eChapters

Cancer cryosurgery began in England during 1850s, when James Arnott used local application of salt solutions containing crushed ice to treat advanced cancers in accessible sites, such as breast and the uterine cervix. Since then, landmark advances in chemistry, physics, material science, and biology have culminated in the sophisticated cryosurgical devices currently in use.
 
Cryosurgery is defined as a method that uses the local application of extreme cold to destroy abnormal or diseased tissue, with the possibility of the maintenance of normal adjacent tissue. Normal tissue can be maintained because the extension of the ice ball can be controlled. Tissue temperature should reach -20^o C or below. Attempts should be taken to kill all tissues in the target with minimal damage to surrounding tissues. There is a variable response of tissues to cryotherapy based on density, vascularity and the water content of the tissue, temperature and size of the cryoprobe, spray rate, rate of freeze, rate of thaw and number of freeze and thaw cycles. It is ideal to have quick freeze and slow thaw for maximum benefit. The extent of freezing should be closely monitored, with either temperature monitoring probes or by visual inspection and palpation of frozen area and this is more advantageous in case of relatively small lesions.

Definition : Soil microbiology is the study of microorganisms living in soil which complete whole or some part of their life cycle in soil. They include both beneficial as well as deleterious microorganisms but as a specialized branch main thrust is laid on their metabolic activities and the role they play in energy flow, cycling of nutrients associated with the primary productivity and soil ecosystem development. Besides, it focuses on environmental impact, whether favourable or unfavourable, on soil microorganisms and the various soil biochemical processes mediated by various microbes. A clear understanding of the interactions between soil microbial communities and elemental soil components is imperative to comprehend total ecosystem function. Atlas and Bartha have defined the soil microbiology as ‘the study of organisms that live in soil; their metabolic activity; their roles in energy flow; their roles in nutrient cycling’. As per Tate soil microbiology involves ‘the study of soil ecosystem which is the product of intricate interactions between physical and chemical matrix of highly variable composition and living communities of all form’.

The plant roots, soil animals and microorganisms make up soil biological communities, accelerate biochemical activities through intra- and extra-cellular enzymes and interact in such a manner that biogeochemical cycling on this earth continues uninterrupted. Without intermeshing vital processes of soil microflora, microfauna and associated mesofauna, the soil would have become a repository of plant residues and animal remains with no facility for recycling the vital nutrients for plant growth, thus halting the whole process of geo-chemical recycling in nature. Though living component rarely makes up more than 4% of the total soil organic carbon, it plays vital role in geochemical recycling, soil development and ecosystem stability.

Soil is the outer loose layer of earth consisting of layers of mineral material (regolith) whose properties differ from one another and these differences are largely due to the variation in biological activities. Soil micro-environment principally comprizes of inorganic particulates (sand, silt and clay) plus certain oxides and hydroxides, plant roots, organic matter, microbial biomass and aqueous and gaseous phases. The uneven distribution of these components provides a great variety of conditions from field to micropores. The interaction of physical and chemical factors contributes to the creation of varied soil habitat and hence determines the composition and activity of soil biota at a particular site and time. Over geological times, microorganisms have had great opportunity to become distributed worldwide. Such growth and development of microorganisms as well as species diversity is of considerable significance. The existing geographic distribution is reflective of long term adaptation of microorganisms to the various environmental conditions. The preferred environment of an organism is usually referred as ‘habitat’.

The study of soil microorganisms involves various complicacies when compared with those of plants or animals aboveground. The complicated heterogeneous environment existing in soil and the varied growth behaviour of microbial populations in soil have necessitated the development of special techniques to study the microbes and their metabolic diversity, individually and holistically without disturbing their natural habitat. With the gradual improvement in microscopy since its discovery in 1667 and also with the greater understanding of the nature of soil microbes and their properties in relation to total ecosystem function, the concept of studying microbes in isolation has enormously changed. Microscopes have helped in magnifying these, otherwise invisible, minute creatures within the limits of naked eyes.

Soil microorganisms in true sense are one of natural safety valves that regulate biogeochemical transformations in soil ecosystem. They act as natural agents for the disposal of organic matter. The various essential biological elements such as C, N, S and P, apart from H and O, form the primary building blocks of cells and their constituent elements are recycled through tiny microorganisms present in soil. More they are in quality and quantity, better recycling is expected by them. The organically bound materials are converted to simpler inorganic forms to complete biological cycle initiated during photosynthesis and other anabolic processes.

Nitrogen ranks fourth element in cell composition after C, H and O. It forms main components of amino acids, the building blocks of peptides and proteins. Besides, it is present in the genetic material of cell as well as in the chlorophyll and cell wall in the form of chitin and mucopeptides. Plant growth in soil is often limited by less supply of nitrogen, therefore a major nutrient limiting factor in crop production. About 26 x 10⁶ Mg N is globally applied to soil each year to enhance crop productivity.

Phosphorus, an essential element, plays a central role in cell metabolism and reproduction. It is a structural component of energy transferring molecules (ATP, ADP and AMP), nucleic acids, coenzymes, phosphoproteins, phospholipids and sugar phosphates. In soils, the phosphorus does not occur as abundantly as nitrogen or potassium. The total phosphorus in an average arable soil is estimated to be about 0.05% (by weight) with an average of approximately 1100 kg P ha-1 (range 200-2000 kg P ha^-1). But only a meager proportion (only ~0.1-1.0%) of it is available for use by plants and microorganisms because phosphorus has poor solubility and gets fixed in soil. Not only the native inorganic phosphates but even the added soluble phosphates of fertilizers and manure readily combine with the cations present in soil solution to form low solubility products. Fixation reactions in soils allow only a small fraction (10-15%) of phosphorus fertilizer to be taken up by the plants in the year of its application.

Sulphur in nature follows similar cycle as that of nitrogen and shares many common features with it. In soils, decomposition of organic matter releases major portion of nitrogen and sulphur bound in proteins, as cystine or methionine amino acids, or vitamins, etc. In proteins, on an average, for every 36 atoms of nitrogen one atom of sulphur is present. Mineralization supplies a large fraction of nitrogen and sulphur to the plants. Secondly, both nitrogen and sulphur have several chemical forms under different soil conditions (Table 8.1) and both are subject to microbial reduction. Thirdly, both can enter or leave soil in gaseous form and both are subject to some degree of leaching in the anionic form.

Soil microorganisms immobilize and mineralize various elements to satisfy their growth requirements. The subsequent turnover of microbial biomass also releases several mineral elements. The elements may be released as a result of organic matter decomposition (e.g. during the process of mineralization, ammonification, etc.) or through biological weathering. Other transformations may involve oxidation and reduction of various inorganic ions and compounds which are mostly catalyzed by chemoautotrophic bacteria during oxidation of ammonium, nitrite, sulphur, iron, etc. Such oxidations may also release energy for microbial growth.

Mycorrhizae denote the symbiotic associations between plant roots and fungal mycelia. Literally it means fungal root. In 1840, Vittandini proposed that ‘tree rootlets are nourished by certain fungal mycelia which mantle them’. The first illustrations of mycorrhiza were published in the same year by Robert Hartig. However, in 1885 A.B. Frank coined the term “mykorrhizen” to the mutualistic symbiotic fungal association of roots (‘mykos’ fungus ‘rhizen’ roots). He characterized the sheath-forming fungi on tree as ‘ectotropisch’ (ectotrophic) and those without such compact sheath as ‘endotropisch’ (endotrophic). Fossil records reveal that mycorrhizae are as old as terrestrial plants.

Soil is a living entity having dynamic physico-chemical and biological properties. Besides supporting the growth of various biological communities, it also serves as a medium on which the organic residues, in the form of dead plant and animal or their excretions, are degraded and decomposed. The biological properties to soil are endowed through the interactive activities of plant root, soil microbes and soil animals. The soil organisms live in a constant state of competition and have to struggle hard for their survival. In this struggle some species become dominant and some remain sub-dominant and others perish or remain in very low profile. So a sort of dynamic equilibrium is the net result of wide range of interactions occurring both at organism and population levels amongst different components of soil biota. Many interactions are short-lived and sporadic and others are more stable.

Soil is inhabited by incredibly diverse living microorganisms that are significant to plant growth and development. Soil microorganisms produce a variety of metabolites, probably several thousands, which influence the plant growth either positively or negatively. Therefore, in such a complex situation, identification of any one metabolite or a compound as active phytohormone or phytotoxin is really an uphill task. Appropriate extraction procedure, knowledge about the proper site for its action, appropriate conducive physiological environment and the effective intensity or concentration is of prime importance. Compounds, in general, are inhibitory to growth at higher concentrations but usually stimulatory at lower concentrations. All growth regulators, irrespective of their provenance or structure, may be divided into two groups.

The soil microorganisms thrive on organic matter in soil by feeding readily on soluble substrates and rather slowly on insoluble substrates. Organisms derive carbon and energy during the process of organic matter decomposition and release organically-bound carbon, thereby decrease C :N ratio and utilize nutrients. Any decrease in organic matter content in soil is likely to affect the microbial biomass and their activities thereby influence the soil fertility and productivity. It is, therefore, imperative to recycle the organic matter in soil in whatsoever form it may be. The raw organic matter requires appropriate treatment to boost decomposition process.

In agricultural practices pesticide application is an inevitable factor for maintaining high crop productivity and is currently an integral part of modern farming. Pests (insects, microbes and weeds) cause approximately 20-30% loss in crop production so making pesticide use indispensable for crop protection.
 
Pesticide : A pesticide may be defined as ‘any agent or chemical or a mixture of chemicals/ substances intended to prevent, destroy, repel or irritate one or more pest populations causing economic loss in crop production’. Worldwide more than 450 active pesticide chemicals formulated into more than 10,000 commercial products are currently used by farmers. The most worrying aspect is that about two-third of the 800 chemicals tested so far have been found involved in causing or promoting tumor in rodents. Yet more than 50,000 synthetic chemicals/formulations remain untested so far.

Boost to crop production has been the ultimate goal of researchers involved in agriculture so as to feed the ever-increasing human and domestic herbivorous animal populations. Crop production is not only constrained by the limited inherent potential of available varieties currently in use, but is also largely affected by the limitations of soil nutrient availability and damages by diseases, insects and weeds. To counter later challenges, augmentation of soil nutrients through use of biofertilizers in integrated nutrient management programmes and restricting the use of chemical pesticide by integrating biopesticides in plant protection programmes has received much attention in recent years because of consumer’s preference for organic food.

Biotechnological research started in early seventies with some impressive discoveries in the field of genetics, microbiology, biochemistry, biology and chemical bioengineering. The amalgamation of these sciences particularly integration of their basic principles and applied aspects gave rise to a new field, completely diverse and versatile in nature, what we call today ‘biotechnology’. Originating from research laboratories in universities, biotechnology rapidly captured the attention of industries as the number of its potential products increased. This newly developed frontier science later found broad application in medical science, pharmaceutical industry, agriculture, veterinary sciences and chemical industry for the welfare of mankind. Biotechnology by definition means ‘any technique that uses living organism or a part thereof to make or modify a product, to improve plant or animal or to develop microorganisms for specific purposes’.

THEORY
    ·    Father of Extension: James Stuart
    ·    Word Extension: Derived from Latin roots “ex”    - Out
                                                              tensio”    - Stretching
    ·    Extension term originated in England as University Extension in 1866.
    ·    The term Extension Education first used in 1873 by Cambridge University.
    ·    Philosophy of Extension (Kelsey and Hearne, 1967): How to think.
    ·    Binet test: Intelligence test (IQ).
    ·    Function of Extension: Change in Attitude, Skill and Knowledge of an individuals.
    ·    Extension Education Process:  Extension education is a participative and continuous process.
    ·    Learning Situation: It is a condition or environment in which all the elements necessary for promoting learning are present. 
    ·    Elements of effective learning situations in Extension are:

Theory
The Constitution of India related to women:
    ·    Guarantees to all Indian women equality: Article 14
    ·    No discrimination by the State: Article 15(1)
    ·    Equality of opportunity: Article 16
    ·    Equal pay for equal work: Article 39(d)
    ·    Securing just and humane conditions of work and for maternity relief: Article 42
    ·    The All India Women’s Education Conference was held in Pune in 1927. 
    ·    The National Policy For the Empowerment of Women came was passed in 2001
    ·    In 2010 March 9, Rajya Sabha passed the Women’s Reservation Bill requiring that 33% of seats in India’s Parliament and state legislative bodies be reserved for women

Theory
    ·    Father of sociology: Auguste Comte 
    ·    The term sociology was coined by Auguste Comte (1789-1875).
    ·    Sociology word comes from two roots i.e.     
        Latin word ‘socius’ meaning companion         
        Greek word ‘logos’ meaning speech or reasoning.
    ·    Sociology: Sociology is the scientific study of human social behavior and its origins, development, organizations, and institutions. It is a social science that uses various methods of empirical investigation and critical analysis to develop a body of knowledge about human social actions, social structure and functions.

Theory

Research: The word research is composed of two words “Re” and “Search”.
“Re” - ‘Again or over again or a new’ 
“Search” - ‘To examine closely and carefully’ or ‘to test and try’. 
Research is a careful, systematic, patient study and investigation in some field of knowledge undertaken to establish principles / policies. 
Science: It is a systematized knowledge derived through observation, experimentation or any other systematic method or procedure in order to determine the nature of phenomenon or process being studied or the causes behind specific events.

Theory

Communication word comes from Latin ‘Communis’- Common
Communication: The communication is the process of human interaction in which one person communicates a message/idea to another person. 
Diffusion: It is the process by which an innovation/new idea/new technique spreads. 
According to Rogers (1983) ‘Communication is the process by which the message is transmitted from the source to the receiver’.

Theory

Extension Teaching Methods: Methods by using them new information can pass freely between the extension worker and rural communities. Extension education is mainly concerned with the dissemination of useful and practical information relating to rural life and helping the rural people in the practical application of such knowledge to rural situations. Extension teaching methods can be classified on the basis of:

Theory

Rural Development: The economic betterment of people as well as greater social transformation. The efforts for rural development comprises the direct and indirect involvement of people at the grass root level for development of agriculture/animal husbandry, industry, communication, education, health and allied sectors. 
Democratic Decentralization: To ensure people’s participation in rural development programmes, democratic decentralization has been the core principle of the government since 1957. In the process, people’s participation in all developmental activities has been the unique phenomena to find out the solutions of their problems.
Panchayat Raj: On the principle of democratic decentralization, Panchayat Raj institutions were launched in 1957 as per the recommendations of Balwant Rai Mehta Committee. Under this, the government has derived its authority from the people, and distribute to some extent to the people for decision and action at the local level called Panchayat Raj.

Theory

  The term ‘Management’ derived from word ‘manage’ derived from French word menage means ‘housekeeping’.

 According to Knootz and Weihrich 1988, ‘Management as the process of designing and maintaining an environment in which individuals, working together in groups, efficiently accomplish selected aims’. 

According to Louis E.Boone and David L.Kurtz ‘management as the use of people and other resources to accomplish objectives’.

POSDCORB is an acronym widely used in the field of Management and Public Administration., it first appeared in a 1937 staff paper by Luther Gulick and Lyndall Urwick. The acronym stands for steps in the administrative process: Planning, Organizing, Staffing, Directing, Coordinating, Reporting and Budgeting.

Theory

ICT or Information and Communications Technology: The basket of technologies, which assist or support in storage, processing and dissemination/ communication of data/information. ICT thus includes technologies such as desktop and laptop computers, software and connection to the Internet that are intended to fulfil information processing and communication functions.

ICT Tools

    •    Word processing applications - used for preparing text documents.
    •     Presentation software - used for preparing presentations
    •     Spreadsheets - used for calculation and preparing tabular data with calculations
    •     Databases - used to store the information in the form of records and retrieving information using query mechanism.
    •    Multimedia – used to organize the information more meaningful manner with the help of text, images, animation, audio and videos
    •    Web browsers and E-mail – used to searching information and sending or receiving mail using Internet.

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.

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:

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.

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.

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.

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.

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.

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.

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).

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.

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.

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.

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.

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.

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).

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.

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.

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.

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.

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.

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.

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.

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.

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).