This group of bacteria includes Propionibacterium spp., Veillonella spp., Megasphaera spp., Selenomonas spp. and Succiniclasticum spp. (Table 1). Propionic acid producing bacteria (PAPB) are secondary bacteria which enhance propionate production by utilizing the end products of primary fibrolytic or starch utilizing bacteria which produce succinic acid and lactic acid (Swenson and Reece, 1996). Inoculation of in vitro fermentation with the lactate utilizing ruminal bacterium Megasphaera elsdenii prevented lactate accumulation and produced propionic acid when a highly fermentable substrate was used (Kung and Hession, 1995). Propionibacteria are also rumen active bacteria which can produce propionic acid by utilizing glucose, lactic acid and succinic acid (Elsden, 1945; Grinstead and Barefoot, 1992; Hugenholtz et al., 2002). Ghorbani et al. (2002) also reported that Propionibacteria convert lactate and glucose to acetate, propionate and CO₂. They also reduce nitrate to nitrite and reduce nitrite load by 40-60% and minimize changes in blood nitrite and met hemoglobin (Rehberger et al., 1993). Succinic acid is an important end–product, but in practice this is converted into propionic acid by other bacteria such as Selenomonas ruminantium (Swenson and Reece, 1996; McDonald et al., 2002; Langa, 2010); such interactions between microorganisms are an important feature of rumen fermentation. Veillonella gazogenes are also active in the rumen and produce propionic acid by fermenting succinic acid (Johns, 1951a). Moreover in low quality forage-based diet Fibrobacter succinogenes are predominant fibrolytic bacteria which digest fibre faster and produce sufficient amounts of succinic acid in the rumen (Cheng et al., 1984; Miron and Ben-Ghedalia., 1992) and synergistic increases in propionate production and fiber digestion was found in co-cultures of Fibrobacter succinogenes and Selenomonas ruminantium (Sawanon et al,2003), and of Ruminococcus flavefaciens and Selenomonas ruminantium (Sawanon et al., 2006). These findings suggest that positive interactions occur between bacteria, mostly via metabolite exchange.

Introduction

The process of making the rumen of animals free of rumen protozoa is called defaunation and the animal is called defaunated animal. The role of rumen ciliate protozoa on the performance of host animals became debatable issue when Becker and Everett (1930) demonstrated that rumen protozoa were non-essential for growth in lambs. Nevertheless, the reports of recent years reflect that though protozoa may be non essential for ruminant, still they have significant role to play in the rumen metabolism specially to stabilize the rumen pH (Santra and Karim, 2002a). Rumen protozoa are the largest in size among rumen microbes and contribute 40-50% of the total microbial biomass and enzyme activities in the rumen (Agarwal et al., 1991).

Introduction

Enzymes are globular proteins that act as biological catalysts. They are produced by living cells to bring about specific biochemical reactions. Digestive enzymes catalyze the degradative reactions by which substrates (i.e., feedstuffs) are digested into their chemical components (e.g., simple sugars, amino acids, fatty acids) which in turn, are used for different body functions. Different enzymes are utilized for the complete digestion of complex feed. The enzymes are being used in the feeding industry from last several decades. Various digestive enzymes have been studied for use as feed additives to enhance animal performance They are commonly used to improve the nutritive value of feeds for non-ruminants (especially, poultry and swine). They are not routinely used in adult ruminant diets because the fibrolytic activity within the rumen environment is normally very high, and it is assumed that exogenous enzymes cannot survive proteolysis in the rumen (Kopency et al., 1987). Forages are the main feed component that serve as the major source of energy available to the animal in ruminant production system. However, due to slow or incomplete digestion of fibrous substrates only 10 to 35% of energy intake is available as net energy that significantly limits livestock performance and profits in production systems. To improve the ruminal fibre degradability many strategies have been developed to stimulate the digestion of the fibrous components in ruminant feeds. That includes, use of various feed additives which stimulates fiber digestion, physical and chemical processing of feeds in order to enhance the rate and extent of fiber digestion. However, the use of “natural” product to enhance production efficiency is highly recommended that can potentially play some role in replacing performance benefits vacated by antibiotics and hormones. Enzymes are proteins that are ultimately digested or excreted by the animal, leaving no residues in products, which was a major drawback in the use of antibiotics and hormones.

Introduction

While world population is expected to increase from 6 billion to about 8.3 billion, India is likely to be the most populous nation with 1.6 billion in the year 2030. Therefore, it is essential to be prepared to produce sufficient food for the increased population with the application of newer technologies. The consumption of animal food was 10 kg/yr in the 1960s increasing to 26 kg/yr in 2000 and is expected to be 37 kg/yr by 2030 (FAO, 2008; 2009). Large increases in per capita and total demand for meat, milk and eggs are forecast for most developing countries for the next few decades (Delgado et al., 1999). In developed countries, per capita intakes are forecast to change slightly, but the increases in developing countries, with their larger populations and more rapid population growth rates, will generate a very large increase in global demand.

Moreover, an increasing number of consumers demanding healthy and quality foods have pushed researchers into development of technologies that can control the proportion of lean and fat muscle deposition in meat producing animals. A number of technologies have been developed that led to remarkable improvements in the efficiency of animal production and in carcass composition and meat quality. There are some dietary additives and vitamins that may increase protein and muscle deposition, while often simultaneously reducing fat deposition by modifying nutrient metabolism in individuals.

Introduction

For raising animal and its products especially protein, food and nutrition plays an important role. Feed cost comprises about 60% of total recurring expenditure. Feed additives play an increasingly important role in animal nutrition by augmenting the performance by maintaining the needs of essential nutrients, improving feed conversion therefore optimize feed utilization (Wenk, 2000). Feed additives are a group of feed ingredients that can cause a desired animal response in a non-nutrient role, such as rumen modifier, growth or metabolic modifier (Hutjens, 1991). These are used in micro quantities and require careful handling and mixing. The development and introduction of various new feed additives is a major and practical solution to improve the efficiency of animal production, to alleviate environmental pollution, to maintain animal health, welfare and to ensure the safe and of good quality food production.

Introduction

Growth enhancement technologies have been widely embraced in the livestock industry to improve growth, efficiency and carcass traits. For over 50 years, estrogenic and androgenic hormone implants were widely used in the cattle feeding industry, and it is estimated that approximately 97 percent of feedlot cattle in the U.S. receive one or more implants during the finishing phase (Barham et al., 2003; Tatum, 2006). There is a large body of literature that indicates the positive growth enhancement effects which implants impart on growing and finishing cattle and producers have extensively used implants to increase live body weight, improve average daily gain and feed efficiency, and reduce the number of days cattle are on feed (Apple et al., 1991; Duckett et al., 1997;Milton and Horton, 1996; Perry et al., 1991). Likewise, there is a growing body of literature that indicates the positive response on growth and carcass characteristics that finishing cattle have to beta-adrenergic agonists. The hog industry, and more recently, the cattle feeding industry have increased utilization of beta-adrenergic agonists to improve the efficiency of production. While the use of Ractopamine hydrochloride (Paylean^®, Elanco Animal Health, Greenfield, Indiana) has been used extensively in hog production since its approval by the Food and Drug Administration (FDA) in 1999, similar pharmaceutical feed additives have only recently been implemented in commercial cattle feeding operations. Beta-adrenergic agonist use in fed cattle has substantially increased following the FDA approval of Ractopamine hydrochloride (Optaflexx^®, Elanco Animal Health, Greenfield, Indiana) in 2003, and the approval of Zilpaterol hydrochloride (Zilmax^®, Merck Animal Health, Summit, New Jersey) in 2006. The use of both Ractopamine hydrochloride (RH) and Zilpaterol hydrochloride (ZH) have shown to elicit similar improvements in live weight gain, average daily gain, and feed efficiency as those reported in hormone implants (Allen et al., 2009; Avendano-Reyes et al., 2006; Beckett et al., 2009; Elam et al., 2009; Gruber et al., 2007; Kellermeier et al., 2009; Scramlin et al., 2010). In addition, these compounds have been reported to have profound effects on hot carcass weight, Longissimus muscle area and carcass cutability (Gruber et al., 2007; Hilton et al., 2010; Rathmann et al., 2009; Scramlin et al., 2010; Shook et al., 2009; Vogel et al., 2009). It is because of this that cattle feeders have drastically increased use of beta-agonists since their FDA approval, and a growing portion of the fed cattle population receive a dietary beta-agonist supplement that is provided within the final 20 to 30 days of finishing.

Introduction

Supplementary feeding is an essential practice in fish farming operation which accounts for over 60% in total input cost. The dependence of candidate species on balanced supplementary feed increases with increase in stocking population in ponds targeting per hectare higher production as the standing crop of cultured species exceeds the natural feeding capacity of ponds. Therefore, feeding of artificial feed balanced in all nutrients such as protein, lipid, carbohydrate, vitamins and minerals containing optimum protein and energy ratio has assumed foremost importance in aquaculture industry. The use of balanced feed however, is directed towards optimum realization of genetic potentials of farmed species for survival, immunity, growth and reproduction (Mohanty, 2009). Consequent to researches done in India and abroad, a strong data base has been developed about the nutritional behavior of great majority of these cultivable fish and shell fish species and several feed formulations have been successfully undertaken. With optimum pond management, feeding of formulated balanced feed, it has been possible to increase aquaculture production as high as 15- 17 t/ha/yr for carps and 8-12 t/ha/yr in semi intensive prawn and shrimp farming in India (Mohanty, 2009).

Introduction

Public concern over use of antibiotics in livestock production has increased in recent years because of their possible contribution to emergence of antibiotic resistant bacteria, and their transmission from livestock to humans. Accordingly, ruminant microbiologists and nutritionists have been exploring alternative methods of favorably altering ruminal metabolism to improve feed efficiency and animal productivity. Plant extracts contain secondary metabolites, such as essential oils (EO) that have antimicrobial properties that make them potential alternatives to antibiotics to manipulate microbial activity in the rumen. Essential oils are naturally occurring volatile components responsible for giving plants and spices their characteristic essence and color. Over the last few years, a number of studies have examined effects of EO, and their active components, on rumen microbial fermentation. However, many of these studies are laboratory based (i.e., in vitro) and of a short-term nature. Nevertheless, results from in vitro batch culture studies provide evidence that EO and their components have the potential to improve N and/or energy utilization in ruminants. Effects of EO on ruminal N metabolism is more likely mediated by their impact on hyper-ammonia producing (HAP) bacteria resulting in reduced deamination of amino acids (AA) and production of ammonia N.

Introduction

Plant products have been used for centuries by humans as food and to treat ailments. Natural medicinal products originating from herbs and spices have also been used as feed additives for farm animals in ancient cultures for the same length of time. Keeping farm animals healthy is necessary to obtain healthy animal products. The main scope in animal husbandry is to ensure good performance of farm animals and get quality animal products, which can be achieved only with the effort to keep the animals healthy. Only quality feed together with proper hygiene, potable water and management can ensure the production of nutritious animal products with desired organoleptic properties (Saxena, 2008). A ban of antibiotics as feed additives in animal nutrition is realized since 1986 in Sweden and later on to various countries. A general ban is foreseen in some years from now, because of the increased occurrence of pathogens resistant against therapeutical antibiotics used in animals and humans. With the restricted use or ban of dietary antimicrobial agents we must explore new ways to improve and protect the health status of farm animals, to guarantee animal performance and to increase nutrient availability (Wenk, 2003). In this aspect, herbs and spices are not just appetite and digestion stimulants, but can, with impact on other physiological functions, help to ensure good health and welfare of the animals, what can positively affect their performance.

Introduction

Mycotoxins are substances produced by fungal infections which in some cases do protect plants or plant seeds against parasites (Schardl et al., 1996). However, upon ingestion, inhalation or dermal contact, these mold producing substances are poisonous to vertebrates. Even with more than 100,000 species of fungi known, only some of them are active mycotoxin producers. The fungi species which are known to produce the most hazardous mycotoxins in agriculture and in animal production are Fusarium, Aspergillus and Pencillium spp. Mycotoxins vary greatly regarding their toxicological effects as they do not belong to a single class of chemical compounds (Jewers, 1987). The environmental conditions in which they are preferably produced also differ. Fusarium toxins, such as trichothecenes, Zearalenone and fumonisins are commonly produced on the field, whereas aflatoxins and ochratoxins are produced by Aspergillus and Penicillium spp. mainly after harvest and during poor storage conditions.

Introduction

Plant pests have been a part of the man’s environment, since ages. Traditional agriculture which included diverse crops and indigenous crop management practices provided little opportunity for the pests to build up and spread rapidly (Smith and Allen,1954). Crop production is constantly threatened by increasing difficulties in controlling insect pests, which are a major impediment to improved livelihoods of the poor farmers. However, in the quest for increasing food production for the growing population, use of pesticides became a norm in crop management. Pesticides became an integral part of the process owing to losses from weeds, diseases and pests reducing the harvestable produce. Use of pesticides along with high yielding varieties, irrigation and improved seed did result in increased productivity. But the rampant use of these chemicals, under the adage, “if little is good, a lot more will be better” has played havoc with human and other life forms.

Introduction

Integrated Pest Management (IPM) has evolved over the last five decades since Stern et al. (1959) first gave the concept of integrated control. The basic tactics of IPM were developed and applied to reduce crop losses against the ravages of pests before the term IPM was coined (Jones, 1973; Smith et al.,1973). Entomologist at the university of California, United State of America (USA) played a pivotal role in developing IPM tactics (Perkins, 1982). Development of resistance to insecticides and the elimination of natural enemies by insecticides led to the development of ‘supervised control’. The publication of the book ‘Silent Spring’ written by Rachel Carson (1962) was a defining milestone for it brought the problems caused by pesticides to the attention of the public and the scientists. The term ‘integrated pest management’ was used for the first time by Smith and van dan Bosch (1967). In the last five decade many synthetic pesticides have been banned. In 1972, ’integrated pest management’ and its synonym were incorporated into English dictionary and accepted by the scientific community (Kogan, 1998). IPM is the main strategy accepted for pest management under agenda 21 of the United Nations conference on Environment and Development (UNCED, 1992).

Agriculture has always played and will continue to play a dominant role in the growth of Indian economy in the foreseeable future. It represents the largest sector producing around 28 per cent of the gross domestic product (GDP). Achieving self sufficiency in food grains production has ensured a high priority for agricultural sector in the successive development plans of the country. Agricultural production is grossly affected by attack of pests/diseases on various crops and the losses in food grains only are to the tune of Rs 90,000 crores each year in India. The prevention of such losses needs substantial consideration and accordingly forewarning of pests and diseases is essential for taking timely control measures. These are also required for assessing losses. Pest/disease infestation in crops is highly influenced by meteorological factors. The weather based modeling for early warning of pest/disease infestation may provide appropriate tool for investigating and predicting pest/disease status.

The steadily-increasing human population has led to a rise in the demand for food. As more land comes under agricultural cultivation there will be more pressure on natural ecosystems. Climate change will affect agricultural yield directly because of aberrations in temperature and rainfall, and indirectly through changes in soil quality, pests and diseases. In particular, the yield of cereals is expected to decline in India, Africa, and the Middle East. As the temperature rises conditions will become more favourable for pests such as grasshoppers to complete a number of reproduction cycles and thereby increasing their population. In the higher latitudes (in the northern countries) agriculture will benefit with the rise in temperature as the winter season will be shorter and the growing seasons longer. This will also mean that pests that will move towards the higher latitudes as the temperatures rise. Extreme weather conditions such as high temperature, heavy rainfall, floods, droughts, etc. will also affect crop production.

Introduction

Information technology is set to become important in agriculture in the coming years. In the last few decades, the application of computers and communication technologies has led to the development of a plethora of information of all types in the area of plant protection science. These information bases are available on CD-ROM, on-line form in various hosts and via mail over internet, multimedia data bases, Decision-Support Systems (DSS)/Expert Systems (ES), Simulation Models (SM), etc.- to cite a few of the latest developments. Further, cyber space is fast emerging as an area of information technology, particularly in the field of crop pest management (Srivastava and Swain, 1998). The application of information technology in pest management has been one of the most exciting developments in the field over the last decade. From the 1960s, the entomologists began using computers for spray scheduling, population modeling, exploring control strategies and managing pest monitoring data. More recently, computers are being utilized in pest management delivery systems and decision support systems (DSS) designed to enhance decision making.

Introduction

Taxonomy, which includes identification and classification has transformed into systematics and biosystematics in the recent times and is integrating itself into the biodiversity, which is now a global phenomenon occupying the main thrust of human life. The magnitude and cause of this biodiversity is the central problem of taxonomy and one of the key problems of science as a whole, not to speak of pest management. The science of taxonomy started in the late eighteenth century by a Swedish biologist, Carl Linnaeus who with a small number of similar minded scientists pioneered a standard system of using two Latin names for an organism, denoting “genus” and “species” that is still in use. This led to referring of biological organisms by an universally agreed name and identity, and further providing means for their realistic classifications. When these identifications and classifications got strengthened further with accumulated biological knowledge, it allowed the development of modern biology on a sustainable and stable base. In addition, in the recent times taxonomy has become more demanding subject for areas in science and technology, which are dependant on access to accumulated experience and knowledge for their survival and development. Insect pest management is one such area where taxonomy provides the essential scientific basis, without having any claims of its own and integrating itself in such a manner that its role is difficult to delineate precisely.

Introduction

Food security is an agricultural issue that has political connotations in the world and more strikingly so in the developing world, where systems of governance has assumed and lost power on this issue. Agriculture not only contributes to the overall growth of the economy but also provides a vital livelihood base, employment and food security to the majority of the country’s population. Recent food price hikes have drawn the attention of the world’s policy-makers and news media to food security which triggered a wide variety of policy responses throughout the world. It threatens the food crisis and livelihood of millions of peoples suffering from hunger and poverty.

Introduction

Huge population in the developing countries requires increased amounts of food and fiber from a shrinking agricultural land base. Intensification of agriculture through expansion of irrigation facilities, introduction of high yielding varieties and application of increased amounts of agrochemicals has been in progress. Besides, the cultural practices like spacing, crop rotations, sowing times and tillage methods have been modified to achieve maximum productively per unit time from the available land. However, along with various technological achievements, sever outbreaks of insect pests, diseases and weeds in agricultural crops have also occurred. Many hitherto unknown species have assumed serious status and some of the serious pests have developed resistance to one or more groups of pesticides. In addition, pesticides have contaminated different components of our environment and pose a potential health hazard to consumers. Therefore, the future pest problems will have to be tackled in an environmentally benign manner as a part of a sustainable crop production technology (Dhaliwal and Heinrichs, 1998; Koul et al., 2004; Koul, 2008).

Introduction

With the introduction of chemical pesticides in India during 1947 when 250 tonnes of DDT was imported for Malaria eradication programme, there is a steady increase in consumption and at present about 25 per cent of the cropped area is covered by pesticides. Their use has helped in increasing the productivity over the years. The consumption pattern of different groups of insecticides has indicated the same trend. The Indian pesticide industry with 85,000 MT of production in is ranked second in Asia (behind China) and twelfth globally. The Indian pesticides industry is dominated by insecticides where herbicides and fungicides are the key segments globally. Among the pesticides, insecticides account for 57 per cent, fungicide 28.7 per cent and herbicides 14.0 per cent during the year ending 1997-98. Owing to the ban of highly persistent organochlorine pesticides, there is decrease in the trend. Among the different crops, cotton consumes 44.5 per cent of the pesticide worth of Rs.2462.13 millions, even though it occupies only 5 per cent of the cropped area. Cotton is followed by rice (22.00% of pesticides) and other crops.

Introduction

One of the triumphs of modern agriculture is the increase achieved in the productiveness of land, measured by yield of crops per hectare or per acre. This has enabled the earth to support a much greater population than would have been possible in past centuries. The increased productivity of the land is a result of scientific and technological progress in plant breeding, in control of pests and weeds, in irrigation and in fertilizers to supplement natural reserves of plant foods. But this progress makes it more difficult to fulfill one specific requirement of many crops: pollination. Pollination of flowers is an essential step in the sexual reproduction of angiosperms. Most angiosperm species rely on insects or other animals, rather than wind, for transfer of pollen among individual plants. The pollinators in turn benefit by obtaining floral resources such as nectar or pollen. Pollination is not only mutually beneficial to the interacting plants and animals, but also serves humanity directly through the yield of many crops, and indirectly by contributing to the healthy functioning of unmanaged terrestrial ecosystems (Costanza et al.,1997; Nabhan and Buchmann, 1997; Klein et al., 2007; Abrol, 2007 and 2008).

Introduction

The increasingly precarious situation facing the world’s hill regions has been the focus of a growing level of awareness over the past two decades. The high altitude regions offer a challenge to agricultural development agencies which is shared by many hill areas of the world characterized by marginality, extreme diversity, environmental fragility and complex smallholder farming systems. There is justifiable concern relating to the conservation of hill and mountain ecosystems, to the extent that the concept of sustainability has been adopted as a broad slogan by the environmental movement (Lele, 1991).

Conditions specific to mountain regions, such as inaccessibility and diversity have placed a high premium on large families, encouraging population growth. Children are essential to family subsistence strategies offering free labour, and they are consequently considered to be a source of wealth. Population control measures in these regions have ignored this scenario (Sharma and Banskota 1990; Jodha, 1991).

Weeds pose serious problems to agriculture and environment. Weeds are plants that are undesirable to human activity at a particular time and place, and therefore, weeds will always be associated with human endeavours. In agriculture these not only cause huge reductions in crop yields but also increase cost of cultivation, reduce input efficiency, interfere with agricultural operations, impair quality, act as alternate hosts for several insect pests, diseases and nematodes. In non-crop areas, they affect aesthetic look of the ecosystem as well as native biodiversity and health and quality of life. Weeds are a big constraint in crop production and are responsible for heavy yield losses in almost all the crops. “Being fore-warned is fore-armed” is the principle behind preparation of perspective plans. Weeds are big constraints in crop production and are responsible for heavy yield losses in all crops. Out of the losses due to various biotic stresses, weeds are known to account for nearly one third. Proper management of weeds is essential to meet the growing demand of foodgrains, pulses, oilseeds and other crops by the ever increasing population. As per the projections of IFPRI, Washington there is a likelihood of shortfall of 41 per cent in the food grain production in the country by 2020.

Introduction

The main reliance is on the use of insecticides to reduce the losses. The insecticides are the major component of “Integrated Pest Management” (IPM) in almost all the agro-ecosystem. Cotton, paddy, vegetables and fruits are grown in 32% of the cultivated area and account for over 80% of the pesticide consumption in the country. From a modest beginning in 1947, when DDT was first used for malaria control, pesticide consumption in India has grown to a total market size of over Rs. 45000 million in 2003. The total installed capacity of technical grade pesticides is approximately 140,000 tpa. Out of the 204 pesticides registered in the country, 66 technical grade pesticides are manufactured in India.

Introduction

The integrated nature and high diversity of the soil health system may contribute a significant degree of resilience under conditions of disturbance, particularly at lower (largely microbial) trophic levels. Nonetheless, the conversion of natural vegetation to agricultural land results in major changes in both physical organization and community structure in the soil, including species loss and changes in dominance among the surviving biota. This then becomes the resource with which agriculture must work and any targets should realistically be set in relation to the potential equilibria in agricultural systems rather than the natural systems from which they are derived, as has sometimes been advocated. More importantly, it is clear that subsequent agricultural practices may also impair soil health through significant impacts on the composition and structure of the soil biological community and consequently on soil-based ecosystem functions and services. Damage to ecosystem functions can arise both owing to an inadequate supply of resources (carbon, energy, nutrients or water) and through the impact of intensive substitutive practices such as continuous mechanical tillage, the use of pesticides and excessive amounts of fertilizers. These interventions may also impact on soil functions by destroying or changing the habitat of the soil organisms and their capacity to repair it.

Introduction

The concept and impetus for IPM grew out of the discontent with using a purely insecticidal approach to insect control in many areas in the mid of twentieth century. Excessive use of pesticide and growing needs of people has triggered several consequences such as resistance and resurgence of pests, destruction and elimination of natural enemies, effect on non target organisms, environmental pollution, disruption in food cycle and food web and residues in food commodities and pesticide poisoning. Less knowledge about biocontrolagents/natural enemies and their non-availability at right time is the key hurdles for farming communities to adopt the IPM practices on their farm. However, pesticides are still a significant component of many control programs and their negative environmental and health impacts have stimulated the research to develop alternate pest management strategies, such as biological control (BC) and other compatible, safe and sound control practices. Some remarkable early successes for both the control of insect pests and weeds (e.g. the cottony cushion scale Icerya purchase (Maskell) by the vedalia beetle Rodolia cardinalis (Mulsant) in California; the prickly pear cactus Opuntia stricta (Haw.) by the moth Catoblastis cactorum (Berg) in Australia certainly were an impetus for further research in BC field. Although the levels of success have been variable, biological control is still considered as an important means of pest control, either alone or as component of integrated management programs (Jervis, 2005; Wajnberg et al., 2007).

Introduction

Pheromones are chemicals emitted by living organisms to send messages to individuals of the same species. The class most widely explored are the sex pheromones produced by female moths which are used to attract conspecific males for mating. Bombykol, the sex pheromone of the silk moth, was first synthesized in 1959.

During the past 40 years, pheromones of hundreds of insect species have been chemically elucidated, including the sex pheromone of the codling moth. Its main component is (E, E) 8, 10-dodecadien-1-o1, a primary alcohol containing a straight chain of 12 carbons and two conjugated double bonds. Other moth pheromones are hydrocarbons, epoxides, acetates or aldehydes. These molecules all vaguely resemble fatty acids, from which they are indeed biogenetically derived.

Most pheromones consist of blends of two or more chemicals which need to be emitted at exactly the right proportions to be biologically active. The female effluvia or sex gland can contain additional compounds which are related to the pheromone components and whose biological function is often unclear. On the other hand, many attractants of male moths have been discovered simply by field screening. In several cases it could later be shown that the attractant found with this technique was identical to the natural pheromone produced by the female. In most others, the composition of the true pheromone is still unknown.

Introduction

The development of insecticide resistant populations of insect-pests, evidence of resistance, resurgence and environmental concerns have led to increased research for the alternative strategies to pesticides for control of damaging pest populations. Classical biological control and the success in that area are important and provide background and encouragement for increased efforts in the manipulation of natural enemies. Methods for manipulation of natural enemies for the purpose of reducing herbivore populations and alleviating plant stress include conservation and augmentation, habitat management and genetic manipulation.

Virtually all pest populations are affected by natural enemies to some extent. In many cases, natural enemies are the primary regulating force of the pest populations. Natural controls include effects of natural enemies (predators, parasites, pathogens), other biotic (living) factors such as food availability and competition, and abiotic (non-living) factors such as weather and soil. In pest management, biological control usually refers to the action of parasites, predators or pathogens on a pest population which reduces its numbers below a level causing economic injury. Herbivorous insects and pathogens that attack pest weeds are also considered biocontrol agents. Biological control is a part of natural control and can apply to any type of organism, pest or not, and regardless of whether the biocontrol agent occurs naturally, is introduced by humans, or manipulated in any way. Biological control differs from chemical, cultural, and mechanical controls in that it requires maintenance of some level of food supply (e.g., pest) in order for the bio-control agent to survive and flourish. Therefore, biological control alone is not a means by which to obtain pest eradication.

Introduction

Globally, India takes pride of being one of the world’s largest producers of horticultural and agricultural commodities. The rapid increase in the area under intensive cultivation of crops, introduction of high yielding varieties, lack of natural enemy load of the pests and changing climatic conditions is largely responsible for the severe pest depredations. Pest management in agriculture is a challenging task in the context of increasing agricultural productivity without upsetting the ecological balance and deteriorating the environment. Use of agrochemicals in agriculture though played a significant role to boost the agricultural production is posing enormous problems like environmental pollution, pest resistance, pest resurgence, toxicity hazards, secondary pest outbreaks, residues in feeds, foods, soil and water, destruction of biodiversity of useful natural enemies and some social economic and political problems. In response, there has been increased demand for alternative and selective pest control agents. Biopesticides are advantageous due to their target specificity, eco-safety, no development of resistance, reduced number of applications, yield and quality improvement, higher acceptability and value of produce for exports and suitability for rural areas.

Introduction

Indian agriculture accounts for nearly 65% of the country’s employment, 23% of the total GDP and nearly 20% of total export earning and supplier of raw material to major industries. Agriculture is not only the backbone of Indian economy and food security but also a way of life, a tradition and anchor of overall livelihood opportunity for about 700 million of our one billion populations. Agriculture, therefore, is and will continue to be central to all strategies for planned socio-economic development of the country.

Losses due to insect pests represent one of the single largest constraints to crop productivity estimated at 14% of the total agricultural production. Besides, insects also serve as vectors of plant pathogens. The annual global cost of pest management through insecticides is more than US$10 billion per annum. However, over-reliance of insecticides creates agricultural, environmental and pest management problems, such as frequent evolution of insect resistance, destabilization of multitrophic interactions and environmental contamination. Broad spectrum insecticides often compound these problems. Insecticides often interfere with biological control, causing secondary pest outbreaks or catastrophic resurgence of insecticide resistant herbivores. The vicious cycle of pesticide treadmill effect is observed when more pesticides lead to insects developing resistance, which in turn necessitates use of more and newer pesticides. Therefore, now it is imperative to develop a holistic system of tackling pests to make it more eco-friendly, economically viable and socially acceptable for the farmers.

Proteinase inhibitors (PIs) are small proteins that are quite common in nature. They are natural, defense-related proteins often present in seeds and induced in certain plant tissues by herbivory or wounding (Koiwa et al., 1997). PIs are present in multiple forms in numerous tissues of animals and plants as well as in microorganisms. In plants they can be counted among the defensive mechanisms displayed against phytophagous insects and microorganisms. The defensive capacities of plant PIs rely on inhibition of proteases present in insect guts or secreted by microorganisms, causing a reduction in the availability of amino acids necessary for their growth and development. PIs are of common occurrence in the plant kingdom. Plant PIs (PPIs) are generally small proteins that have mainly been described as occurring in storage tissues, such as tubers and seeds, but they have also been found in the aerial parts of plants (De Leo et al., 2002). One of the important defense strategies that are found in plants to combat predators involve PIs which are in particular effective against phytophagous insects and microorganisms. The defensive capabilities of PPIs rely on inhibition of proteases present in insect guts or secreted by microorganisms, causing a reduction in the availability of amino acids necessary for their growth and development (Lawrence and Koundal, 2002).

In the national and International scenario weeds continue to cause major problems in agriculture thereby, reducing yield and quality of crops by competing for the water, nutrients and sunlight essential for vigorous crop growth. Holm et al. (1997) listed about 200 weed species that cause 95% of weed problems for humans. As international travel and global trade increased, more plant species with potentially weedy traits are being moved around the world, giving rise to new, invasive weed problems, particularly in non-agricultural or natural ecosystems (Mack et al., 2000). The importance of weeds is reflected by the rapid growth of the use of chemical herbicides in agriculture throughout the world. The effectiveness of herbicides has dramatically increased yields in many cases and, in turn, stimulated development of new chemical herbicides. However, despite massive efforts, weeds continue to cause significant losses. These losses result from the selection and emergence of species that are not controlled by currently available herbicides, the inability of an herbicide to selectively control certain weedy species without injury to crop species, or the development of resistant strains. Among different management practices plant pathogens have also been suggested as one of several possible means of controlling the weeds that remain problematic or even as an alternative to chemical herbicides. Plant pathogens can be used to control weeds in a similar way to chemical herbicides. The term bio herbicide is coined to refer to herbicides based on any living organism (e.g. fungi, bacteria, viruses, protozoans). When the active ingredient used is a fungus, the product is called a mycoherbicide. Mycoherbicides can be applied in many ways, e.g. as aerial sprays, through ‘cut and paste’ application or in a powder form to be applied to the soil.

Plant viruses are ultramicroscopic particles that multiply only within living cells and are potentially pathogenic while composed of nucleic acids surrounded by protein coat.

More than half of the known viruses cause diseases of plants. All plant species are probably susceptible to one or more plant viruses. Symptoms of virus infection may include stunting, yellowing, necrosis, mosaic, mottling, ring spots, or abnormal structures. Economic damage consists of reduced yield and quality.

Viruses neither divide nor produce any kind of specialized reproductive structures such as spores. Instead, they multiply by inducing host cells to form more viruses. Viruses causes disease not by consuming cells or killing them with toxins, but by utilizing cellular substances during multiplication, taking up spaces in cells, and disrupting cellular processes. These in turn upset the cellular metabolism and lead to the development of abnormal substances and conditions injurious to the functions and life of the cells or the organism. The property of transmissibility is an essential criterion for viruses. Plant viruses are transmitted from plant to plant in a number of ways. Mode of transmission includes vegetative propagation, mechanically through sap, seeds, pollen, dodder and by insects.

Introduction

Horticulture is an intensive but profitable venture with higher output in terms of yield and income per unit area and time. In order to maximize the output, there has been liberal use of inorganic products like fertilizers, pesticides (insectides, fungicides, nematicides, weedicides) and other chemicals. With the continuous application of these chemicals since the last green revolution, the soil and its fertility is showing the sign of fatigue and plants developing resistance to insects, pests and diseases is breaking down and causing overall pollution to soil and water. There is growing evidence of sterility in humans and various other animals, particularly in males, related to the presence of various chemicals and pesticides in the environment. Hence the demand of the hour is looking for some alternative arrangements which are eco-friendly and moreover safe guarding the quality of the produce, which is essential so far as ornamentals are concerned. This is especially true for cut flowers and potted plants. Visible symptoms of insects, pests and diseases, have a major impact on quality. Direct and indirect effects of infections include reduction in growth, reduction in vigor, costs of attempting to maintain crop health, reduction in quality and/or market value (Hadidi et al., 1998). This may cause serious economic losses. In addition, infected plant material may not be acceptable for export.

Fungi include a large group of organisms and there are about 72,000 described species and the total number of species in the world may be as high as 1.5 million (Hawksworth et al., 1995). The infections that these fungi cause on a group of organisms viz. plants, animals, insects etc. may or may not be beneficial depending upon the type of host infected. With reference to insects, fungal infections in pest insects are beneficial which can be used effectively in biocontrol programmes. On the other hand, fungal infections in beneficial insects are harmful.

The entomopathogenic or entomogenous fungi mainly include those genera of fungi that associate with insects and some arthropods in a variety of ways. The association with the insects may be saprophytic, commensalistic, parasitic or pathogenic with the insect host. Some entomopathogenic fungi like Coelomomyces are obligate pathogens which can’t be cultured outside a living host, but most of them are however, facultative pathogens capable of growing without host insect. More than 750 spp of fungi, mostly deuteromyctes and entomophthorales from about 100 genera are pathogenic on insects and many of them offer great potential for pest management. The entomopathogenic fungi which have been most intensively investigated include Beauveria, Metarrhizum, Paecilomyces, Entomophthora, Verticillium, Hirsutella, Eryina, Mefarrhizium etc. Out of them Beauveria and Mefarrhizium have been extensively used in large scale for the control of several crop pests.

Introduction

Worldwide damage due to insect pest attack accounts for 15 per cent crop losses, despite the use of insecticides which represents over US $100 billion (Krattiger, 1997). The annual cost of insect control itself amounts to US $8 billion, thus warranting immediate and economical control measures. The crop varieties developed in the past 30 years were high yielders, but unfortunately had poor storage characteristics and were highly susceptible to pest damage. Insect-pests are capable of evolving to biotypes that can adapt to new situations, for instance they overcome the effect of toxic materials or bypass natural or artificial plant resistance, which further confounds the problem (Roush and McKenzie, 1987). Under these circumstances, provision of food to the rapidly expanding population has always been a challenge facing mankind. This problem is more acute in the tropics and sub-tropics, where the climate provides a highly conducive environment for a wide range of insects and necessitates massive efforts to suppress the population densities of different pests in order to achieve an adequate supply of food. In developing countries, the problem of competition from insect-pests is further complicated with a rapid annual increase in human population (2.5-3.0 percentage) against a meager 1.0 per cent increase in food production. In order to feed the ever expanding population, crop protection plays a vital and integral role in the present day agricultural production to minimize yield losses. Currently, the crop protection practice in agricultural systems relies exclusively on the use of agrochemicals, although a few specific cases do exist, where inherent varietal resistance and biological control have been successfully employed. The exclusive use of chemical pesticides not only results in rapid build-up of resistance to such compounds, but their non-selectivity affects the balance between pests and natural predators, and is generally in favour of pests (Metcalf, 1986).

Introduction

Biotechnology, in the recent years, has created unprecedented opportunities not only for the manipulation of biological systems for the benefit of mankind, but also to understand studies for better understanding of the fundamental life processes. Consequently, it has become the fastest and most rapidly growing technology in the world. As per US National Science Foundation, “Biotechnology is defined as any technique that uses living organisms or parts of organisms to make or modify products, to improve plants, amend animals or to develop microorganisms for specific uses”. Biotechnology offers new strategies that can be used to develop transgenic crop plants with improved growth, yield and quality and tolerance to biotic and abiotic stresses. By transgenic crop, we mean any plant containing a gene(s) which have been artificially inserted instead of the plant acquiring them through pollination. A plant in which a foreign gene has been transferred through genetic engineering is called transgenic plant and the gene so transferred is called transgenic. The inserted gene sequence known as transgene may come from another unrelated plant or from completely different species. Plants containing transgene are often called genetically modified or GM crops. Transgenic technologies have opened up many exciting possibilities to improve products with added value having application in food, agriculture, animal husbandry, environment, medicine and industry. It also offers uncommon opportunities for improvement in genetic potential of plants and animals by introduction or removal of gene(s) that regulate a specific trait.

Introduction

Vegetables are preferable host to many insects because of their succulence and suitable nutritional status. All vegetables are attacked but degree of damage and number of pests varies depending upon the crop, variety and climate. Pest infestation in vegetables has been the main bottleneck in their economical production. The problem has more socio-economic dimensions because of rapid expansion of area under vegetables, intensive cultivation, round the year cultivation, export enhancement and health consciousness among the people.

The diamondback moth (DBM), Plutella xylostella (L.), is a major pest of brassica crops worldwide. DBM has been estimated globally to cost US$ 1 billion in direct losses and control costs. (Grzywacz et al., 2010)

Introduction

Within the very small portion of the plant kingdom that includes the world’s crop plants, the legumes are a large group second to the cereals as sources of human food. Legumes belong to the family leguminosae with a group of bacteria, Rhizobium, which is able to utilize atmospheric nitrogen. This symbiosis which occurs in the root hairs may be the key to the success of legumes worldwide distribution. The family leguminosae includes about 18,000 species, characterized by their fruits, which are pods, by their (usually) alternate, pinnate or trifoliate leaves (Cobley and Steele, 1976). The diversity in the family ranges from hardwood trees of the tropical rain forests to the herbs of temperate pastures.

In practical agriculture, resistance represents the ability of a certain variety to produce larger crop of good quality than an ordinary variety at the same level of insect population. During the 19^th Century, the French wine industry survived a major set-back largely due to the use of resistant root stocks imported from America and which still maintain their resistance levels against the beetle pest (Painter, 1951). Another important example of resistant variety is the U-4 variety of cotton possessing high level of resistance to the jassid, Emposasca spp. (Parnell, 1925). The excessive use of pesticide on oilseed crops needs to be minimized owing to several reasons: (i) most of the pesticides are lipophilic and are likely to be carried in the oil (ii) in a few cases like Brassica, leaves and inflorescence are consumed as saag (pot herb), (iii) the oilseed crops provide the raw material for the vanaspati industry, cosmetics, etc., (iv) many of the oilseeds and oils are directly consumed without further processing, and (v) the oil cakes are used as cattle feed. Thus there is an urgent need to exploit the non-pesticidal methods of pest control, among which the use of resistant varieties assumes a great significance. The details of each oilseed crops are given below:

Introduction

Cereal crops are of global importance and the lifeline of the humane civilization. Nutritionally, they are important sources of dietary protein, carbohydrates, Vitamin B complex, Vitamin E, iron, trace minerals and fiber. Major cereal crops produced worldwide include wheat, rice, maize and millets. Among them, wheat, maize and rice together comprise at least 75% of the world’s grain production. More than 70 per cent of the cereal crop produced in developed countries is fed to livestock whereas, in developing countries, 68-98 per cent of the cereal crop is used for human consumption (Chaven and Kadam, 1989). Rice is the most important and widely cultivated crop in the world and is the staple food for about 60% of the world’s human population. It is basically a crop of humid tropics, but it varies widely in physiological adaptability, hence grown successfully both in tropical and temperate conditions. Wheat (Triticum aestivum L.) is the another important and widely cultivated food crop in the world and important rabi crop of our country. In India, wheat is the second stable food crop after rice which contains more protein than any other cereals. Maize is an important kharif cereal in hilly, sub-mountained and even in plain regions of our country where it forms staple diet of the people.

The global importance of cereal crops to the human diet and moreover to the written history of man and agriculture cannot be overstated. Cereal grains are the fruit of plants belonging to the grass family (Gramineae) most important group of food crops produced in the world. Nutritionally, they are important sources of dietary protein, carbohydrates, complex vitamin B, vitamin E, iron, trace of minerals, and fiber. It has been estimated that global cereal consumption directly provides about 50 per cent of protein and energy necessary for the human diet. Some cereals, notably wheat, contain proteins that form gluten, which is essential for making bread. Major cereal crops produced worldwide include wheat, rice and maize. Wheat, rice, maize, sorghum, and millet are produced in large quantities in India.

Integrated Disease Management

Disease control is, managing the plant disease severity below the economic threshold following economically viable, eco-friendly and easily operational procedures. The position of IDM in the overall agricultural system indicates clearly that it is an important sub-system and interacts with other such systems that fall under the cropping system.

Introduction

Vegetables contain large quantities of minerals, vitamins and essentials amino acids required for normal functioning of human metabolic processes and plays an important role in food and nutritional security. India is the second largest vegetables producing countries next to China and occupies 7.981 million ha area with an annual production of 129.077 million tons (Anonymous, 2009). Due to expanding urbanization and deforestation, most of the natural resources are depleting and shrinking with a rapid pace. With the limited land and depleting water resources, India has to feed the burgeoning population without destroying the ecological balances. In this context, we must have to look after the vertical expansion through increase in the intensity, diversification, mixed and intercropping of vegetable crops. Besides this, vegetables are also more prone to insect pests and diseases mainly due to their tenderness and softness as compared to other crops.

Vegetables not only provide nutritional security but also income security to small and marginal land holders growing vegetables in the hinterlands of urban markets and dollar earners in global markets. India is endowed with favorable tropical, subtropical and temperate climate making it conducive for producing high quality vegetables round the year in one or other part of the county. As far as production is concerned, India is in number two in the world after China. But, as a matter of fact, in terms of productivity and subsequently for per capita availability, we are still lagging behind many countries of the world. Per capita availability of vegetables is 210-gm/capita/day against 300 gm/capita/day recommended by ICMR. There is urgent need to increase the productivity of vegetables in our country to feed the increasing population.

Introduction

Mites and ticks belong to acarology an offshoot of animal science Zoology a common man mites and insects look alike but former can be easily differentiated by absence wings and antennae and presence of four pairs of legs in most farms. Parasitic mites and ticks live on domestic animals, pets and poultry (Baker and Pritchard, 1960; Baker and Tuttle, 1994; Krantz and Walter, 2009). They are responsible for inducing paralysis, host intoxication, irritation carriers of pathogens and other health disorders to them. The severe bites of ticks cause tick toxicosis producing deep wounds, which bleed and are open to secondary infection. Parasitic mites are among the serious pests of the bees the world over. At times they cause mass mortality of brood and put a heavy loss to apiculture industry. Both solitary and social bees that are important pollinators are parasitized by Messostigmatid mites reducing their life span and foraging efficiency. They parasitize silkworm larvae, pupae and adults. By their toxication silkworms die in few hours. Man himself is not free from the attack of mites. Human itch mite, scabies mite and pyroglyphid mites causing allergic asthma are notorious examples of parasitic mites on man. Dancing on the head of a pin’ is definitely impossible for most animals. However, a large number of mites, the smallest Arachnida could do it. The size of these creatures ranges from a fraction of a millimetre, invisible to the naked eye, to about one centimetre in ticks.

Introduction

India is bestowed with a wide variety of agro-climatic conditions and has unique comparative advantage for growing almost all horticultural crops (fruits and vegetables) in the country. Horticulture has remained as a major sub-sector of agriculture and forms an integral part of food and nutritional security, employment generation and enhancing the farm income. The growing economic importance of these crops could be attributed to increasing demands in domestic as well as in overseas market. The total area under fruit is 6.10 million hectare and total production is 68.47 million tonnes which accounts for 11 per cent of the world total fruit production (Anonymous, 2009).

Since, there is a limited scope to enhance the horticultural production in traditionally growing areas, emphasis has to be laid on harnessing the potential of vast wasteland and dry land spread over more than half of the geographical area of the country. Dry and rainfed area constitutes a major share of wasteland and untapped land resource where several indigenous horticultural crop species can be commercially exploited to strengthen the agro-based industries and providing the livelihood to the masses.

India is the second largest producer of fruits and vegetables. The area under fruits alone is 32.05 lakh hectares with a production of 329.55 lakh tones. Jammu and Kashmir is the most important horticultural state with unique temperate fruit and European type of vegetable crop production. The total area during 2005-06 under the fruit crops in the state was 2.83 lakh hectares with a production of 1504.01 thousand metric tones (Table 1). Almost 45 per cent of economic returns under agriculture sector are contributed by horticulture, thereby adding 7 per cent to the Gross State Domestic Product (Anonymous, 2007). Among the fresh and dry fruits, apple and walnut, respectively, are the most important fruit crops in the Jammu and Kashmir. However, there is a wide gap between the present yield and the potential yield of fruits. One of the limiting factors for this gap in fruit production is severe attack of arthropod pests and diseases affecting yield and quality. Unlike agricultural crops, horticultural crops are grown as perennial monocultures, therefore, harbor the insect pest and disease problems that are entirely different and complex in nature. These two factors impose huge losses upon horticulture in terms of alleviated production, reduced quality and cost of management.

Introduction

Fruits, oldest forms of food known to man, are not only good source of nutrition to the body but also have medicinal property and treat ailments. Fruits like apple, lemon, orange and pomegranate aid in proper functioning of the heart. Nutrients in apple, date and mangoes sharpens memory, prevents exhaustion, hysteria, insomnia and mental tension. All berries are rich in iron, phosphorus and sodium which are essential minerals for blood building and nervous system strengthening. Liver ailments, indigestion and rheumatism can be cured by the use of Lemons. Watermelons are good kidney cleansers. Pineapple, pomegranates help in soothing inflammation of nose, throat, fever and other chronic or bronchial ailments. Grapefruit juice is an effective aid for common cold. Fresh and ripe fruits like grapes, apples, bananas and figs are good for all brain deficiencies. Even the kernel of walnut is a helpful remedy for weakness of the brain.

Introduction

Plant parasitic nematodes occur wherever plants grow. These nematodes are referred to as plant pathogenic when they cause crop losses by direct injury to roots, stems, leaves and seeds. A large number of plant parasitic nematodes have been found associated with fruit crops in all over India but pathogenisity has not been proved for all. Most of commonly occurring nematodes belong to genera Meloidogyne spp., Pratylenchus spp., Rotylenchulus spp., Hoplolaimus spp., Tylenchulus spp., Xiphinema spp., and Radopholus spp. etc. The nematodes damage the crops not only by feeding on plants but also by interacting with various other organisms like fungi, bacteria and viruses etc. Estimated overall average annual yield loss of the world’s major crops due to damage by plant parasitic nematodes was 12.3%. Estimated annual crop losses in India have been accounted to Rs. 242.1 billion. The crop losses due to nematode pests are not only in the form of reduced plant growth and yield but are also in the marketable quality of the produce.

Introduction

Walnut is the oldest cultivated fruit in the world (Ozkan and Koyuncu, 2005). Juglans regia L., the Persian walnut, is probably native to a wide region extending from the Carpathian Mountains across Turkey, Iraq, Iran, Afghanisan and southern Russia to northern India. Species of walnuts, genus Juglans, are found in the forests of the eastern and southern parts of the USA, in Mexico and Central America, the Andean parts of Southern America from Columbia to Argentina, the West Indies, Japan, China, southern Asia from India to Turkey and southern Europe to the Carpathian Mountains of Poland (McGranahan and Leslie,1990). The trees are large and tall with round headed canopy. The rather smooth, light coloured, large nuts are free of the hull at maturity. Shell thickness varies from paper–thin to very thick and hard. The Greeks probably obtained J. regia from Persia from where, the seeds were transported to Rome, where they were known as Jovis Glans, or Jupiter’s acorn, from which comes Juglans. From Italy, it spreaded to what is now France, Spain, Portugal and southern Germany. Trees of the species were in England by 1562, and were bought to America by the earlier settelers. The American colonists are said to have called the species English walnut to distinguish it from the eastern black walnut, J. nigra. It is generally prefer to call it Persian walnut as it is associated with the place of origin bit commercially, it is called as English walnut. The term Carpathian walnut is sometimes used to refer to cold hardy Persian walnuts (Forde and McGranahan,1996). The other important species are J. ailantifolia Carr. syn. J. sieboldiana Maxim. (Japanese walnut), J. nigra L. (American black walnut), J. cinerea L. (butternut), J. microcarpa Berlander (Texus Black walnut), J. major Heller (Arizona black walnut), J. californica S. Wats (Southern California black walnut) and J. hindsii Jeps. (Northern California black walnut).

Introduction

The cultivated strawberry (Fragaria x ananassa Duch.), octoploid in nature is a result of hybridization of two American species, the Chilean F. chiloensis and Virginian F. virginiana. The name strawberry does not incidentally, seems to have anything to do with the practice of putting straw around the plants and long predates their cultivation. It probably comes from ‘strayberry’ for the runners cause young plants to stray from the parent. Strawberry (Fragaria x ananassa Duch.) is one of the most important soft fruits, and its cultivated area has increased significantly during the last few years in sub-tropical areas despite of its temperate nature. Being a high input requiring crop, the profit of margin is reduced in sub-tropical areas due to lack of runnering caused by high temperature and high light intensity. Strawberry is one of the most popular rosaceous vegetable used as preferable fruit has a great value for local consumption as well as for export. Attractive appearance, unique taste, availability of fresh fruits during the period of fresh fruits scarcity in the market, short duration nature, high return per unit area, twice earnings in a year (through fruits during spring and runners during autumn) and wider acceptability of its processed products, the strawberry has become a choicest crop of growers of sub tropical areas, and being grown commercially around the various cities of northern India. Although it is a quick and high return giving fruit crop, but the margin of profit in strawberry cultivation under sub-tropical areas is greatly reduced due to regular annual investment (Rs. 0.60 lakhs/ha) by the growers for the procurement of runner plants in every planting season (October) from temperate areas, as high temperature (>35⁰C) and intense light following fruit harvesting restrict the runnering as well as survival of mother plants in these areas (Sharma and Yamdagni, 2000).