eChapters

Introduction

Chemicals that kill or retard fungi are fungicides. Most chemicals used to control plant diseases are ”protectants“ and must be applied before infection to protect the plant from invasion by a pathogen. Protectant fungicides are usually effective against a broad range of fungi and protect the plant against infection on the surfaces of the plant to which they are applied. Often, they require multiple applications during the growing season to maintain coverage as new growth emerges and weathering removes past coverage. A few chemicals are termed ”eradicants“ since they can eliminate an established infection. Some newer fungicides are systemic, meaning that they are absorbed by the foliage or roots and move within the plant to the site of infection. Systemic chemicals may be protectants, eradicants, or both systemic fungicides can be absorbed by the plant without harming it, and transported to other tissues where they are toxic to fungi. These compounds can control and eradicate established infections, but they are also vulnerable to fungi developing resistance, as they generally only target one step in a biosynthetic pathway to kill the fungus. To minimize the development of resistance by chemical overuse, fungicides are classified into groups based on their chemical activity.

Protected agriculture encompasses a range of structures, technologies, and tools designed to create a controlled microenvironment that enables optimal use of light, air, water, and nutrients, ultimately aiming to maximize yield per unit area while enhancing crop quality. Different types of protected structures are selected based on crop requirements and regional climatic conditions. These commonly include low tunnels, walk-in tunnels, net houses, greenhouses, shade net houses, polyhouses, and insect-proof net houses. Beyond physical structures, protected cultivation also incorporates technologies such as soil solarization, plastic mulching, use of specialized growing media, and container-based planting systems. These approaches collectively contribute to better water-use efficiency, higher productivity per unit of land and input, improved crop quality, and a reduction in pesticide usage through integrated pest and disease management strategies. By providing plants with a favorable and controlled growing environment through these techniques, protected agriculture promotes healthier growth, earlier flowering and fruiting, and helps crops realize their full yield potential with enhanced marketable quality.
CLASSIFICATION OF PROTECTIVE STRUCTURES
A protective structure is any built system intended to alter the growing environment for plants. Common examples include greenhouses, shade houses, and tunnels, which are widely used across the globe to cultivate high-quality fruits and vegetables. These structures improve crop yield and quality by influencing key environmental factors such as light, temperature, humidity, wind, and pest presence. The effectiveness of this environmental control depends on the type of materials used for the roofs and walls, along with the structure’s height, shape, and orientation. Conversely, in tropical and subtropical climates, greenhouses and screen houses are often covered with flexible plastic films—either solid or perforated—that help minimize heat buildup and support passive ventilation.

Objectives

• Better understand the various types of gene interaction.

Introduction

Gene interaction is the phenomenon of two or more genes that affect each other’s expression in different ways in the development of a single character of an organism. It is the modification of normal phenotypic expression of gene due to interaction between alleles or non-alleles. In such situation, two or more than two genes may interact to give rise to a particular phenotype

Soil conservation structures are physical or biological interventions designed to prevent soil erosion and degradation. These can range from basic, non-cultivated strips of land to advanced, engineered systems. Their primary role is to safeguard soil health, reduce surface runoff, and support the sustainability of agriculture over the long term.
Soil conservation as a broader practice involves adopting effective land management techniques to preserve soil quality, fertility, and productivity. It plays a vital role in sustaining crop yields, protecting natural ecosystems, and upholding overall environmental integrity.
Soil is fundamental to life on Earth, serving as the basis for agriculture, supporting biodiversity, and playing a key role in climate regulation. Despite its importance, soil faces growing threats from erosion and degradation, demanding urgent and focused action.
This section explores the critical role of soil conservation, outlines various strategies to maintain soil health, and examines the obstacles encountered in implementing these practices effectively. Understanding the significance of preserving soil is essential— not only for farmers but for the sustainability of the entire planet.
SOIL CONSERVATION
Soil conservation refers to the implementation of practices aimed at preventing soil degradation while preserving its fertility and productivity. It encompasses a variety of methods designed to minimize erosion, prevent nutrient depletion, and maintain soil integrity. The central aim is to keep soil fertile for agriculture and to support broader environmental functions, such as ecosystem balance and water regulation.

Objectives

• Better understand the dihybrid cross.
• Calculation of dihybrid phenotypic, genotypic and testcross ratios.

Principle

A cross is made between two true-breeding parents differing in two pairs of genes, producing an F₁ generation. These plants are inter-crossed to produce an F₂ generation. Mendel second law i.e., Law of independent assortment can be explained by studying the inheritance of two characters at a time, simultaneously. When two phenotypically distinct parents differing with respect to two characters governed by two pair of genes are crossed together. Each pair of genes assorts independently into all possible combination forming four kinds of progeny, two of these are parental type and two are recombinant types.

A drop inlet spillway is a hydraulic structure designed for soil and water conservation, particularly effective in areas with significant elevation changes such as gullies and ravines. It safely conveys excess water from reservoirs, embankments, or other structures to downstream channels, thereby preventing overtopping, erosion, and structural damage. The spillway consists of three main components: an inlet, a vertical conduit, and an outlet. Water enters through the inlet, drops vertically through the conduit, and then flows horizontally into a downstream channel via an outlet. This design is especially suitable for controlling gully heads and stabilizing gully beds. Typically, drop inlet spillways are constructed at fixed intervals across the gully width to form a series of control points. These structures help to dissipate flow energy, reduce erosion, and promote sediment deposition, gradually filling the gully section. Although effective, their use is generally limited to vertical drops of up to 3 meters. Drop inlet spillways play a crucial role in reducing land degradation and enhancing water management in erosion-prone areas.
COMPONENTS OF A DROP INLET SPILLWAY
A drop inlet spillway is composed of several key components that work together to safely and efficiently convey excess water while minimizing erosion and structural damage. The primary components include:
• Inlet Structure: This is the entry point where water enters the spillway. It can have various configurations, including circular or rectangular box-type flat crests or the more commonly known funnel-shaped morning glory crest.
• Vertical Shaft: A central conduit that allows water to drop vertically from the inlet down to the outlet level, utilizing gravitational force to convey flow.
• Outlet Conduit: A horizontal or inclined pipe or tunnel that transports water from the base of the vertical shaft to the downstream channe

A drop spillway is a type of structure used to release extra water from a dam or reservoir. It is characterized by a steep or nearly vertical drop in the water channel, which allows excess water to be discharged safely while reducing its energy. The main components of a drop spillway include a crest or weir at the top, a drop section for the falling water, and a downstream channel equipped with energy dissipation features to control erosion. The suitability of a site for a drop spillway depends on factors such as the terrain, soil stability, and flow conditions.
A spillway in general is designed to release surplus water from a reservoir once it reaches its storage limit. Water usually flows over the spillway during flood situations, when the inflow exceeds the dam’s capacity. Typically located at the top of the reservoir, a sphelps prevent water from overtopping the dam. In addition to spillways, some dams have bottom outlets controlled by gates or valves to release water. In cases where there is no overflow spillway, dams may rely entirely on these bottom outlets for flood control.
DEFINITION OF SPILLWAYS
A spillway is a structure that enables the controlled release of water from a dam or levee to flow downstream, usually into the original riverbed. Before examining its different types, it’s essential to understand why a spillway is necessary for dams.
A spillway acts as a channel to safely discharge surplus floodwater once a reservoir reaches its full capacity. Every dam is equipped with a spillway as a critical safety feature. Spillways can be integrated within the dam itself, positioned at its edge, or constructed as separate entities. It is essential that the spillway has adequate capacity; an undersized spillway could cause the dam to overflow, potentially leading to severe damage or complete failure of the dam.

Aim

To draw the drying characteristic curve for given grain by thin layer drying.

To determine the drying constant, heat utilization factor and coefficient of performance.

Theory

Fluidized bed drying is a method of drying by keeping the material in fluidized/ floating condition inside a chamber by hot air. In this drying process higher rate of moisture migration takes place.

F TEST (VARIANCE RATIO TEST)

F distribution is applied in several tests of significance relating to the equality of two sampling variances drawn on the basis of independent samples from a normal population.

Objectives

• Differentiate between fixatives and stains.
• Describe methods of staining.
• List the commonly used fixatives and stains and their composition.
• Describe the uses of above mentioned solutions and stains.

Introduction

Every time a part of an organism is removed, the action of bacteria will soon disintegrate, dry or putrefy it. They must be kept as close to normal as possible or in other words preserved and fixed in order to study these. Chemicals are required in many practical of Biology. Some of these chemicals preserve and specifically colour certain cell parts while others are used as solutions. You will learn about certain fixatives (preservatives) and stains in this chapter.

Glazing materials are commonly used to create transparent or translucent surfaces in architectural elements like windows and walls. Popular glazing materials include glass, acrylic, and polycarbonate, each offering distinct characteristics and uses. Glass, especially tempered or laminated varieties, provides strength, durability, and safety. Plastics like acrylic and polycarbonate, on the other hand, are lightweight and durable alternatives. The choice of glazing material depends on various factors, such as the desired level of transparency, required strength, thermal performance, and aesthetic preferences. In agricultural structures like greenhouses, glazing materials play a crucial
role in regulating light and temperature. Common options include glass, rigid plastics such as polycarbonate, acrylic, and fiberglass, as well as plastic films like polyethylene. Each material comes with its own advantages, including light transmission, impact resistance, durability, and cost, which influence its suitability for specific applications and climates.
Three critical properties of materials, coatings, and constructions used in windows, skylights, translucent panels, or other products that allow sunlight into a building are:
1. Thermal conductance (U-value)
2. Solar Heat Gain Coefficient (SHGC)
3. Visible Light Transmittance (VT)
The appropriate values for these properties depend on the climate, size, and positioning of the aperture. It’s common for a building to use multiple types of glazing, with different options for various sides and heights.

Greenhouse selection

Selection of greenhouse to be constructed is important as each type has its own merits and demerits. There are two common types of commercial greenhouses namely; (i) Freestanding (single span) and (ii) Ridge and furrow (gutter connected or multi-span). Multi-span structure permits economy in construction, heating and cooling but the single span gives flexibility as far as microclimate inside the greenhouse in concerned. The freestanding Quonset type is usually accommodates many growing situations but there height restrictions near the side walls. Another freestanding type is single gable greenhouse and its many variations. The ridge and furrow or gutter connected greenhouse are joined at the eave by a common gutter.

Introduction
A) Cultivation of Fungi
A fungus is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from the other eukaryotic life kingdoms of plants and animals. A characteristic that places fungi in a different kingdom from plants, bacteria, and some protests is chitin in their cell walls. Similar to animals, fungi are heterotrophy; they acquire their food by absorbing dissolved molecules, typically by secreting digestive enzymes into their environment. Fungi do not photosynthesize. Growth is their means of mobility, except for spores (a few of which are flagellated), which may travel through the air or water. Fungi are the principal decomposers in ecological systems. These and other differences place fungi in a single group of related organisms, named the Eumycota (true fungi or Eumycetes), which share a common ancestor (form a monophyleticgroup), an interpretation that is also strongly supported by molecular phylogenetics. This fungal group is distinct from the structurally similar myxomycetes (slime molds) and oomycetes (water molds). The discipline of biology devoted to the study of fungi is known as mycology. In the past, mycology was regarded as a branch of botany, although now known fungi are genetically more closely related to animals than to plants.

Introduction

Musa species and cultivars are identified mainly on the basis of morphological characters. Somatic mutations and changes brought about by environment are major obstacles to the accurate identification of clones (Kaemmer et al., 1992). Isoenzymatic markers provide an additional tool for the characterization of germplasm and have been successfully employed in banana to provide better understanding of somaclonal variants and to detect genetic differences at clonal level.

Being located within the center of diversity of cultivated banana, the South Indian state of Kerala accounts for a large share of variability, especially the AA, AB, AAB and ABB genomic groups.Nendran, the French plantain cultivar indigenous to Kerala (Jacob, 1952) is represented by many ecotypes/clones. Other prominent cultivar groups include Mysore (AAB), Rasthali (AAB), Neypoovan (AB), Kunnan (AB), Monthan (ABB) and Karpooravalli (ABB). The variability has been collected and conserved in the field at the Banana Research Station, Kannara. These have been characterized morphologically employing per INIBAP/IPGRI Musa descriptors, facilitating the identification of distinct cultivars, clones and synonyms.This project was initiated to survey the isozyme polymorphism in the cultivar groups and to select suitable system for clonal identification.Results of the study employing three enzymatic systems -esterase, diaphorase and peroxidase are presented

The study of agri-enterprises in the service sectors, particularly through the lens of value chain models, is crucial for understanding how agricultural products are transformed from raw materials into value-added goods and services. This involves analyzing the entire process of production, processing, distribution, and retailing, as well as the supporting services that enhance efficiency and effectiveness in these processes.
Key Components of Value Chains in Agri-Enterprises
1. Input Supply
º Description: This segment includes all the services and products required to support agricultural production, such as seeds, fertilizers, machinery, and farming services (e.g., land preparation).
º Service Providers: Agricultural suppliers, cooperatives, and input distribution companies.
2. Production
º Description: The actual farming activities where crops are grown or livestock is reared. This stage can incorporate various services such as extension services, training, and digital solutions for precision
agriculture.
º Key Considerations: Sustainable practices, labor management, and crop yield optimization.

KURTOSIS

Kurtosis refers to the extent to which unimodal frequency curve is peaked. Kurtosis is a measure that refers to the peakedness of the top of the curve. Kurtosis gives the degree of flatness in the region about the mode of a frequency distribution.

Types of Kurtosis

There are three categories of kurtosis that can be displayed by a set of data. All measures of kurtosis are compared against a standard normal distribution, or bell curve.

The first category of kurtosis is a mesokurtic distribution. This type of kurtosis is the most similar to a standard normal distribution in that it also resembles a bell curve. However, a graph that is mesokurtic has fatter tails than a standard normal distribution and has a slightly lower peak. This type of kurtosis is considered normally distributed but is not a standard normal distribution.

The second category is a leptokurtic distribution. Any distribution that is leptokurtic displays greater kurtosis than a mesokurtic distribution. Characteristic of this type of distribution is one with extremely thick tails and a very thin and tall peak. The prefix of “lepto-” means “skinny,” making the shape of a leptokurtic distribution easier to remember. T-distributions are leptokurtic.

The final type of distribution is a platykurtic distribution. These types of distributions have slender tails and a peak that’s smaller than a mesokurtic distribution. The prefix of “platy-” means “broad,” and it is meant to describe a short and broad-looking peak. Uniform distributions are platykurtic.

COEFFICIENT OF THE MEAN DEVIATION

A relative measure of dispersion based on the mean deviation is called the coefficient of the mean deviation or the coefficient of dispersion. It is defined as the ratio of the mean deviation to the average used in the calculation of the mean deviation.

MEAN DEVIATION

The mean deviation is the first measure of dispersion that we will use that ac- tually uses each data value in its computation. It is the mean of the distances between each value and the mean. It gives us an idea of how spread out from the center the set of values is.

The mean deviation is based on all the observations, a property which is not possessed by the range and the quartile deviation. The formula of the mean de- viation gives a mathematical impression that is a better way of measuring the variation in the data. Any suitable average among the mean, median or mode can be used in its calculation but the value of the mean deviation is minimum if the deviations are taken from the median.

Objective: The distribution of age of males at the time of marriage was as follows

Measures of Central Tendency

The term ‘Mean” or ‘average’ is something, we have been familiar with from a very early age when we start analyzing our marks on report card. We add together all of our test results and then divide it by the sum of the total number of marks there are. We often call it the average. However, statistically it’s the Mean!

The Median is the ‘middle value’. When the totals of the list are odd, the me- dian is the middle entry in the list after sorting the list into increasing order. When the totals of the list are even, the median is equal to the sum of the two middle (after sorting the list into increasing order) numbers divided by two. Thus, remember to line up values, the middle number is the median!

The Mode in a list of numbers refers to the list of numbers that occur most frequently. A trick to remember this one is to remember that mode starts with the same first two letters that most does. Most frequently - Mode.

Objectives

• Find out the number and types of gametes and gametic recombination in monohybrid, dihybrid and trihybrid crosses.

Principle

Gametes are reproductive cells that join together to form a new cell called a zygote during sexual reproduction. Pollen in seed-bearing plants, is the gametophyte producing male gamete. Female gametes (ovules) are included in the ovary of plant. At maturity a sexually reproducing individuals forms the gametes. Homozygote generate only one form of gamete. Homozygous referring to a diploid cell or organism possessing two identical alleles of a specific gene (e.g. AA or aa). Heterozygote generate different types of gametes. Heterozygous referring to a diploid cell or organism possessing two different alleles of a specific gene (e.g. Aa).

Introduction

A microscope is an optical instrument consisting of a lens or a combination of lenses for making magnified images of minute objects. A simple microscope consists of a single lens of magnified glass held in a frame, usually adjustable and has a stand for holding the object and a mirror for reflecting the light. But a compound microscope consists of two lenses i.e., objective and eye piece respectively. A compound microscope gives much greater magnification than simple microscope. The compound microscope will be extensively used in this course in studying various morphological and staining characters of soil microorganisms.

MOMENTS

The term moment in mechanics refers to the measure of a force with reference to its tendency to produce rotation. The strength of this tendency is depen- dent upon the amount of the force and the distance from the origin at which the force is applied. If on both the sides of the origin the force are equal than there will be a balance, at a balanced position the positive product equals the negative product.

Moment is used in Statistics in a quite analogous sense. The class frequencies are looked upon as the forces and the deviations of the different values from the mean are taken as the distances. In other words, moment is the mean of the first, second, third, fourth, etc. powers of deviations of the different values from the arithmetic mean. The first moment about the mean is always zero and second moment about the mean is variance.

If the moment calculated from arithmetic mean are called central moments and denoted by μ with a subscript which indicate the order of the moment. Moments are the mean values of powers of the deviations in any frequency distribution taken about three points

Objectives

• Better understand the monohybrid cross.
• Calculation of monohybrid phenotypic, genotypic and testcross ratios.

Principle

Monohybrid cross deals with the study of inheritance of one pair of contrasting characters. The alleles of contrasting character selected in the monohybrid cross will show exact dominance and recessive relationship. It is also defined as a cross is made between two true-breeding parents differing for a single trait, producing an F₁ generation. These plants are intercrossed to produce an F₂ generation. Monohybrid crosses study led to the Mendel’s law of segregation. Monohybrid cross was first produced in pea by Mendel to explain the “law of segregation”. When parents with distinct phenotypes are crossed, in F₁ generation, only one type of plants appears phenotypically. However, segregation can be observed in F₂ progeny and the population can be divided into two phenotypes classes. After counting the individuals. It is observed that 75% of them express the dominant phenotype and 25% of them express recessive phenotype.

Our exposure to wide variety of chemicals has increased markedly in the recent past. Most of these compounds are mutagenic as well as potential carcinogens. Emphasis is being laid to develop method for detection of environmental carcinogens so that their use can be avoided.

Despite the fact that mammalian cell structure and human enzymatic pathways differ from those in bacteria, the chemical nature of DNA is common to all organisms; this permits the use of bacterial test systems for rapid detection of possible mutagens.

The Ames test which was developed by Bruce Ames in 1970, at the University of California, U.S.A. is a mutational reversion assay employing several special strains of Salmonella typhimurium, each of which has a different mutation in the amino acid histidine biosynthesis operon.

S. typhimurium, the indicator organism, used in this test is the mutant strain that cannot synthesize histidine (His^-), lack the enzyme to repair DNA so that mutation shows up readily and has leaky cell wall that permit the rapid entry of chemicals. In addition, this S. typhimurium strain carries mutation enhanced plasmid, the combined effect of these characters increase the sensitivity of the organism to mutagenic treatments.

ANALYSIS OF VARIANCE

Analysis of Variance (ANOVA) is a hypothesis-testing technique used to test the equality of two or more population (or treatment) means by examining the variances of samples that are taken. ANOVA allows one to determine whether the differences between the samples are simply due to random error (sampling errors) or whether there are systematic treatment effects that cause the mean in one group to differ from the mean in another.

Most of the time ANOVA is used to compare the equality of three or more means, however when the means from two samples are compared using ANOVA it is equivalent to using a t-test to compare the means of independent samples.

ANOVA is based on comparing the variance (or variation) between the data samples to variation within each particular sample. If the between variation is much larger than the within variation, the means of different samples will not be equal. If the between and within variations are approximately the same size, then there will be no significant difference between sample means.

These materials include barrier coated paper bags, barrier laminated film bags, jute bags, PP woven box bag and cotton bags.
 
A: Paper Bags
    1.    Coated paper:  bags provide a barrier for leaking or staining of the product. This can be done by a greaseproof or claycoated kraftpaper.
    2.    Open-Mouth sacks:  can be manufactured using different types of paper. Simple kraftliner, glossy claycoated and lacquered outerliner are possible. These sacks can be supplied with liners and printed up to 8 colours.

PPEs are the personal protection equipments which protect the personnel against some hazards in the shop floor. PPEs form important aspects of Environment (safe disposal of treated chemicals, dusts coming out of processing), Safety (to seed storages) and Health (personnel) (ESH) strategy of any shop floor.

ABSTRACT

A satellite based earth observation system enhances our understanding of the entire earth as an integrated system. Remotely sensed data gives accuracy and complete data. To study the coastal zone or area remote sensing is on of the best technology to monitor the regular changes over the time. Here satellite data used to understand the distribution of prawn farms along the Nagappattinam coast. It has stretched from River Coleroon in the north to Point Calimer in south. Nagappattinam coast rocked by tsunami in 2004 and it damaged the whole life of coastal and fishing people. This paper has attempted to analyse the distribution of prawn farms and impact of tsunami in the Nagappattinam coast using remote sensing.

1. INTRODUCTION

Nagappattinam coast is located on the eastern part of Nagappattinam. It is a unique immemorial for its agricultural activities and lying in the deltaic region of Cauvery River. Nagappattinam coast (Fig 1) is peninsular delta area bounded by Bay of Bengal on the east, Palk Strait on the south, and Thiruvarur and Thanjavur districts on the west and Cuddalore on the north. The study area is located between 10^o 10’ N to 11^o 50’ N latitudes and 79^o 45’ E to 80^o 00’ E longitudes. Nagappattinam coast has covered an area of 935 sq. km.

I. Crop-Based Livelihood Models
• Description: Focuses primarily on cultivating and selling crops.
• Production Analysis:
º Crop Selection
• Identify the specific crops grown (e.g., rice, wheat, maize, vegetables, fruits).
• Analyse the rationale behind crop selection (market demand, suitability to local climate and soil, tradition, etc.).
• Assess the use of crop rotation, intercropping, and cover cropping practices.
º Agronomic Practices
• Evaluate the efficiency and effectiveness of tillage, planting, irrigation, fertilization, and pest/disease management practices.
• Determine the level of mechanization used in crop production.
• Investigate the use of integrated pest management (IPM) and sustainable agricultural practices.
º Yield
• Measure crop yield (e.g., tons per hectare, bushels per acre).
• Compare yields to regional and national averages.
• Identify factors that limit yield (e.g., water stress, nutrient deficiencies, and pest /disease outbreaks).

Abstract

Prolactin is a hormone secreted predominantly from anterior pituitary and imparts important roles related to development of mammary gland, reproductive behaviour and immune response. The objective of this study was to explore restriction fragment length polymorphism (RFLP) pattern of prolactin gene, to estimate gene and genotype frequencies of different restriction fragments and to study the effect of genotypes on milk production and reproduction traits in crossbred cattle Bos taurus x Bos indicus (Jersey x HF x Sahiwal).The present study investigated RFLP within 156bp amplification products of the bovine prolactin gene exon 3 in 30 crossbred cattles selected randomly from a herd using specific set of primers (Forward primer- 5’- CGA GTC CTT ATG AGC TTG ATT CTT -3’ and reverse primer- 5’- GCC TTC CAG AAG TCG TTT GTT TTC -3’). Restriction enzyme digestion with RsaI revealed three patterns in crossbred cattle, one having 156bp fragment (AA genotype), second having 156bp, 82bp and 74bp fragments (AB genotype) and third having 82bp and 74bp fragments (BB genotype) indicating genetic polymorphism. The gene and genotype frequencies in crossbred cattle were found to be 0.78 and 0.22 for A and B alleles and 0.70, 0.17 and 0.13 for AA, AB and BB genotypes, respectively.

A relative measure of dispersion based on the quartile deviation is called the coefficient of quartile deviation. It is defined as

Paratition Value

Median is calculated for dividing the series into two equal parts. If the series is divided into four, eight, ten or hundred parts then the measures are called Quartile, Octile, Decile and Percentile respectively denoted by Q_(1,2,3), O_(1,2..7), D_(1,2…9) and P_(1,2…99).

12.1 Introduction
Mulberry silkworm is a domesticated insect which cannot live without sufficient human care. It is also sensitive to high temperature and relative humidity. Besides good feed, a temperature range of 23°C to 28°C and relative
humidity of 75-80% is ideal for silkworm. Though, there are a number of modern gadgets to regulate the temperature and relative humidity, investment on them is uneconomical. Therefore, mulberry sericulture is practiced only
in those areas where the climate is congenial and the crops schedule is so regulated to avoid seasons with extreme climate. Besides, the silkworm rearing house is constructed to provide sufficient ventilation and keep the ambiance sufficiently cool. Due to poverty, many farmers rear silkworms within their dwelling house which cannot be disinfected due to the pungent nature of the chemicals used. However, it will be ideal to have a separate rearing house or at least a separate room for rearing purpose. The present unit deals with different kinds of rearing houses required for silkworm rearing.

20.1 Introduction
The technique of reeling several cocoon baves together to create a single thread is known as silk reeling. This is accomplished by winding the resulting thread onto a rapidly spinning reel after collectively unwinding filaments from a collection of cooked cocoons at one end in a heated water bath. There are three different ways to reel in raw silk: (1) directly on a standard-sized reel, (2) indirectly on small reels, and (3) by using a re-reeling machine to transfer the reeled silk from small reels onto standard-sized reels. An efficient reeler willhold onto the predefined number of cocoons per end in order to produce silk with a consistent denier Some techniques are used in reeling. Different reeling mechanisms are used for different purposes.
20.2 Various Silk Reeling Devices
20.2.1 Hand Spinning Wheel
Using a simple spinning method, two hands run the apparatus to remove silk thread from cocoons: one hand turns the wheel while the other feeds the cocoons. In one of the devices, the cocoons are cooked, while in the other, reeling thread is wound onto each wheel. A more tactile and artisanal method of silk reeling is available with hand spinning wheel reeling. A great degree of expertise and experience are needed to provide consistent outcomes and the appropriate silk characteristics (Fig.20.1).

Freezing is among the oldest and most commonly used techniques for preserving food, as it effectively maintains taste, texture, and nutritional value better than other preservation methods. This process leverages the advantages of low temperatures, which inhibit microbial growth, slow down chemical reactions, and delay cellular metabolic activities.
ROLE OF REFRIGERATION SYSTEMS FOR FRUITS AND
VEGETABLES
Proper collection, handling, storage, and distribution of fruits and vegetables are crucial to ensuring they reach consumers in the best possible condition. Refrigeration plays a key role in maintaining freshness and extending the shelf life of these products. Companies involved in production, processing, and marketing that implement efficient commercial and industrial refrigeration systems benefit in several ways:
• Slowing down the ripening and aging of tissue cells.
• Preventing microbial growth.
• Reducing overall quantitative and qualitative losses.

REGRESSION

Regression means to revert or return back. The term was first introduced by Sir Francis Galton in1877. Regression technique is applicable in all those fields where two or more relative variables have the tendency to go back to the mean. Regression analysis refers to the methods by which estimates are made of the values of a variable from the knowledge of the values of one or more other variables and to the measurement of the errors involved in this estimation pro- cess.

In statistical modeling, regression analysis is a statistical process for estimat- ing the relationships among variables. It includes many techniques for mod- eling and analyzing several variables, when the focus is on the relationship between a dependent variable and one or more independent variables. Regres- sion analysis helps one understand how the typical value of the dependent variable (or ‘criterion variable’) changes when any one of the independent variables is varied, while the other independent variables are held fixed. Most commonly, regression analysis estimates the conditional expectation of the dependent variable given the independent variables – that is, the average value of the dependent variable when the independent variables are fixed.

In fishes the outermost covering of the body is called as exoskeleton. The exoskeleton is covered by the covering called as skin. In most of the fishes the skin is covered with an exoskeleton in the form of scales, but a few fishes are naked having no scales on the body and body is covered only by thick skin as like the catfishes. While some other fishes like the polyodan and the Acipenser exhibit an intermediate condition, having scales or scale like plates only at same localized regions of the body. The scales of fishes are products of the activity of the skin. The scales of fishes have become modified in various ways mainly to provide protection.

The scales are useful for the classification and identification of fishes (in fish Taxonomy it is used) Fish scales are self for the determination of age of the fish. Scales are also useful for the estimation of the number of the spawning.

Scale provide important information about extinct fishes and useful in identifying food habits of piscivorous animals. Scales are important exoskeleton in fishes According to the mode of origin there are two types of scales i.e. 1) Placoid and 2) Non- placoid scales.

Rubber-roll Sheller consists of two rubber rolls rotating in opposite direction at different speeds. One of the roll is fixed while the other is adjustable to obtain desired clearance between them. The rolls are driven by mechanically. The adjustable roll normally runs about 25% slower than the fixed one. A feeder feeds paddy uniformly to the machine (Fig.27.1). Paddy is fed in thin layer through the clearance between two rubber rolls, rotating in opposite directions at different speed. Difference in speeds of the rolls develops a shearing force on grain surface results in the splitting, breaking and separating the husk from the grains. One part of the husk is subjected to shearing forces whereas the other part in contact with the slower roll is under compression and is thus subjected to breaking forces. Husking is done by the action of these forces. The clearance between them should be smaller than the mean thickness of paddy and may be adjusted subsequently by judging the shelling efficiency. If the gap between rolls is properly adjusted, it can shell up to 95% of paddy fed to it. At decreased gap excess pressure results more breakage of grain and can also cause coloring of shelled rice. During shelling the faster roll should have a peripheral speed of 10 -13 m/ s, while the slower roll 8-10 m/s.

TEST OF SIGNIFICANCE FOR CORRELATION COEFFICIENT

Coefficient of correlation is a numeric characteristic of a population and is estimated from a sample of the bi-variate population. If ρ be the coefficient of correlation in the population and r be its sample estimate based on n pairs of observations, then standard error of r is given

9.1 Structure of Silk Gland
The silk of silkworms is secreted by a pair of labial glands, known as silk glands. The silk glands lie ventral to the alimentary canal. In full grown larvae, these occupy most of the body cavity. The silk glands are tubular in shape with different diameters in different regions. Each gland has 3 distinct regions (Fig.9.1).
(1) Posterior Region: Blunt, highly folded tubular posterior regions of both glands remain attached to tracheal bushes of silkworm. This part secretes fibroin as fibrinogen which converted to fibroin upon extrusion.
(2) Middle Region: Most prominent and widest part of silk gland. It remains folded in a W-shaped structure and thus has 3 limbs posterior, middle and anterior limbs. The posterior arm secretes sericin-I. It gets
surrounded by sericin-II secreted from the middle limb. This sericin again gets surrounded by sericin- III secreted from the anterior limb. The middle region of silk gland also acts as the reservoir of fibroin where the
later gets mature during the storage period.
(3) Anterior Region: The thin anterior region of silk gland has no secretory role and only transports the assembled silk to the spinneret.

Objectives

• To study working principles of simple microscope
• Study different parts of simple microscope

Introduction

This is the first ever microscope. It was founded by Leeuwenhoek in 17^th century. He combined a convex lens with a specimen holder, for seeing the magnified images of small objects. It looks like a magnifying glass because it has the capacity to magnify between 200 and 300 times. A simple microscope is a small focal lens used to view the magnified images of small objects. It is just like a hand lens and glass with relatively lower magnification power.

SKEWNESS

Skewness means lack of symmetry. Skewness denotes the tendency of a distri- bution to depart from symmetry. A frequency distribution is said to be skewed if the frequencies decrease with markedly greater rapidity on one side of the central maximum than on the other side. This characteristic of a frequency distribution is known as skewness and the measures of asymmetry are usually called measures of skewness.

The main object of measuring skewness is to know the direction of the varia- tion from an average and to compare the frequency distribution and the shape of their curves.

There are two types of skewness

(i) Positive Skewness (ii) Negative Skewness

Some basic informations about genera of Family Pythiaceae, Peronosporaceae and Albuginaceae;

Pythiaceae

Indeterminate (grows continuously) sporangiophores, have sporangia that are borne variously, but not in chains, on somatic hyphae or on sporangiophores. This family includes the genera Pythium and Phytophthora.

Peronosporaceae

Determinate sporangiophores, form sporangia on well-defined, branched sporangiophores of determinate growth. There are seven genera in the family including Basidiophora, Bremia, Bremiella, Peronospora, Plasmopara, Pseudoperonospora and Sclerospora.

Albuginaceae

Club shaped sporangiophores, catenate sporangia, produces chains of sporangia on club-shaped sporangiophores of indeterminate growth. The Albuginaceae contains a single genus Albugo.

Abstract

Groundwater is one of the major sources of exploitation in arid and semi -arid regions of Rajasthan. To protect groundwater, its data on spatial distribution are important along with quantity. Analysis of quality of groundwater is also very important, because the physical and chemical characteristics of groundwater determine its suitability for agricultural, industrial and domestic usages. The importance ground water increases many fold for arid tracts like Western Rajasthan. Here quality of water is also matter of serious concern. Geostatistics methods are most advanced techniques for interpolation of Groundwater quality. The present study appraises the groundwater quality of western Rajasthan for agricultural purpose with GIS technology. Kriging Raster Interpolation technique of spatial analyst module in Arc GIS software has been used to generate the spatial distribution map of ground water for agricultural purpose. In western Rajasthan only 28% (58109 km2) of ground water falls under the category of good and is suitable for agricultural use. 

FOR GROUPED DATA

Objective: The following data shows the marks of students and their frequencies find the standard deviation and its coefficient.

STANDARD DEVIATION AND THEIR COEFFICIENT

The standard deviation is a measure of the spread of scores within a set of data. Usually, we are interested in the standard deviation of a population. However, as we are often presented with data from a sample only, we can estimate the population standard deviation from a sample standard deviation. These two standard deviations - sample and population standard deviations - are calculat- ed differently. In statistics, we are usually presented with having to calculate sample standard deviations.

STANDARD NORMAL DISTRIBUTION

If μ = 0 and σ = 1, the distribution is called the standard normal distribution or the unit normal distribution, and a random variable with that distribution is a standard normal deviate. The approximate test is given by

t TEST FOR PAIRED OBSERVATION

This test is used for testing whether two series of paired observations are gen- erated from the same population on the basis of the difference in their sample means.