eChapters

Whenever the daily maximum temperature exceeds more than average values during summer season the heat wave will occur. Similarly, whenever the daily minimum temperature falls below the average values cold wave will occur. The India Meteorological department has developed the criteria to identify the occurrence the heat waves and cold waves.

11.1 Heat Waves

Heat wave is defined as the condition when the daily maximum temperature is 45ºC or more. Based on departure from normal daily maximum temperature of 40ºC onwards the heat waves are defined as follows:

Drought is a situation when the demand for water is much greater than the availability of water. Drought is a creeping phenomenon and it is experienced only after it has set in. The scarcity of water compared to demand will have greater impact on every activity of human life including failure of crops, food shortages, decline in ground water table, drying tanks, lakes or reservoirs, acute shortage of drinking water for humans and livestock shortage for cattle etc.

Drought will have very serious impact on economy of households as well as that of nation. There are five different types of droughts depending upon the nature of shortage of water

10.1 Meteorological Drought

Meteorological drought occurs when the water received through rainfall during a given period is much less than long period average rainfall of the area. The meteorological drought is associated with either failure of rain or due to long gap between the successive rainfall events. In India, meteorological drought occurs due to failure of south west monsoon or long breaks in south west monsoon rainfall. In Tamil Nadu the drought occurs due to failure of north east monsoon rainfall during months of October to December.

The division of earth’s climates into worldwide system of contiguous regions, each one of which is defined by relative homogeneity of the climatic elements (Fig. 9.1)

9.1 Koppen’s Classification

Koppen’s climatic classification describes 5 major groups of climate A, B, C, D and E which are sub-divided into a total of 14 individual climate types, along with a special category of Highland (H) climate.

A - Tropical: Average temperature of coldest month is 18°C or more.

B - Dry climate: Potential evapotranspiration exceeds precipitation.

C - Warm temperature: The average temperature of the coldest month (of the middle latitudes) is higher than -3°C but below 18°C.

The general circulation of the atmosphere explains the formation of pressure belts and wind systems in the earth’s atmosphere. It is known that the earth receives more solar radiation near the equator and gets heated more. Consequently, the air gets heated more and rises vertically upwards. As there is more convection of the air near the equator, the atmospheric pressure will be less. The warm air which moves upwards up to a height about 14 km near the equator gets cooled and move towards the poles.

The upper air gets gradually cooled when it reaches a latitude of 30°N in the northern hemisphere and 30°S in the southern hemisphere. At about 30°latitude the cold air descends to the earth’s surface. Some of the cold air after descending to earth’s surface moves towards the equator. The circulation of air between the equator and 30°N or 30°S latitudes is called Hadley cells (Fig. 8.1).

The winds blowing from 30° latitude towards the equator at surface level are called trade winds. These trade winds which move towards the equator in both northern hemisphere and southern hemisphere converge near the equator and the zone of the convergence of these winds is called Inter Tropical Zone of Convergence. As the convergence of air takes place, due to convection of heat as a result of high temperatures leads to vertical lifting of moist air. Therefore, the Equatorial regions receive more rainfall and there are tropical forests in this region.

Clouds play very important role on weather and climate. The formation of clouds takes place when water condenses in the sky. Clouds are visible accumulation of tiny water droplets and ice crystals in the Earth’s atmosphere. The moisture is always present in the atmosphere though it may not be visible. Clouds form when air becomes cooler until the water vapour present in it condenses to liquid form. The condensation over oceans occurs around solid particles like salt, dust, smoke etc. suspended in the atmosphere. The type of clouds depends upon temperature and wind. The clouds are classified based on physical appearance and the height at which clouds are formed (Fig. 7.1).

Clouds play very important role on weather and climate. The formation of clouds takes place when water condenses in the sky. Clouds are visible accumulation of tiny water droplets and ice crystals in the Earth’s atmosphere. The moisture is always present in the atmosphere though it may not be visible. Clouds form when air becomes cooler until the water vapour present in it condenses to liquid form. The condensation over oceans occurs around solid particles like salt, dust, smoke etc. suspended in the atmosphere. The type of clouds depends upon temperature and wind. The clouds are classified based on physical appearance and the height at which clouds are formed (Fig. 7.1).

The mass of a body is usually defined as the material content of the body whereas the weight of the body is defined as the force with which the body is attracted towards the earth due to gravity. Therefore, the weight of a body is the product of its mass and acceleration due to gravity. The air in the atmosphere, which is a mixture of several gases has certain mass and although not very dense, will acquire some weight due to gravitational force of attraction when the entire column of the atmosphere from the ground level to the top of it is considered. Pressure is defined as the force for unit area. Therefore, the atmospheric pressure is defined as the force exerted by an air column of units area of cross section extending from earth’s surface to the top of atmosphere. As we go up in the atmosphere the height of the air column decreases, the air also become rarer and the atmospheric pressure decreases with increase in height.

In meteorology, temperature is always referred to as the temperature of the air unless it is stated otherwise. There will always be exchange of heat in the atmosphere from a point at high temperature to a point at lower temperature. The transfer of heat through convection and radiation is always observed in the atmosphere whereas the conduction of heat takes place near the earth’s surface.

4.1 Diffusion of Heat

Heat diffuses (spreads) at different rates through different media, the rate at which diffusion of heat takes place is called thermal diffusivity. The thermal diffusinty of of some selected materials is given below:

One can see from the above table that iron has got higher diffusivity compared to wood. Suppose one end of iron rod is kept at hot temperature, the heat spreads faster in iron rod and the other end gets warmer quicker than in the case of a wooden stick which means that the transfer of heat is quicker in bodies with higher thermal diffusivity.

Three fundamental processes that are responsible for inducing changes in weather are transfer of heat, energy and mass. The Sun, whose inter-surface temperature is estimated to be around 6000°C emits heat energy in the form of solar radiation which is received at the earth’s surface after it is partly depleted in the atmosphere. Therefore, it is essential to understand the processes that govern the transfer of heat in the earth-atmosphere system.

3.1 Conduction

The transfer of heat from one point to another point within the material medium without the actual movement of the particles in the medium is called conduction i.e. the heat energy transfer is conducted by the particles in the medium from hot end to cold end. If a metal rod is heated at one end, the other end of rod becomes hot gradually due to transfer of heat by conduction. In the earth atmosphere system, conduction of heat is observed at the ground surface only. The amount of heat energy transferred due to conduction (Q) is

Air is one of the primary things that make life on earth possible. The earth’s atmosphere or air is made up of variety of gases and other particles. The dynamic layer surrounding the earth’s surface containing various mixture of gases, moisture and solid particles (aerosols) is called atmosphere. The atmosphere is generally defined as the gaseous envelop surrounding the earth.

The formation of the earth was believed to be about five billion years ago. In the first 500 million years, a thick atmosphere emerged from the vapour and gases that were expelled from the interior of the earth. Hydrogen (H2 ), water vapour, methane and carbon dioxide were some of the gases believed to be initially formed in the atmosphere due to out gassing from the interior of the earth. About 3.5 billion years ago, the atmosphere consisted of carbon dioxide (CO2 ), Carbon monoxide (CO), water vapour (H2 O), nitrogen (N2 ) and hydrogen present in atmospheric layers like troposphere, stratosphere, mesosphere, thermosphere (Fig. 2.1). The condensation of water vapour into water led to the formation of oceans in which sedimentation occurred and the hydrosphere was created. In the initial and ancient environment, oxygen was not present. Anaerobic is technical word which literally means without air (where air is generally used to mean oxygen and aerobic indicates the presence of oxygen). Evidence of such an anaerobic reducing atmosphere was hidden in early rock formations such as iron and uranium in their reduced states.

Aristotle (384 to 322 BC), an ancient Greek philosopher and scientist (Fig. 1.1) developed the concept of meteorology as a study of the lower atmosphere. Over the years meteorology developed as a science of atmosphere which deals with the physics, dynamics and chemistry of the atmosphere and their effect upon the earth’s surface, oceans and thereby life in general either directly or indirectly.

As the atmospheric conditions change from time to time in a given area and from place to place in a given time, climatology was developed as a science which studies the average conditions of the weather and its variability over a long period of time.

All most all the human activities are greatly influenced by the weather and climate to a greater extent. Therefore, the scope of meteorology encompasses various activities which are of considerable economic significance as detailed here below;

1.1 Housing

The design and construction of houses, buildings, industrial structures etc. depends upon the weather and climate of the region. Orientation of doors, windows roofs of the buildings are usually designed to provide maximum comfort and convenience to the people.

Sustainability is one of the main guiding principles for our modern societies. Water and sustainable development are closely linked since the provision of water is sufficient quantities and of high quality have important impacts on our environment, society and industry as well as the well-being of next generation.

Nowadays, there are several emerging problems and risk that affects the sustainable management of water resources. Pollution diffusion pose major threat. Water resources and demand for water remain unbalanced at various levels. Groundwater abstraction and over exploitation have serious environmental impacts. Reservoirs for water storage, flood control, recreation and energy production remain controversial. Climate change on the other hand is creating lot of impact on both water availability and water demand. These problems have not only physical, chemical, biological and ecological dimensions but encompass also important socio-economic issues such as, regulatory framework for water resources management, methods to balance conflicting human and ecosystem demand, financial sustainability of water management system. This shows the complexity water managers face for sustainable management of water resources and the need to shift from strong traditional, local and regional water resources management approaches to more integrated river basin approaches dealing with uncertainties in environmental conditions, societal development and global change.

The diffusion of need-based appropriate technologies involves strategically promoting and implementing innovations that meet the specific needs of a community. Utilizing various interactive and engaging techniques such as methods demonstration, group discussion, role play, and exhibitions can significantly enhance the effectiveness of this process.

A demonstration is an educational technique that involves showing or presenting a process, product, or concept in action to an audience. The primary goal of a demonstration is to provide a clear, practical example that enhances understanding and encourages the adoption of new practices or technologies. Demonstrations are often used in educational, training, and outreach programs to effectively convey information and skills.

Extension workers are required to visit farm homes as a fundamental aspect of effective Extension work. These visits are essential for building trust and securing the cooperation and friendship of farm families, especially in areas where the value of educational programs is not fully understood, where group meetings are uncommon, or where cultural norms prevent women from meeting publicly. As an Extension worker, reaching all members of the community involves employing various methods. While individual visits may not reach as many people as other approaches, there are occasions where only a personal visit will suffice. Words can be misunderstood, but a friendly smile, genuine empathy, or practical assistance are universally understood. It is crucial for Extension workers to be liked by families, as this acceptance is necessary for the families to accept their recommendations. Establishing rapport takes time; understanding local customs and observing social niceties during visits can significantly impact their success. For example, sharing tea with a family can be a critical gesture.

The recent social, political, and economic challenges worldwide necessitate the adoption of new strategies by governments and development agencies to enhance people's livelihoods. These challenges underscore the importance of understanding and appreciating the growing significance of livelihood issues, particularly sustainable livelihood mechanisms. Addressing issues such as poverty, hunger, food security, gender equality, and economic growth—which are central to the Sustainable Development Goals (SDG 17)—requires a comprehensive understanding of the complex nature of livelihood challenges, livelihood diversification, and sustainable livelihood strategies.

Governments and non-governmental organizations, especially in developing nations, are under increasing pressure to develop coordinated strategies and interventions aimed at livelihood diversification. These efforts are crucial to sustainably improve the livelihoods of the poor, disadvantaged, vulnerable, and excluded populations.

Communication, as a fundamental aspect of human existence, has evolved significantly over time. Initially, it was primarily visual and verbal, but with the development of written scripts and digital technologies, these too became integral components of human interaction. Language has always been inherently complex, with individuals from different cultural backgrounds and belief systems encoding and decoding messages in diverse ways. This process involves giving meaning to and deriving meaning from various forms of communication.

Moreover, the medium through which communication occurs often imposes its own structural rules or "grammar." For instance, messages conveyed through audiovisual media or computer-mediated communication are often organized differently than those in traditional written or spoken forms. These structural differences can lead to variations in meaning depending on the context in which the communication takes place.

Healthcare programs across many countries, particularly in developing nations, increasingly employ Behavior Change Communication (BCC) to enhance the health status and well-being of populations. BCC is a process designed to motivate individuals to adopt and maintain healthy behaviors and lifestyles. An effective BCC strategy plays a crucial role in implementing activities aimed at improving population health. Notably, BCC is a healthcare education strategy outlined in the Uttar Pradesh National Rural Health Mission (NRHM) with goals including reducing mortality, fertility, and morbidity.

Upon completion of this unit, learners should be able to:

• Explain the meaning and benefits of BCC in family healthcare.

• Discuss various channels of BCC.

• Formulate BCC strategies.

• Follow guidelines for successful BCC implementation.

Reports predict that 2050 will be a critical year for global agriculture, with the human population expected to increase by 50% compared to current levels (Future Farms, 2021). India is projected to become the world's most populous nation by mid-century, with an estimated population of 1.6 billion people. This demographic surge will necessitate a 70% increase in food production, underscoring the enduring importance of food security as a primary agenda for agricultural research in the coming decades.

For states that heavily rely on imports for essential commodities such as rice, fruits, and vegetables, it will be crucial to enhance the production and productivity of major crops to mitigate any external shocks in production or demand. This challenge is compounded by the imperative to conserve and optimize the use of natural resources. Recent studies indicate a 6.93% decline in average groundwater recharge in the state over the past decade. Additionally, the increasing pressure to convert agricultural land for non-farming purposes is expected to continue.

Agriculture constitutes the primary source of income in rural India. Rural women play a pivotal role in various agricultural practices, encompassing activities such as planting, harvesting, and post-harvesting operations. Additionally, their responsibilities extend to producing agricultural crops, tending to animals, processing and preparing food, engaging in wage labor within agricultural or other rural enterprises, collecting fuel and water, participating in trade and marketing, caring for family members, and maintaining their homes (Klasen and Lamanna, 2009).

The engagement of rural women in agriculture is extensive and multifaceted, covering a wide range of activities that are vital for household sustenance and community welfare. These activities are essential not only for economic stability but also for food security and overall rural development.

The importance of science and technology (S&T) to rural societies has long been recognized. Despite the significant advancements in S&T in India since 1947, there remains an urgent need to deliver these advancements to the most underserved populations, enabling them to meet the challenges of an increasingly technologically sophisticated world. Technological progress continues to generate new methods of communication and information management, profoundly impacting society. These advancements offer unprecedented opportunities and challenges for scientific endeavors.

While science possesses a universal character, its application is influenced by local customs and values, especially in rural areas where behavior patterns and practices are deeply rooted in traditional beliefs and superstitions. These are not easily displaced by modern scientific approaches. Therefore, S&T policies for rural development must consider the local environment to effectively deliver the benefits of S&T to rural societies. This consideration is crucial for the management of rural natural resources and the environment.

Social change encompasses alterations in both the tangible and intangible aspects of a society's culture. It involves transformations in the structure and dynamics of social systems, manifesting as shifts in:

• The roles assumed by individuals

• The values and norms upheld within society

• The framework of social institutions and structures

• The dynamics of interpersonal relationships

• The patterns of social interaction

• The functions fulfilled by various societal groups and institutions

The most innovative member of a social system is frequently perceived as a deviant by average members and is often assigned a status of low credibility. Consequently, this individual's role in the diffusion process, particularly in persuading others to adopt an innovation, is quite limited. Other members of the system, known as opinion leaders, play a crucial role in providing information and advice about innovations to many individuals within the system.

Opinion leadership refers to the degree to which an individual can influence others' attitudes or overt behaviors informally and with relative frequency. This type of leadership is not derived from the individual's formal position or status within the system. Instead, it is earned and maintained through the individual's technical competence, social accessibility, and adherence to the system’s norms. When a social system is oriented toward change, opinion leaders tend to be more innovative. Conversely, when the system's norms resist change, the behavior of opinion leaders also reflects this resistance. By conforming to the system’s norms, opinion leaders serve as models for the innovation behavior of their followers, thus embodying and reinforcing the system's structure.

Diffusion research investigates the spread of ideas within social groups. It extends beyond the two-step flow theory by examining the factors that influence the adoption of innovations, which can include new ideas, products, or practices, among members of a culture. In multi-step diffusion, while opinion leaders still play a significant role in influencing adopters' behavior, there are also other intermediaries involved in the decision-making process between the media and the audience.

One such intermediary is the change agent, who persuades opinion leaders to either adopt or reject an innovation (Infante, Rancer, & Womack, 1997).

Innovations are not universally adopted by all individuals in a social system simultaneously; rather, adoption typically occurs over time and can be categorized into adopter categories based on the time it takes for individuals to start using the new idea. For change agents, identifying which category individuals belong to is highly practical, as their short-term objective often involves facilitating the adoption of an innovation.

The adoption of new ideas is driven by human interaction within interpersonal networks. When the initial adopter of an innovation discusses it with two members of a social system, and these two in turn influence two more peers, and so forth, the pattern of adoption follows a binomial expansion. Over time, the distribution of adopters tends to follow a bell-shaped curve (Rogers, 1971).

Productivity growth in agriculture is anticipated to drive successful structural transformation and industrialization in pre-industrial developing countries that possess untapped agricultural potential. Historical precedent shows that agricultural revolutions often precede industrial revolutions in countries with predominantly rural populations. Recent industrialization experiences in countries like China, India, and Brazil reinforce this perspective. Achieving productivity growth in agriculture necessitates the availability and adoption of technological innovations within the farming community. In recent years, attention has increasingly focused on understanding the delay between the emergence of promising innovations and their adoption.

Numerous factors contribute to the lack of technology adoption, including credit constraints, limited insurance coverage, high transaction costs, and behavioral biases. Moreover, the availability of information about new technologies is a critical, albeit not sufficient, condition for adoption. Consequently, addressing potential information failures that hinder farmers' adoption of available technologies is essential. This underscores the importance of extension services, as well as the transfer of information through social networks, agro dealers, and commercial partners in the agricultural value chain.

Decisions to adopt innovations are influenced by a complex array of factors, including:

Individual Attributes: Characteristics such as income can significantly impact the decision-making process.

Attributes of the Social System: Innovations may be perceived as violating ethical norms or threatening the privileges of elites within the social structure.

Perceived Attributes of the Innovation: Factors such as the appearance or performance of a new crop variety in a test plot can influence adoption decisions.

Rogers' (1983) model, illustrated in Figure 19-1, outlines the stages involved in the decision to adopt an innovation.

Acquiring information about the value of an innovation is inherently costly. While beneficial innovations exist, there are also numerous unsuitable or harmful ideas. The presence of deceptive salesmen and overly enthusiastic entrepreneurs complicates this process. As noted in Proctus' lament from the epigraph, the challenge lies in employing effective decision-making strategies to maximize the likelihood of adopting beneficial innovations and rejecting detrimental ones, all while acknowledging the costs involved in making these decisions.

Technological change and innovation are fundamental forces shaping our lifestyles, culture, and futures. We devote a substantial proportion of our wealth to research activities that span all areas of society, including agriculture. This investment, particularly in agricultural research, aims primarily to create wealth and conserve natural resources. The returns on our investment in agricultural research—the wealth created and resources conserved—depend significantly on the extent to which primary producers adopt the products of that research.

Maximizing the return on our investment in agricultural research involves identifying which research products are likely to be adopted by primary producers and by how many, as well as determining the processes required to ensure the rapid diffusion of research products among producers. This requires a deep understanding of how research products can better meet the needs of primary producers in their agricultural enterprises.

Within a social system, some innovations diffuse rapidly from initial introduction to widespread use in just a few years. For instance, pocket calculators saw rapid adoption during the mid-1970s. In contrast, other electronic innovations, such as home videotape equipment, have only achieved about 3 percent adoption over the past eight years. What are the characteristics of innovations that influence the rate at which they diffuse and are adopted?

Within a social system, some innovations diffuse rapidly from initial introduction to widespread use in just a few years. For instance, pocket calculators saw rapid adoption during the mid-1970s. In contrast, other electronic innovations, such as home videotape equipment, have only achieved about 3 percent adoption over the past eight years. What are the characteristics of innovations that influence the rate at which they diffuse and are adopted?

The historical origins of diffusion research can be traced back over 200 years. In the early 18th century, French judge and sociologist Tarde wrote "The Laws of Imitation" (1903). He viewed the diffusion of innovation as arising from conscious and unconscious social imitations among individuals. Tarde introduced seminal diffusion concepts such as the S-curve, opinion leaders, and perceived compatibility.

Following Tarde, German political philosopher and sociologist Simmel published "Conflict and the Web of Group Affiliations" (1922). In this work, Simmel explored how the relationships in which individuals are embedded influence their responses to innovations. He also suggested that individuals outside a social system can introduce new ideas into that system.

In the 1920s, American cultural anthropologist Kroeber studied both the spread of innovations and how cultures recursively shape innovations. These early works contributed to the development of diffusion research in sociology during the 1920s and 1930s.

Several independent research traditions have examined the diffusion of innovations. Fields such as anthropology, geography, and sociology have long aimed to understand current behaviours by tracing the diffusion of techniques and ideas from their origins to their present distributions. Critics argue that this tradition often focuses on descriptive history inferred from patterns of similarity (diffusionism) while neglecting causal processes. Extreme diffusionists sometimes postulated implausible links between societies.

Rural sociologists pioneered the quantitative study of innovation diffusion, with classic studies examining the spread of hybrid corn and 2-4-D weed killer in the American Midwest. This field has produced numerous studies, including many focused on the diffusion of modern techniques to Third World peasants. Similarly, researchers in educational reform have studied the spread of kindergartens, driver training, and modern mathematics curricula. Currently, there may be studies on the diffusion of General Education requirements in U.S. universities. Medical sociologists have investigated how new drugs spread among communities of physicians. Additionally, communications and marketing experts study how propaganda and advertising persuade people to adopt new ideas and products.

The significant interest in the diffusion of innovations stems from the challenge of adopting new ideas, even those with clear advantages. A substantial gap often exists between available knowledge and its practical application across various fields. Many innovations experience a lengthy period, sometimes spanning several years, from their initial availability to widespread adoption. Consequently, individuals and organizations frequently grapple with the issue of accelerating the diffusion rate of an innovation.

Diffusion refers to the process by which an innovation is communicated over time through specific channels among members of a social system. This form of communication is distinct in that it involves the dissemination of new ideas. In contemporary society, information technologies like the Internet and mobile phones, which blend mass media and interpersonal communication, serve as powerful diffusion tools. The novelty of the idea in the communication content gives diffusion its unique character.

A. Successful Biological Control Projects

Biological control, the use of natural enemies to manage pest populations, has seen numerous successful implementations globally for example:

1. Control of Cottony Cushion Scale (Icerya purchasi)

The case of the cottony cushion scale, Icerya purchasi, in California's citrus orchards serves as a seminal example of biological control's efficacy. Originating from Australia, this pest posed a severe threat to the burgeoning citrus industry in California in the late 19th century. The story of its control through the introduction of natural enemies is not only a landmark in biological control history but also a demonstration of ecological problem-solving.

Background and Impact

Icerya purchasi is a sap-sucking insect that infests a wide range of host plants but shows a particular fondness for citrus trees. The infestation is damaging as the scale excretes a sticky substance known as honeydew, which promotes the growth of sooty mold, impairing photosynthesis and weakening the plants. The severity of the infestation threatened the economic viability of the citrus industry in California during the 1880s.

A. Mass Production of Quality Bio-control Agents: Techniques, Formulations, Economics, Field Release/Application, and Evaluation

Biological control agents, such as phytophagous insects, play a significant role in integrated pest management by targeting and suppressing weed populations naturally. Effective utilization of these agents requires understanding their mass production, formulation, economics, field release/application, and evaluation.

Techniques for Mass Production of Bio-control Agents

Mass production of bio-control agents involves rearing insects or other organisms in large quantities while maintaining their effectiveness and quality. The following are key techniques used in mass production:

1. Laboratory Rearing: Laboratory rearing of bio-control agents is a meticulous process that ensures the continuous production of high quality insects under controlled environmental conditions. This technique involves creating optimal conditions for temperature, humidity, and light to simulate natural habitats. Nutritional requirements are met by providing specific diets, which can be natural or artificial, tailored to the needs of the bio-control agents. Breeding protocols are established to manage mating, egg-laying, and larval development cycles efficiently. By controlling these factors, laboratory rearing ensures a stable and sustainable supply of bio-control agents for field application.

A. Biology, Adaptation, and Host-Seeking Behavior of Predatory and Parasitic Insects

The study of the biological processes, adaptations, and host-seeking behaviors of predatory and parasitic insects is fundamental for enhancing the efficacy of pest management strategies. These aspects are central to leveraging natural predator and parasite behaviors for biological control.

i. Biology of Predatory and Parasitic Insects

The study of the biology of predatory and parasitic insects is a cornerstone in understanding how these organisms function as critical components of biological control programs. These insects play a pivotal role as natural enemies of pest species, with physiological and developmental traits finely tuned for the effective management of pest populations. By examining their complex life cycles, reproductive strategies, and other biological traits, researchers can optimize the use of these insects in integrated pest management (IPM) strategies.

A. History, Principles, and Scope of Biological Control

Biological Control

Biological control, defined as the use of living organisms to reduce the population of pest species, stands out as one of the most successful, cost effective, and environmentally friendly methods of pest management. This natural process is intrinsic to maintaining ecological balance and supporting the greenery of our planet by enabling plants to produce the necessary biomass to sustain diverse forms of life.

The Essence and Impact of Biological Control

Biological control is an omnipresent force in both natural and human-made ecosystems, constantly active without any human intervention. Its origins trace back over 500 million years with the evolution of the first ecosystems. The process involves naturally occurring reductions in pest populations, which historically, have allowed for the flourishing of plant life critical to the earth’s ecological systems. Without these biological control mechanisms, the amount of energy produced by plants would be a fraction of current levels, drastically reducing the earth’s capacity to support life.

1. Birth weight of rabbit is

a) 80 gms

b) 90 gms

c) 100 gms

d) 110 gms

2. Birth weight of rat is

a) 4-5 gms

b) 1-2 gms

c) 20-30 gms

d) 40-50 gms

1. The most effective method of selection is

a) Mass selection

b) Pedigree selection

c) Progeny testing

d) Selection index

2. The intensity of selection depends with number traits considered ‘n’ is

a) 1/n

b) 1/n²

c) n

d) 1/√n

1. For inbreeding, mated individuals should have common ancestors with in

a) 2-3 generations

b) 4- 6 generations

c) 6-7 generations

d) More than 10 generations

2. Crossing of two inbred lines of the same breed is

a) Incrossing

b) Incross breeding

c) Top incrossing

d) Top incross breeding

1. Heritability in narrow sense is

a) VA/VP

b) VE/VP

c) VG/VP

d) VA+VG/VP

2. Repeatability value set in _________ of heritability

a) Lower limit of h₂

b) Upper limit of h₂

c) Intermediate of h₂

d) Both a and b

1. PhuleTriveni synthetic cattle evolved by the crossing of

a) Holstein x Jersey x Rathi

b) Holstein x Brown Swiss x Gir

c) Holstein x Jersey x Gir

d) Ayrshire x Jersey x Gir

2. Chhota nagpuri breed of sheep is found in

a) Nagpur

b) Uttar Pradesh

c) Jharkhand

d) Gujarat

1. If AAGCT is the base sequence on one side of DNA molecule, what will be complementary sequence on the other side?

a) UUGCA

b) TTCGA

c) AAGCT

d) GGTCA

2. The start codon in the mRNA sequence is

a) AUG

b) UAG

c) UGA

d) UAA

1. Particulate and duplicate nature of heredity factors or element was first demonstrated by
a) Bateson 
b) Mendel
c) Morgan 
d) Punnett
2. The particular site or position of a gene in a chromosome is known as
a) Genotype 
b) Phenotype
c) Locus 
d) Allele
3. Linkage group in swamp buffalo
a) 25 
b) 30
c) 24 
d) 26

56.1. Aim

To determine quality characteristics of dried and dehydrated fruits and vegetables.

56.2. Theory

The quality of dried/dehydrated products can be measured by estimating moisture contents, preservatives level, acid insoluble ash contents and most importantly enzyme reactions.

56.3. Estimation of Acid insoluble ash

1. To total ash add 25 ml of dilute HCl (10% w/w)

2. Cover with a watch glass and boil gently over a low flame for 5 minutes

3. Filter and wash the filter paper thoroughly with hot water

4. Return the paper to the original dish, ignite, cool and weigh the insoluble ash

55.1. Aim

To determine dietary fibres in given samples.

55.2. Theory

Fibres can be classified into four categories like crude fibre (cellulose); acid detergent fibre (cellulose + lignin); neutral detergent fibre (cellulose + lignin + hemicelluloses) and total dietary fibre.

55.3. Procedure for estimation of dietary fibre

55.3.1. Acid detergent fibre (ADF)

Reagents: Cetyl tri-methyl ammonium bromide (CTAB) reagent and Acetone

Apparatus: Digestion apparatus vacuum pump, oven, desiccator and sintered glass crucible.

54.1. Aim

To determine crude fibre in given samples.

54.2. Theory

Fibres can be classified into four categories like crude fibre (cellulose); acid detergent fibre (cellulose + lignin); neutral detergent fibre (cellulose + lignin + hemicelluloses) and total dietary fibre (Cellulose + lignin + hemicelluloses + pectic substances). Crude fibre is the organic residue of a sample. A fat free sample is treated with boiling sulphuric acid and subsequently with sodium hydroxide. The residue after subtraction of ash is regarded as crude fibre.

54.3. Reagents/ Apparatus/Glassware

1. 0.255 N Sulphuric acid solution

2. 0.313 N Sodium hydroxide solution

3. 10% Potassium sulphate solution

4. Ethanol

53.1. Aim

To conduct practical on freezing of vegetables

53.2. Theory

Freezing is often considered the simplest and most natural way of preservation for vegetables. Frozen vegetables and potatoes form a significant proportion of the market in terms of frozen food consumption. The quality of frozen vegetables depends on the quality of fresh products, since freezing does not improve product quality. Pre-process handling, from the time vegetables are picked until ready to eat, is the important factor affecting quality of finished product. The process variables for freezing of different vegetables and flow chart are shown in Table 54.1 and Fig 54.1. Generally fruits after preliminary treatments are packed in sugar syrup and frozen in freezer.

52.1. Aim

To conduct practical on freezing of fruits.

52.2. Theory

Freezing is a method of preservation in which the food temperature is reduced below freezing point and a proportion of water changes in to ice-crystals. Immobilization of water to ice and the resulting concentration of dissolved solutes in unfrozen water cause lowering of water activity in the food. Thus, reduction in water activity and use of low temperature coupled with some pre-treatments is the basis for food preservation by freezing. The method for freezing of fruits depends upon the intended use. The process variables for freezing of different fruits and flow chart are shown in Table 52.1 and Fig 52.1. Generally fruits after preliminary treatments are packed in sugar syrup and frozen in freezer. The fruits are frozen to an internal temperature of -18oC or lower and kept at 18oC or lower throughout transport and storage.

51.1. Aim

To prepare products from tomato fruits.

51.2. Theory

Commercial products from tomatoes include ketchup, soup, cocktail, chutney, canned and dehydrated tomatoes. Processing of tomato is now practiced from home scale level to a large scale enterprise. Both puree and paste are used for preparation of different finished products like ketchup, canned and dehydrated products, soup etc. The method for preparation of these products are well standardized, however, some modification with respect to recipes are made in the processing plants owing to variation in the quality of the raw material. The method for preparation and recipe of different tomato products are as under:

51.3. Raw material, ingredients and utensils required

1. Tomatoes, sugar, salt, sodium benzoate etc.

2. Stainless steel knives, utensils, juicer, pulper, glass bottles, corking machine, crown corks, muslin cloth, boiler/gas bhatti, etc.

50.1. Aim

To prepare products from tomato fruits.

50.2. Theory

Commercial products from tomatoes include juice, puree and paste. Processing of tomato is now practiced from home scale level to a large scale enterprise. As a semi finished product, tomato puree is prepared on a small scale while at large scale tomato paste has gained commercial significance. Both puree and paste are used for preparation of different finished products like ketchup, juice, soup etc. The method for preparation of these products are well standardized, however, some modification with respect to recipes are made in the processing plants owing to variation in the quality of the raw material. The method for preparation and recipe of different tomato products are as under:

50.3. Raw material, ingredients and utensils required

1. Tomatoes.

2. Stainless steel knives, utensils, juicer, pulper, glass bottles, corking machine, crown corks, muslin cloth, boiler/gas bhatti, etc.

49.1. Aim

To perform practical on drying/dehydration of different vegetables.

49.2. Theory

Drying refers to the method of removal of moisture content from the food to a level at which the activities of food spoilage and food poisoning micro-organism are inhibited. Therefore, reduction in water activity of the food is the main principal of preservation by drying. In the dehydrator initial temperature is generally kept at 43oC which is then gradually increased to 60-66oC for vegetables. The product shall be prepared from wholesome vegetables free from blight, insect infestation and fungal discoloration. Only edible portion of the vegetables shall be used and it shall be free from stalks, peels, stems, and extraneous matter. The dried/dehydrated vegetable may contain permitted preservative. The finished product shall be of good edible quality and shall reasonably reconstitute to its original shape and quality on boiling for 15 minutes to an hour. The finished product shall be free from visible mould, insect or larvae. Kind of dry vegetable shall be declared on the label. Acid insoluble ash shall not be more than 0.5%.

48.1. Aim

To conduct practical on drying of fruits

48.2. Theory

Drying generally refers to the method of removal of moisture from the food under natural condition such as sunlight and wind for example open sun drying, shade drying etc. Dehydration refers to a process of removal of moisture by application of artificial heat under controlled conditions of temperatures humidity and air flow. It also represents drying of agricultural commodity to dry state. For drying, single thin layer of fruit and vegetables, either whole or sliced after primary pre-treatments is spread on the trays which are then placed inside the dehydrator or in the open sun for drying. In the dehydrator initial temperature is generally kept at 43oC which is then gradually increased to 66-71oC for fruits.