eChapters

INTRODUCTION

Now-a-days, food products with maximum health benefits and ease in preparation are gaining popularity globally, the reason being changing awareness level about food and dietary habits. Since ages, a number of methods like cooking, baking, drying etc. have been used to thermally process the food materials. Electrical sources of electromagnetic waves are very promising because of advances in nuclear and hydroelectric power as well as ongoing cost rises in traditional forms of fuel, of which there are only restricted reserves. The heating aids include use of wooden fuel, gaseous fuel, electric energy etc.; but the new era of electromagnetic rays had introduced new horizons of food processing by utilizing it in various unit operations (Sakai and Hanzawa 1994). Though, these radiations are gaining popularity in various walks of life; their destructive impact is much dominating. Hence, one should handle these radiations with utmost care as well as comprehensive understanding of the know-how and control over the process.

INTRODUCTION

Radiation processing is a promising technology for improving hygiene and increasing storage and distribution life of food products. Ionizing radiation can be used to bring about beneficial changes in food stuffs (Urbain 1995) and it has been suggested as a method of ensuring safety of meat products (Patterson and Stevenson 1995). Ionizing radiation interacts with an irradiated material by transferring energy to electrons and ionizing molecules by creating positive and negativities (Moseley 1989).

INTRODUCTION

Preservation of food by drying or chemical means as by alcohol or acid fermentation and that by the use of ice is long recorded in history. With the advancement of science and the knowledge governing various unit operations in food processing, these food preservation techniques employing thermal, radiation, or low temperature or a combination of these have only got further refined as regards their viability and commercial applications. Process foods of different genre and cuisine, which include frozen foods too, are increasingly becoming popular the world over for reasons of quality, safety and year round supply of nutritious foods to cater to different niche segments of human society. Increasing health consciousness is buoying those processed foods which are preserved and stabilized using non-thermal technologies as these ensure retention of food nutrients to a better definition. Interest in frozen food also stems from need to deliver safe and nutritious foods with extended shelf-lives.

INTRODUCTION

Drying or dehydration is defined as the removal of moisture from its initial level to a level which renders food materials safe for subsequent storage. It is a simultaneous heat and mass transfer operation in which heat is supplied externally to evaporate moisture and air is forced through the bed to carry away the moisture. Drying is the oldest technique to preserve food materials. Advantages of drying include reduction in water activity, enhancement of shelf life, maintenance of flavor and nutritive value, and reduction in packaging and transportation costs. When the water activity of the dried product is reduced to below 0.6, most microorganisms do not grow and the rates of other deteriorative reactions are substantially reduced.

INTRODUCTION

A mixture is a combination of two or more elements or compounds in any proportion so that the components do not lose their identity. Most materials in our world are mixtures and very few materials are pure substances. Foods are complex mixtures of compounds and the extraction or separation of food components is fundamental for the preparation of ingredients to be used in other processes. Separations usually aim to remove specific components in order to increase the added value of the products, which may be the extracted component, the residue or both. Purposes include cleaning, sorting and grading operations, extraction and purification of fractions such as sugar solutions or vegetable oils, recovery of valuable components such as enzymes or flavour compounds, or removal of undesirable components such as microorganisms, agricultural residues or radionuclides. For example, cooking oils from oilseeds or gelatin from connective tissue; or for retrieval of high value compounds, such as enzymes (e.g. papain from papaya for meat tenderisation or rennet from calf stomachs for cheese making). Other types of separation methods are used to sort foods by separating them into classes based on size, colour or shape and to clean them by separating contaminating materials.

INTRODUCTION

Food is the basic need of human beings. It gets spoiled primarily due to microorganisms and enzymes. Energy is required for microbial growth and enzymatic reactions. At low temperature, the rate of biochemical reactions is slow resulting in prolonged storage life of food. It must have been observed long back that food could be stored for longer period without deterioration during the winter months. Since then this principle is being used to extend the storage life of foods. A sea change can be observed in development of low temperature preservation technology. It has travelled a long journey to reach this stage; however, a major break through took place in twentieth century. Low temperature technology is of two types; refrigeration and freezing. In refrigeration storage, water is in liquid phase and temperature is maintained above freezing point. In freezing technology, the food is stored below freezing point and water gets converted into ice. The former is short term preservation due to slow growth of microbes and lower enzymatic activity while the later is long time preservation due to inactivation of enzymes during blanching and inhibition of microbial activity due to unavailability of free water and much lower temperature. Low temperature preservation is widely accepted and is of commercially important in food supply chain.

INTRODUCTION

The concept of hurdle technology has been developed as a new way to realize safe, stable, nutritious and economical foods. It employs combination of different preservation techniques to achieve a multi-target, mild but reliable preservation of foods. The application of hurdle technology in food preservation is increasing rapidly worldwide. Over the years, insight into the hurdle effect has been broadened and the application of hurdle technology has been extended. A better understanding of the occurrence and interaction of food preservative factors (hurdles) in foods is the basis for improvements in food preservation. If the hurdles for the microbes are known, the microbiological stability and safety of this food might be optimized by changing the intensity or quality of these hurdles. Using the proper combination of hurdles, it is possible to improve not only the microbial stability and safety but also the sensory and nutritive quality as well as the economical aspects of food. The hurdle concept is also referred to as food preservation by combined methods, combined process, combination preservation or combination processing techniques. The hurdle effect is of fundamental importance for the preservation of foods. The illustration of hurdle effect was first introduced by Leistner in 1978. Based on the understanding of hurdle effects, the concept of hurdle technology was derived (Leistner 1985).

INTRODUCTION

By the turn of the century, consumers have been more demanding, sophisticated and discretionary. They want much safer, higher quality, and more convenient to foods. The food processor need to get the best from their existing processing technology in addition to looking for newer ones. New and alternative food processing methods and/or novel combinations of existing methods are continually being investigated by the industry in pursuit of producing better quality foods more economically. Thermal processing is one of the most important food preservation techniques that was first introduced at the beginning of 1800 and has evolved itself in to one of the most scientific mature food processing techniques of recent times. Both science and technology have gone through tremendous transformation in the last two centuries and today it is the most reliable method to assure food safety and stability. Developments in thermal processing and evolution of non-thermal processing technologies like high pressure processing, pulsed electric field, pulsed light etc. have enhanced the utility of thermal processing principles and increased the awareness of possible alternative processing technologies.

INTRODUCTION

Food processing is necessary for the conversion of raw food products in to finished products with desired textural, sensory and nutritional attributes. This is required to be done mainly due to seasonal production and facilitating non-seasonal availability of different commodities. Stages of processing are primary and secondary. In primary processing raw material is converted into food commodities, while in secondary processing commodities are converted into edible products. Processing is mainly done to convert the products into edible forms, to extend shelf life, availability, accessibility and also to provide variety into the form of value added products. Processing of products destroys inhibitors, microorganisms, retards physico-chemical and biochemical deterioration, maintains good sensory properties, preserves and enhances the nutritive value. Unit operations involve phase changes and sometimes chemical reactions also, which are undesirable as they cause inferior quality of the product (Gekas 1992). Different processes like separation, assembly, preservation and packaging are broader classification for unit operations in food processing (Saravacos and Kostaropoulos 2002).

Food Science is one of the ancient sciences and the genesis originates to the very beginning of human civilization. The advent of food science was associated with practice and observation by humans before establishment of scientific concepts. The ancient man knew that roasting or smoking of meat improves the edible quality and digestibility. As a consequence, he started practicing the same much before the reasons for the same could be established. Many of the modern preservation concepts had their origin in prehistoric period itself as humans could use techniques such as dehydration, fermentation and pickling to their advantage to improve the sensory attributes of the products and also to enhance their shelf life. Humans during the Pre-Neolithic period about 2,50,000 years before used fire for cooking meat. During the Paleolithic period humans not only roasted food but also developed grinding, pounding and drying. During the Mesolithic era, humans were desperate for food and got involved in extensive hunting and fishing. During the same time domestication of animals took place and animal husbandry became a reality (Stewart and Amerine 1982). The Neolithic period made qualitative changes in the food habits of humans and they changed from a food gathering and hunting society to one of food production (Heizer and Elsasser 1980).

26.1 Introduction

The green revolution brought dramatic changes in productivity of rice and wheat and the production increased tremendously using high yielding wheat and rice varieties coupled with fertilizers and pesticide use to meet urgent demands of food. The world population is growing rapidly at an alarming rate. It has crossed 7 billion mark and is expected to become between 8.3 and 10.9 billion by 2050 (United States Census Bureau (USCB). India is second largest populous country of the world with 17.4 % of world population. Such an enormous overpopulation will result in extreme pressure on environment, global food supplies and energy resources. The less arable land and fewer renewable and non-renewable resources, the food production has to come from increases in production rather than expansion of cultivable areas.

Like other sciences, the insect–pest management research is also based on scientific methods requires formulation of hypothesis from observed facts through logical arguments which in turn, verified through objective methods. For instance, in integrated pest management the entomologists are primarily concerned with the estimation of insect-pest population, its distribution pattern over time and space, its relationship and fluctuation in population with the effect of weather parameters and ultimately its control measure through the judicious use of chemicals, biological control agents and resistant varieties etc. Two major practical aspects of scientific investigation are as 
    ·    collection of data and 
    ·    interpretation of the collected data.

24.1 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 (Narendran, 2001). 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” which is still in vogue. 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.

23.1 Introduction

Cultural methods have been in practice for pest management in traditional systems of agriculture since time immemorial. The worldwide awareness of safe environment provided the impetus to foster non-chemical pest management strategies. Of these strategies, cultural control constitutes the most farmer-oriented approach, where the weak points in the biology and behaviour of insects are exploited and pressure is exerted on the population by manipulating the environment.  In addition to the cultural practices, the other widely used approach is the use of physical control methods which hold promise and provide an attractive alternative to current practices, particularly when integrated into a general control scheme incorporating cultural methods, plant breeding, biological or behavioural methods and pesticides. In physical control methods, the physical environment of the pest is modified in such a way that the insects no longer pose a threat to the agricultural crop.

22.1  Introduction

Plant pests have been part of man’s environment for a long time. Traditional agriculture, which included diverse crops and indigenous crop management practices, provided little opportunity for 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 poor farmers. However, in the quest to increase 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.

21.1 Introduction

Plants and insects share a wonderful relationship. Both are dependent on each other at different levels and chemicals emitted by plants connect them to a large extent.  “Plants” contribute to a major share of occupancy on earth and makes several organisms such as insects & microbes and also humans to depend on them for their survival. This dependency leading to several interesting interactions between plants & insects which are often utilized by humans for their own benefit. Plants maintain incredible communication with their associated organisms. Since plants are rich banks of chemicals and constantly emit them in to its immediate environment which contributes in communication between insects and plants. Insects are the major organisms that have a long relation with the plants and there are several incredible ways how plants can interact with insect species.

Chemical ecology is the study of ecological interactions between organisms mediated by chemical produced by those organisms. In short it is considered as the ecological functions of the chemicals. An insect, in various stages of its life history, performs various activities like host plant location, host plant selection,  feeding and oviposition, mating, escape from its natural enemies etc. and the chemicals play a crucial role than visual and audio signals. Chemical ecology encompasses the studies of these chemicals based interactions.

19.1. Introduction

A wave of research on insect pheromones has been initiated in early 1960’s in response to public concern and alarm about chemical pesticides to develop an elegant and ecologically safe technology for the control of insect pests. Pheromones, a class of semiochemicals are considered as ‘Biochemical Pesticides’, belong to the subdivision of Biorational pesticides which include “Microbials” (Viruses, Bacteria, Pathogens etc.) and “Biochemicals” (insect plant growth regulators, semiochemicals etc.). The term biorational (biological + rational) pesticides can be defined as the use of specific and selective chemicals, often with a unique modes of action, that are compatible with natural enemies and the environment, with minimal effect on non-target organisms. Biorational control is based on a diversity of chemical, biological and physical approaches for controlling insect pests which results in minimum risk to man and the environment (Horowitz  et al., 2009).

Plantation crops are high-value commercial crops of greater economic importance which play a pivotal role in the world economy. These include coconut, arecanut, tea, coffee, rubber, cocoa, oil palm, cashew. In this chapter only Cashew and Rubber are dealt with since the other plantation crops have been dealt in the earlier chapters.

17.1 Introduction

Cotton is a major fibre crop of global importance and has high commercial value. It is grown commercially in the temperate and tropical regions of more than 100 countries. Specific areas of production include countries such as China, USA, India, Pakistan, Uzbekistan, Turkey, Australia, Greece, Brazil, Egypt etc., where climatic conditions suit the natural growth requirements of cotton. These include periods of hot and dry weather and adequate moisture obtained through irrigation. Cotton crop is considered as one of the most important cash crops that influenced the industrial and agricultural economy of the different cotton growing countries of world. Thus, cotton is an immensely important crop for the sustainable economy of these countries and livelihood of the farming community. Cotton crop is considered as one of the most important cash crops that influenced the industrial and agricultural economy of the different cotton growing countries of world. Cotton cultivation and textile industry provide livelihood to million persons, therefore any failure of cotton crop significantly influence the economic growth of cotton belt and textile sector.

16.1 Introduction
According to Howard (2001) the major world crop palms are coconut palm (Cocos nucifera L), African oil palm (Elaeis guineensis Jacq.) and date palms (Phoenix dactylifera L). Many other palm species provide products for international commerce and also grown as ornamentals. Some palm species are of local or regional importance and have great potential for expanded development and distribution. In general, commercial production of palms regularly starts on or near natural habitats with little agricultural development.

15.1 Introduction

In recent years, the role of plant secondary metabolites as protective constituents in the human diet has been a growing area of research. Unlike the traditional vitamins, they are not essential for short-term wellbeing, but there is increasing evidence that modest long-term intakes can have favourable impacts on the human health. Teas, coffee and cocoa represent plantation cash crops grown in many of the warmer, less developed regions of the world. They serve as stimulant beverages and their demand is ever increasing day by daily. However, production of these beverages is under the severe threat due to attack from various pests and diseases which cause considerable damage.

14.1 Introduction

Sugarcane, basically a tropical crop in nature, requires a suitable high temperature, a lot of sunshine and rainfall ranging from 1250-2500 mm for its growth and yield. Relatively speaking, it is an intensive user of water as compared to rice and other crops. The total water requirement to mature the crop is about 64-80 acre inches.  Although globally but Brazil and Mexicos in Americas, India, Pakistan, Thailand and China in Asias, Australia and Africa, the Caribbean and to a smaller degree in southern Europe and the Middle East are major sugarcane growing areas in the World (Khan and Jamil, 1983). Historically famous for sugar, this crop has now attained a significant nadir for biofuel production (Mino, 2010).

Sugarcane, a perennial grass, is exposed to all sorts of biotic and abiotic adversaries. The variation in weather parameters like sunlight, temperature, rainfall, humidity and solar radiation affect the different phases of growth like germination, tillering, cane formation and cane stalk elongation, as well as the maturity and ripening phases of plant (Malik, 2009).

13.1 Introduction

Citrus is one of the important fruit crops in India with the production of 111.47 lakh tons from 10.78 lakh hectares with the productivity of 10.34 tons/ha at national level as compared to 25-30 tons/ha in advanced citrus producing countries (NHB, 2013). The productivity and quality of citrus is severely affected by several factors; insect pests being one of them. More than 250 insect pests were reported to attack citrus in India. A total of  22 insect species  in Punjab (Atwal, 1976) ; 50  insect species  in  Karnataka;  42 insect species  in  North-Eastern Hilly region (Pathak and Rao, 1999);  20 insect species in West Bengal and  about a dozen  insect species  in central India have been reported on different citrus cultivars. Further, the pest occurrence and distribution in India indicated that about 21 species are common throughout the citrus growing areas and remaining species may occur in some areas either occasionally or rarely. Of the reported insect pests, Asian citrus psyllid (Diaphorina citri Kuwayama), citrus blackfly (Aleurocanthus woglumi Ashby), whitefly (Aleurolobus marlatti (Quaintance) and Dialeurodes sp.), leaf-miner (Phyllocnistis citrella Stainton), lemon butterfly (Papilio demoleus Linn.), leaf folder (Psorosticha zizyphi Stainton), aphids (Aphis spp. and Toxoptera spp.), thrips (Scirtothrips spp.), mealy bugs (Planococcus citri Risso), scales (Coccus hesperidus Linn), fruit sucking moth (Eudocima spp.), fruitfly (Bactrocera sp.), citrus trunk borer (Anoplophora versteegi Ritsema), bark eating caterpillar, lndarbela spp.

Introduction

Banana (Musa sp; family: Musaceae) is the most popular commercial soft fruit crop grown in equatorial and subtropical regions of the world and also serves as a staple food since the dawn of recorded history in many countries (FAO, 2012). It has bounties of significance to the human beings and is one of the 4th most important food in the world after rice, wheat, and maize. Musa species grow in a wide range of environments ranging from the edible bananas and plantains of the tropics to cold hardy fiber and ornamental plants. They thrive well in an average annual temperature of 20^°C and well distributed rainfall of 200 cm per year (Simmonds, 1959; Wardlaw, 1961). Banana is a large, perennial, monocotyledonous herb 2-9 m in height that arises from large, subterranean rhizomes called ‘corms’. Musa fruits are variable in size, shape, and color. They are generally elongate cylindrical, straight to strongly curved, 7-40 cm long, and 2-8 cm in diameter. The fruit apex is an important attributes in variety identification.

11.1 Introduction

Tropical Root and Tuber Crops serve as primary or secondary staple to meet the calorie needs of one fifth of world’s population. These crops have myriad and complex roles to play in the food security and reduction of hunger and elimination of poverty. The starch content, pharmaceutical and nutraceutical value endow these crops with an extra ordinary range of potential and uses. Root and tuber crops are also greater sources of industrial raw materials for biodiesel and starch derived materials.

10.1 Introduction

Grain legumes such as chickpea, pigeonpea, cowpea, field pea , lentil, ,  and Phaseolus beans are the principal source of dietary protein among vegetarians, and are an integral part of daily diet in several forms worldwide. They are an important component of cropping systems to maintain soil fertility because of their ability to fix atmospheric nitrogen, extract water and nutrients from the deeper layers of the soil as compared to cereals, and add organic matter into the soil through leaf drop. However, grain legumes are mainly grown under rainfed conditions and the productivity levels are quite low mainly because of severe losses due to insect pests and diseases.  Average grain yield of pulses (0.86 t/ha) is only about one-fourth the average yields of cereals (3.54 t/ha).  Production and productivity of grain legumes is constrained by several biotic and abiotic factors, and suffer an average of 31.9 to 69.6% loss in crop productivity due to insects, diseases, drought, weeds,  and soil fertility. Pod borers (Helicoverpa and Maruca), Fusarium wilts, viral diseases, Ascochyta blight and Botrytis gray mold (Chen et al., 2011).

9.1 Introduction

Cereal crops are of global importance and the lifeline of the human civilization. The four most important cereals grown for human food in the tropics are rice, maize, sorghum and pearl millet. There are other minor cereals of tropical origin which are of local importance in the tropics. These include finger millet (Eleusine coracana), a staple food in parts of East and Central Africa; barnyard millet (Echinochloa frumentacea), cultivated in India and Southeast Asia; foxtail millet (Setaria italica), grown in parts of India; and teff (Eragrostis tef), which is confined to the Ethiopian highlands. The winter cereals wheat and barley are also grown to a limited extent in the tropics, largely at high altitudes: for example, wheat in Kenya and barley in Ethiopia. Wheat and barley are important crops in the Indian subcontinent, and are grown there in the cool season at low altitudes, but the bulk of the crop area lies outside the tropics.

8.1 Introduction

Vegetables are cultivated over an area of about 19 million ha globally, with an annual production of 268 million tonnes; Asia and Africa account for more than 90% of the hectarage and production (FAO, 2011). Vegetable crops contribute to human and environmental health. Most vegetables can supply plant proteins, vitamins (especially vitamins A and C), folic acid, minerals such as iron and calcium, and dietary fiber to the human diet (Fowler, 2011). Vegetable legumes also fix atmospheric nitrogen in the soil, thus improving soil fertility. Their haulms can be used as high quality livestock fodder. Most vegetables are high-value, repeat-cycle crops that can help lift small-scale farmers out of poverty in developing tropical countries (Genova et al., 2010). However, vegetable production is often constrained by several severe biotic- and abiotic factors that reduce yields and profits.

7.1 Introduction

Sustainable agricultural systems must be adopted to increase the food production keeping in view of increase in human population. In tropical countries, insect pests are major challenges to increase food production by causing significant damage in the crop fields and stored grains and their products. Interventions by implementing timely integrated pest management strategies are necessary to reduce the yield losses. Efforts to control insect pests have predominantly relied on the use of broad-spectrum insecticides.  However, indiscriminate and irrational applications of insecticides have created the problems such as insecticide resistance, resurgence, secondary pest outbreak and the presence of residues in food and environment (Ansari et al., 2013). Globally, to reduce the pesticide dependence, various technologies have been developed using different approaches to monitor and maage insect pests which are discussed in this chapter.

6.1 Introduction

The sensitivities of plants and of crop yield to a changing climate, is a major challenge for the agricultural research community to relate these findings to the broader societal concern with food security. This chapter reviews the direct effects of climate on both crop growth and yield and on plant pests and pathogens and the interactions that may occur between crops, pests, and pathogens under changed climate. The better understanding of the roles of pests and pathogens in crop production systems that might   make to enhanced food security is discussed. Evidence for the measured climate change on crops and their associated pests and pathogens is starting to be documented. Globally atmospheric CO₂ has increased, and in northern latitudes mean temperature at many locations has increased by about 1.0–1.4 ^°C with accompanying changes in pest and pathogen incidence and to farming practices. Many pests and pathogens exhibit considerable capacity for generating, recombining, and selecting fit combinations of variants in key pathogenicity, fitness, and aggressiveness traits that there is little doubt that any new opportunities resulting from climate change will be exploited by them.

5.1 Introduction

Rainfed agriculture accounts for about 60-95% of farmed land in major areas of the world covering Saharan Africa, Latin America, North Africa and East Asia and South Asia. Agriculture in about 60 percent of 142 m ha of net cultivated area in India is rainfed without access to any source of irrigation. Rainfed agriculture is mostly practiced in arid, semi-arid and sub-humid regions where the rainfall is low in quantity, erratic in distribution and is also characterized by high inter-year variability. Together with poor and degraded soils, this limits the length of growing season as well as the choice of crops that can be grown sustainably. Coarse cereals, pulses, oilseeds and cotton dominate the cropping pattern in the regions where rainfed agriculture is concentrated. More importantly, these rainfed regions provide a livelihood to a majority of the rural poor, and as a result they are often described as concentrations of mass poverty and hotspots for civic strife. The productivity of crops grown in rainfed areas is considerably lower than its potential and much lower than that of irrigated crops. Enhancing the productivity of rainfed crops is therefore important from the viewpoints of growth, equity and sustainability.

4.1 Introduction

Insecticides, biocontrol agents and resistant varieties are the three important pest management tactics in vogue across the globe. Though several biocontrol agents have been recorded on major pests of economically important crops, mass multiplication techniques for most of them are yet to be perfected, and in several instances, the inundative releases of natural enemies are costlier than chemical insecticides. Moreover, unlike perennial crop ecosystems, the annual crop ecosystems like rice, cotton, sugarcane, pulses, etc. are frequently disturbed and hence, inoculative releases of biocontrol agents are often impractical. Above all, in spite of sustained effort from dedicated plant breeders across the globe, the resistant varieties with outstanding yield potential are very limited in numbers. Genetic engineering of crop plants though paved the way for introducing insecticidal genes more precisely and efficiently, the poorly understood ecological and sociological implications of genetically engineered crops in their target environment resist their strong footing in the pest management programmes in most of the crops especially of food crops. In this backdrop, insecticidal interference is inevitable to manage the insect pests, and they are the only weapon whenever the pest population crosses the economic threshold level.

Introduction

The tropics extends on  vast region of the earth surface ranging from 23½^°C North to the Tropic of Cancer and 23½^°C South to the Tropic of Capricorn. Several countries of Asia, Africa and Latin America include tropical areas. The tropical regions are the warmest area on the earth with average temperatures ranging between 20^°C and 35^°C. More than 80 % of the area in tropics supports forests and savannah and only 15% is under deserts, shrubs and grasses. About 5% of the area is under mid or high altitude with moderate climatic conditions. Evidently, the tropics support great diversity of physical and climatic conditions in different ecologies and different ecosystems. Temperature and daylight length is much higher throughout the year which induces more number of insect pests, their generations causing more damage in tropics. The increased menace of insect pests requires frequent and repeated use of chemical pesticide to mitigate the insect pest damage.

2.1    Introduction

The hot and usually wet conditions in tropics adversely affect the performance of insecticides as well as biology of the pests. Pesticide usuage is declining throughout the world, but in tropics it is likely to increase threatening basic biological components of pest management, environment and safety of people.  Pest management in tropical agriculture is basically influenced by high diversity of organisms, diversity of physical features and ecosystems, moderate seasonal weather changes, and the human factor. The high biological diversity of the tropics includes a wide range of interacting organisms from which have been identified pests that affect health crops and livestock as well as cultural practices for pest management.  Physical features of the tropics are also diverse, and include high-altitude temperate zones, rain forests, savannah woodlands, grasslands, and desert zones. Each zone has its own biological diversity either existing in isolation or overlapping with others. Moderate seasonal weather changes in the tropics affect populations indirectly, through modification of interactions between organisms.

1.1 Introduction

The human population is growing rapidly at an alarming rate, disproportionately to the production of food supplies, which will necessitate production of more food in the near future. The human population has already crossed the 7 billion mark and is expected to rise over 8-10 billion by 21st century. More than 800 million people are reported to suffer from malnutrition (Matson et al., 1997).  Thereby necessitating the need for more food production. Presently, agriculture faces the double challenge of feeding a fast growing population and at the same time prevents the degradation of the agricultural resource base. There appear to be two options for developing countries; either to improve agriculture through modernization, by emphasizing pesticides, fertilizers, machinery and modern varieties of crops; or use sustainable agriculture, promoting improved traditional, small-scale techniques (Pretty, 1999).

13.1. Introduction

Diseases of dairy cattle cause huge economic losses. The losses are associated with lower productive and reproductive performances as well as mortality of the valuable animals. The high producing animals are susceptible to various infectious and contagious diseases. The diseases may permanently affect the performance of the animal e.g., mastitis may permanently damage the quarter(s) of the udder. Thus the culling rate of the herd may increase which affects the profitability of the farm. The occurrence of diseases in cattle is preventable. So, steps are needed to prevent the occurrence of diseases as prevention is better than cure. A number of factors are associated with the occurrence of diseases in animals. Disease prevention and control involves measures designed to prevent or reduce as much as possible the incidence, prevalence and consequences of the disease. These measures can be applied to control the reservoir of infection, break route of transmission or reduce the numbers of susceptible. Various new and environment friendly methods have been developed by modification or refinement of the old methods of disease control and prevention.

12.1. Introduction

Milking is the crucial operation in a dairy farm, as milk is the main source of revenue of a dairy farm. Milking is a labour intensive operation. About 50-60 percent of the total time of farm operation is required for milking and allied activities. Milking is an art which requires skill, patience, efficiency and experience. It should be handled quietly, quickly, gently, cleanly and completely, by avoiding any type of pain, annoyance or inconvenience to the animals. Possession of high yielding animals or good managemental conditions will not generate profit if the milking operation is inefficient.

1.1. Introduction

A typical dairy farm consist of different classes of dairy animals like calf, heifer, breeding heifer, pregnant, milch and dry animals and bull. The systems of management for the different classes are not same. They need some routine as well as periodical farm practices, some of which are common for all categories of animals (i.e., identification, dehorning, grooming etc.), while some categories need special farm operations (e.g., castration in males, milking etc.). Also there is need of routine disinfection of animal sheds and farm premises to prevent and control occurrence of diseases and maintaining the animals healthy. Further for proper execution of all these operations there is need of keeping farm records.  Keeping in view the above points, this section deals with some important farm management practices.

10.1. Introduction

During last few decades dairy animal production has been intensified several folds, along with this reproductive problems have also increased. For efficient dairy animal production, the cow should show regular reproductive activities like cyclic breeding activity, pregnancy at appropriate time, give birth of a live healthy calf and again pregnant after sometimes. If any of these activities are inadequate, then it substantially affects the profitability of the farm. There is an ample scope of improvement of these reproductive setbacks through traditional breeding, feeding and management. However, reproductive problems can be minimized by the use of recently developed reproductive techniques. It not only minimizes reproductive problems, but also improves the reproductive efficiency of the dairy herd and better exploitation of the genetic potential of high merit animals.

9.1. Introduction

Reproduction is an important event in the life of an animal (both male and female). The success of a dairy farm depends on the reproductive efficiency of cattle which depends on the efficient reproductive management. The animals should be reproductively sound. The cow should be a regular breeder with calving interval of 12-13 months to minimize the generation interval and to increase the profitability of the dairy farm. The bull should have high libido, produce good quality semen with high fertility rate.

8.1. Introduction

Providing appropriate nutrition is an elementary step in dairy animal production. Improper nutrition prevents cattle to express full genetic potential for milk production and reproductive efficiency. Nutrition helps in maintaining good health condition of the animal.

Therefore, one should know the basic digestive physiology, various types of nutrients and their requirements in different categories of animals present in a dairy herd. As feed cost contributes principal expenditure of a dairy farm, balanced ration should be prepared in a cost effective manner. Proper understanding of feeds and rations also help to explore alternative feeds and supplements without hampering the health as well as productivity of the animals. Effective dairy farming requires converting feed into milk which worth more than the total cost of production (mostly contributed by feed cost).

7.1. Introduction

The lactating cows are important assets of a dairy farm. The profitability and viability of the dairy farm mainly depend on the overall milk production. The lactation cycle of the cow can be divided into different phases for efficient management as milk production, DM intake and body weight vary considerably during the different phases. In the early lactation, lactating animals loose body weight drastically and they are prone to various metabolic disorders. Efficient nutritional management during lactation is required to support the high milk production, persistency of lactation and health of the cows. Another most important event is the post partum oestrus and subsequent conception, which depends on the care and management of the cows during this period. Therefore, proper care and management of the lactating cows are essential to harvest maximum amount of milk from healthy cows in a sustainable way.

6.1. Introduction

Care of cows at and after calving is vital for successful birth and maintaining the cow and calf in proper health condition. Calving is a high risk event in terms of both cow and calf health, and is associated with most of the health problems. New born calves are born sterile and it gets infection from the surroundings which depends on the maintenance of hygienic environment and care of the just after birth. The fresh cows are susceptible to a number of metabolic diseases and infections due decrease immune status of the cow. Preparation and care during this period will minimize sickness and death of the cow and calf.

5.1. Introduction

A dry cow is a cow that is not producing milk. Usually cow remains in-milk for about 305 days (average lactation length), after that it remains for a period of about 60 days in dry condition (not giving milk) called dry period. Dry period is critical for a cow for regeneration of her udder and reserve nutrients for the next lactation, otherwise, milk production will not be upto the mark and the cow may suffer from several metabolic diseases after parturition. A dry cow is just as valuable as a lactating cow, therefore should be not neglected. A dry cow management programme includes nutrition, general management and health control programme.

4.1. Introduction

Heifers are young female cattle from 12 months of age to first calving. Heifer management is important as they are future cow of the herd. Proper growth and body condition of the heifers are associated with their early sexual maturity and age at first breeding, and their later productive and reproductive performances, when they become cow. Thus, proper care and management of the heifers is necessary to establish a good dairy herd.

3.1. Introduction 

Calves are the future replacement stock of dairy farm. The raising of calves, an important operation of the dairy farm requires a great deal of managemental skill, application and constant attention. Any negligency results in increased calf mortality, poor growth and development of the calves. So, care of the calves is important for success of the dairy farm.

2.1. Introduction

A system of housing is more or less synonymous to the system of management of dairy cattle. Housing is essential to protect the animals from extreme climatic conditions, wild animals and theft. Housing also helps to maintain normal health of the animal by proper feeding, watering and reducing environmental stresses. An efficient housing system ultimately leads to an efficient management and reduce labour requirements to the minimum.

1.1. Introduction

Dairy animal production in the last few decades witnessed tremendous growth throughout the world. The remarkable success of the dairy animal production can be attributed to the constant efforts of researcher, planner as well as producer. At present dairy farming is becoming a commercial activity. Hi-tech dairy farms produce high quality milk for making value added milk products for competitive markets around the world. The management of the dairy farming enterprises is crucial for the sustainability and profitability of it. The effective management of dairy animals essentially emphasizes the following areas:

Theory

Statistics: Collection of methods for planning experiments, obtaining data, and then organizing, summarizing, presenting, analyzing, interpreting, and drawing conclusions.

Sir R.A.Fisher: Father of modern statistics.

Population: All subjects possessing a common characteristic that is being studied.

Sample: A subgroup or subset of the population.

Parameter: Characteristic or measure obtained from a population.

Statistic: Characteristic or measure obtained from a sample.

Karl Pearson: Study of correlation and chi-square test of goodness of fit.

W.S.Gosset: Student’s t-test for small sample

Francis Galton: Regression analysis.