eChapters

Biofertilizers can be defined as the preparations containing strains of micro-organisms which can augment the microbiological process viz. nitrogen fixation, phosphate solubilization or mineralization, excretion of plant growth promoting substances or cellulose or lignin biodegradation in soil, compost or other environments. Biofertilizers can be divided into nitrogen fixing bacteria, phosphate solubilizing and mobilizing microorganisms and organic matter decomposers as (Table 3.1 and Fig. 3.1):

On the basis of Nitrogen Fixation: On the basis of N₂ fixation, they are divided in to two sub categories as

1. True bone tumours. Neoplasms arising from cells of mesenchymal origin, derived from a common ancestry and whose function is primarily skeletal boen formation. These tumours fall into four main groups according to the predominant cell type present. By reason of the mutability of the cells metaplasia is common and intermediate stages are found.

Characters

1) They are called true flies.

2) It is one of the largest orders in the class Insecta, having more than 1, 20, 000 described species.

3) On thorax, there is only one pair of wing (Di = two; ptera = wings) i.e. Mesothoracic wing. Metathoracic pair of wings are modified into structures called “Halters or balancers.” Halter is a rod like structure having knob at distal end. During flight, this halter goes on vibrating @ 300 vibrations/sec. Its main function is to keep fly balanced during flying/flight.

4) One pair of compound eyes is present which is dichoptic in female and holoptic in male.

5) Larvae are apodous which is called maggots.

6) The order Diptera is divided into suborders, Orthorrhapha and Cyclorrhapha. These sub orders are distinguished morphologically by wing venation and structure of antennae.

Climatic classification is the method of identifying climatologically homogenous regions. The systematic study of climate and its analysis and processing, which is referred as climatology plays an important role in national weather, planning activities and decision making in human activities. Iso climatic regions are those regions which have same climatic conditions.

Specific objectives of climatic classification

To identify the climates for transfer of production technology developed at particular center.

To provide adequate indices of moisture availability for successful crop production in drylands.

To quantify the risk levels associated with production constrains to agriculture production.

Climate classification systems are ways of classifying the world’s climates. One purpose of climatic classification is to group together places with similar climatic characteristics. That means if an area or region is categorised under a particular climatic type, it possesses broadly uniform characteristics with respect to climate. Classifications have been based on climatic elements such as temperature and precipitation, which are measurable, and on differences in tree species, soil characteristics, topography, etc. The varied nature of earth’s surface and the many interactions that occur among atmospheric processes give every location on the earth a distinctive climate.

Although the delineation of distinct climates may seem likely a very straightforward job, establishing the criteria by which climates are delineated requires considerable subjectivity. There are many ways of classifying the climate depending on the user and the level of understanding of the climate system at a given time. Different regions of the same climate type constitute isoclimatic regions. Identification of isoclimates helps in the transfer of agro-technology and suggesting new cropping pattern. Climatic classification is based on two approaches, viz., generic or empirical approach and genetic approach. In the generic approach the classification is based on the observed climatic elements or their effects on the phenomena, usually vegetation or humankind. The genetic classification is based on climatic controls such as general circulation, net radiation and moisture fluxes.

The concept of climate classification was originally brought out to delineate natural vegetation, which is dependent on rainfall and temperature. Climate classification is unique tool to find out different climate types across the globe, out of which isoclimates or homoclimates can be traced out.

The climate of a particular place is the function of a number of factors such as latitude and its influence on solar radiation received, air mass influences, location of global high and low pressure zones, heat exchange from ocean currents, distribution of mountain barriers, pattern of prevailing winds, distribution of land and sea, and altitude.

The classification of crop diseases is a fundamental aspect of plant pathology, as it provides a framework for understanding the causes, symptoms, and management of diseases that affect crops. Classification is the process of grouping organisms or diseases into categories based on their shared characteristics, and it is essential for developing effective disease management strategies. Crop diseases can be classified in various ways, including by their causes, symptoms, hosts, and environmental factors. Understanding the classification of crop diseases is crucial for farmers, agricultural professionals, and researchers, as it enables them to identify diseases accurately, select appropriate management strategies, and develop new control methods. One of the primary ways to classify crop diseases is by their causes, which can be broadly categorized into infectious and non-infectious diseases. Infectious diseases are caused by living organisms, such as fungi, bacteria, viruses, and nematodes, while non-infectious diseases are caused by environmental factors, such as temperature, moisture, nutrient deficiencies and some substances toxic to plants. Another way to classify crop diseases is by their symptoms, which can include visible changes in plant growth, color, or texture, as well as reductions in yield or quality. Symptoms can be categorized into different types, such as leaf spots, blights, wilts, and tumors, each of which is associated with specific diseasecausing agents. Classification of crop diseases can also be based on the host plant, with diseases being grouped according to the specific crop or plant species they affect. This type of classification is useful for developing crop-specific disease management strategies. In this chapter, we will explore the different classification systems used for crop diseases, including their causes, symptoms, hosts, and environmental factors. We will also discuss the importance of accurate disease classification for effective disease management and the development of new control methods. The broad classification of crop diseases followed uniformly throughout the world is based on the nature of the causal agent, and it categorizes diseases into two main groups: infectious diseases and non-infectious diseases.
5.1 Infectious diseases
These are caused by living organisms, such as fungi, bacteria, viruses, and nematodes, which can spread from plant to plant. These diseases can be further subdivided into several categories, including:

The agricultural sector is a complex and dynamic system, influenced by a
multitude of factors, including weather, soil, and market conditions. To provide effective support to farmers, it is essential to have a comprehensive understanding of the diverse range of crops and farming systems that exist. Classification of crops and farmers is critical components of this understanding, as it enables the development of targeted and customized Agromet advisories that take into account the specific needs and circumstances of different farming communities.
9.1. The Importance of Classification
Classification of crops and farmers is a fundamental concept in agriculture, as it allows for the identification and grouping of similar crops and farming systems. This, in turn, enables the development of tailored recommendations and advisories that are relevant to specific farming contexts. By classifying crops and farmers, agricultural researchers, extension agents, and policymakers can better understand the diverse range of agricultural practices and systems, and develop targeted interventions that address the unique needs and challenges of different farming communities.
9.1.1. Customized Agromet Advisories
Agromet advisories are critical for supporting farmers in making informed decisions about their agricultural practices. By providing timely and accurate weather forecasts, advisories can help farmers to optimize their crop management, reduce losses due to weather-related events, and improve their overall productivity and income. However, to be effective, Agromet advisories must be customized to take into account the specific needs and circumstances of different farming communities. This requires a comprehensive understanding of the diverse range of crops and farming systems that exist, as well as the specific challenges and opportunities faced by different farmers.
9.1.2. The Role of Classification in Customized Agromet Advisories
Classification of crops and farmers plays a critical role in the development of customized Agromet advisories. By grouping similar crops and farming systems together, researchers and extension agents can identify patterns and trends that inform the development of targeted advisories. For example, advisories for farmers growing wheat in a particular region may focus on issues related to soil moisture, temperature, and pest management, while advisories for farmers growing rice in a

Crops: Is a cultivated plant that is grown on large scale commercially, especially cereal, pulses, fruits or vegetables.

Classification of crops : Several crop plants are alike with respect to ontogeny (Development), morphology, anatomy, physiology and requirement of environment. Classification is done to generalize similar crop plants as a class for attaining better understanding of them. Field crops are classified in several ways.

Textile and apparel defects are commonly classified according to their severity, effect on product performance and influence on visual appearance. Accurate classification supports inspection decisions, corrective action and cost management. Critical defects create safety hazards, breach legal or compliance requirements, or make a garment unusable; affected products must be rejected immediately. Major defects significantly reduce appearance, durability or functionality and ordinarily require correction before sale, although they may not endanger the wearer. Minor defects are small departures from specifications that do not substantially affect usability but may lower perceived quality. Consistent classification enables inspectors to apply AQL criteria objectively and communicate appropriate acceptance, rejection or rework decisions.

Plant diseases are caused by different etiological agents like Fungi, Bacteria, Viruses, Viroids, Phytoplasmas, Rickettsia like bacteria, Nematodes, Algae and Protozoan parasites. To control these specific pathogens and the diseases caused by them, a specific group of medicine/chemical molecule is required.

Droughts are intricate and multifaceted phenomena that can have far-reaching impacts on the environment, economy, and society. The complexity of droughts arises from the interplay of various factors, including climate variability, water availability, land use, and human activities. Given the varying characteristics and consequences of droughts, classification becomes a crucial step in understanding and managing these events. By categorizing droughts based on their severity, duration, and impact, researchers and policymakers can better grasp the intricacies of drought dynamics and develop targeted strategies for mitigation and adaptation. The classification of droughts is necessary for several reasons

Introduction

Drought occurs when a region experiences below average precipitation, resulting in prolonged shortages in its water supply, which can have a significant impact on agriculture and the ecosystem. To reduce the effect of drought on farm production and stabilize farm income, farmers must take systematic measures called drought coping mechanisms. These measures can be categorized into two broad categories: Ex-ante coping mechanisms, which are taken before the occurrence of drought, and Ex-post coping mechanisms, which are taken after the occurrence of drought. Ex-ante coping mechanisms include activities such as crop, spatial, and varietal diversification, income diversification, and the use of savings. Ex-post coping mechanisms include changing consumption patterns, borrowing money, liquidating assets, seeking government drought relief funds, and migration. Drought can have a significant impact on crop and livestock production, causing farmers to adopt drought coping mechanisms to stabilize their farm income. This study goals to identify the factors that determine the adoption of such coping mechanisms, to mitigate the effects of drought on the livelihoods of farmers.

Rural Economy and Agriculture

It is being progressively recognized that the globalized nature of economies across the world is affecting the economic security of all nations. Particularly, in this present era when globalization, liberalization and privatization are rapidly budding and creating new threats and opportunities, it is established that farmers need to be organized to participate and proliferate in the development processes. The phenomenon has triggered substantial debate as to whether globalization is positive evolution of economic action or detrimental to the interests of certain countries or specific groups (Kaplinsky, 2004; Nadvi, 2004).

Forages can be classified according to the nutrient density in the dry matter.
Roughages: These are diets that have more than 18% crude fiber, more than 35% cell wall content, and less than 60% TDN on DMB. There are two types of roughage: dry roughage and green roughage. Roughages are classified as succulent or non-succulent according on their moisture content. Succulent feeds are ones with greater than 80% moisture. Non-succulent feed contains less amount of moisture. Roughages can also be classified based on legumes, for example, leguminous and non-leguminous roughages. Roughages are divided into three types based on their nutritional content (on DMB): maintenance, productive and non-maintenance.
Roughages: Feedstuffs having more than 18% crude fibre, more than 35% cell wall contents and less than 60% TDN on dry matter basis (DMB) are known as roughages. There are two kinds of roughages, dry roughage and green roughage. On the basis of moisture content the roughages can be classified into succulent and non-succulent. Succulent feeds are those which contain more than 80% moisture. Feed contains lesser amount of moisture is known as non-succulent. Roughages can also be classified on the basis of legumes. e.g. leguminous and non-leguminous roughages.
Roughages can be classified based on their nutritive value (on DMB) into maintenance type, productive type and non-maintenance type.

A. Answer the following questions:

1.    What is concentrate ingredients?

Ans: These are feedstuffs having more than 60% TDN, less than 35% cell wall contents and less than 18% crude fibre on dry matter basis.

2.    What is soilage?

Ans: Pasture whether natural or cultivated when cut and fed green to an animal in its own stall is called soilage.

3.    What is husk?

Ans: Dry outer covering of grains and grams e.g. gram husk, rice husk.

4.    What is fodder?

Ans: Any green plant or crop meant for animal feeding for supply of nutrients and bulk.

5.    What is leguminous fodder?

Field Crops: Refers to the crops grown on a vast scale. They are classified in the following ways

1. According to the place of origin

2. Botanical classification

3. Commercial classification

4. Economic classification

5. Seasonal classification

6. Classification according to ontogeny

7. Agronomic classification

8. Classification based on leaf morphology

9. Classification based on serving special purpose

The evolutionary classification based largely on the typological methods has been adopted a number of fish taxonomist. Foremost among them are Gunther and Cope (1871) Boutenger (1904); Jordan (1923); Regan (1929); Berg (1940) and Romer (1959). Out of the various schemes proposed by aforesaid taxonomists, there is no agreement among the ichthyologists regarding the classification of fishes. Fishes constitute more than one half of all vertebrates comprising around 40,000 species.

The classification of Berg (1940) is most widely accepted, it is based upon the conclusions of Jordan (1923) and Regan (1929). Many ichthyologists consider Bergs classification as a minor revision. Berg scrutinizing the merits of the other classification proposals and make advanced classification, which is accepted all over the world.

Classification of fracture and its repair in large animal practice by external completion method.

Aim

To know the different level of fracture limbs. In order to access their method of repair (Fig.1).

Complete fracture- It is a fracture in which there is complete loss of bone continuity and the bone is divided into two or more fragments (Fig.1).

Green stick fracture- It is the fracture in which, the cortex opposite to the bending force fractures completely, while the cortex under the force remains in tact, commonly seen in immature animals, (Fig-2)

Overriding fracture-A fracture in which the fragments lie side by side, causing shortening of limb (Fig-3)

Transverse fracture-The fracture line here runs transverse to the long axis of bone. Such type of fracture is caused by bending forces (Fig-4).

Oblique fracture- In this the fracture line runs oblique to the long axis of the bone. Such type of fracture is caused by bending with axial compression (Fig-5).

Spiral fracture-Here the fracture line spirals along the long axis of bone. Such type of fracture is caused by torsion, twisting or rotational forces e.g. in humorous (Fig-6)

Comminuted fracture- In this fracture, at least three fracture lines inter connect each other at one point (Fig-7).

Fruit crops can be classified into many groups or categories based on certain criteria, which may vary according to climatic and soil requirements, growth habits and of late with consumer rating. Horticultural and botanical classifications are two important types of classification followed in fruit plants. Classification often helps to identify the names and to group the plants. It also gives an account about relatedness among them which further suggest the breeding possibility and grafting compatibility. Different types of classifications followed are discussed here:

CLASSIFICATION BASED ON CLIMATIC REQUIREMENT

Fruit plants are classified based on their climatic adaptability and it is also known as ecological classification. In horticultural point of view, this classification has got much significance. Fruit growers can select crops suited to a particular region by following the demarcations given here. Fruit plants are categorized into the following groups in this classification.

Temperate fruits

Fruit crops need exact climatic requirements for their growth and development, flowering and fruiting. These plants are grown only in places where winter is distinctly cold, they are deciduous and become dormant during this season. Plants should be exposed to specific chilling temperature for certain period for flower induction. These plants are suitable to higher elevations and they can withstand frost. eg. Apple, plum, peach, pear, almond, walnut.

Classification of fruits: Classification is the system of grouping or placing of an individual according to nomenclature. It is very useful to the pomologist, it helps to:

•    To identify and naming the crop.

•    To study the close relationship.

•    To know their hybrids and crossing behavior.

•    To know their compatibility & inter grafting ability.

•    To know their adoptability to soil & climate.

Pomology: Pomology is a branch of horticulture which deals the cultivation utilization and management of the fruit crops. eg. Mango, Banana, Citrus, Papaya, Guava etc. The term pomology is a combination of two words “Poma” in Greek means Fruits later subsequently transfer in to “Pome” in Latin word means Fruits and Logos means Study.

1. Fruit : Types and their Classification

Fruit:The botanical definition of fruit is a seed-bearing part of a flowering plant or tree that can be eaten as food

or

Fruits are matured ovaries plus any associated flower parts and contain the seeds of the plant. The ovary may be subdivided into two or more carpels (then termed compound ovary) each bearing one to many ovules. Individual carpels develop into sections of a whole fruit, as with citrus where each familiar segment of the fruit represents one matured carpel. If the ovary is not subdivided, then it is termed simple. The ovules will mature into seeds if fertilized. Fruit has three parts.

According to G.C. Ainsworth (1973) the fungus is free-living, parasitic or mutualistic, saprotrophs, necrotrophs or biotrophs and devoid of chlorophyll. Cell wall composition very variable, majority contain chitin and glucans, reserve materials glycogen, oil and mannitol, characteristic disaccharide and trehalose. Some yeast-like but majority with thread-like filaments, hyphae, branched profusely to form the vegetative mycelium on which spores are produced, asexually or sexually, free on hyphae or enclosed in complex reproductive structures. Separated mainly on morphology of the latter.

2.1 Divisions: Myxomycota

These are wall-less and quite unusual organisms only included in the fungi as mostly studied by mycologists. Possess either a plasmodium, a mass of naked, multinucleate protoplasm, which feeds any ingesting particulate matter and moves by amoeboid cells. Both of slimy consistencies hence slime molds. Four classes:

2.1.1 Class: Acrasiomycetes (Cellular slime molds)

Assimilative phase, free living amoebae which aggregate to form a pseudoplasmodium before reproduction.

I. Classification of fruit crops

1. Based on botanical relationship

2.1 INTRODUCTION

Owing to a varied agro-ecological and eco- edaphic condition prevalent in one or other part of the country, quite a large number of crops are grown in different parts of India. India is rich in bio-diversity with four hotspots out of twenty-five in the world. About 356 domesticated plant species having economic and botanical importance and 326 species with their wild relatives are found in Indian sub-continent. Besides the above, 9500 other plant species are also available. More than 50 different types of fruits, 50 different types of vegetables, 95 types of spices and condiments, medicinal and aromatic plants, plantation crops and ornamental crop plants have been recorded. To avoid confusion and identity, the horticultural plants are grouped into different categories based on similarity or dissimilarities. Grouping of the crop plants with similar characteristics is referred as classification.

Classification is system of placing an individual or a member in various groups or to categories them according to particular plan or sequence which is in conformity with the nomenclature. From time-to-time for purposes of convenience plants or fruits have been classified in various ways that makes possible to refer them to a large number of kinds under a group name without enumerating or specifying individually. The basis of these groupings varies according to the features of fruits or growth of the fruit plants that have been under classification at the time.

Knowledge of classification of horticultural plants is very useful to the horticulturists because it serves: (1) to identity and name them, (2) to afford at least some idea of the closeness of their relationship i.e. line of descent to other kinds, (3) to suggest with what other kind they possibly may or may not be interbred or crossed, (4) to suggest the kinds with which they possibly may or may not be inter-grafted, and (5) often to suggest certain soil and the cultural requirements, climatic adaptations etc. However, the classification of fruit trees or fruits and vegetables on the basis of consumer’s rating also gained attention in recent years. The consumers’ rating is mainly based on the size, shape, nutritive value and marketability of them. Each of these classifications is quite different from the other classification or groupings.

Basically, the fruit trees, as suggested by many authors, have been classified on the basis of their botany comprising of taxonomic ancestry, morphologic features, physiological functions, adaptability etc. or on the basis of agricultural and horticultural requirements. But the consumers’ rating has not been properly covered in the earlier classification. Generally based on botanical relationship the plants are classified as under.

Grouping plants in different categories on the basis of similarities and dissimilarities is referred to as classification, which helps for study of these crops in various perspectives. India is endowed with a rich diversity of horticultural plant wealth due to varied agro-climatic conditions. Number of fruits, vegetables, ornamental crops, spices, condiments, plantation crops, etc. is under commercial cultivation in different parts of the country under different sets of growing conditions.

The systematic study of all these crops becomes a difficult and more repetitive part. To avoid it; classification of horticultural crops on different aspects has been made to deal with all these plants separately. Classification of horticultural crops has been made in different groups on similarity or dissimilarity of attributes. Plants having similarity in either of the traits are placed under one group. The overall objective of the classification is to categorize the horticultural plants and make the recollections very easy and convenient.

CLASSIFICATION

• Wistar albino
• Sprague Dawley
• Long Evans
• Charles

Wistar Albino

Wistar albino is common strain found in most laboratories and used extensively for research. They have the following characteristics: (i) Less resistance of inflammation, (ii) No incidence of spontaneous tumor.

Sprague Dawley

Definition of Breed

A breed is a group of animal’s related similar characters like general appearance, size, features and configuration etc. A group of individual which have certain common characteristicsthat distinguish them from other groups of individuals is known as Species.

Types of Breeds
Domestic cattle belong to the family Bovidae, sub-family Bovinae and can be classified into Bos Taurus and Bos indicus. They have 30 pairs of chromosomes, interbreed and are distributed throughout the tropics. The domestication of Bos taurus cattle took place some 8000to 9000 years ago and Hamitic longhorn and shorthorn types are believed to be their ancestors. The origin of Bos indicus breeds (humped cattle) were in western Asia. Both humped and hump less cattle were introduced to Africa from western Asia and into America and Australia from Europe by the immigrants. The European cattle Bos taurus were introduced in the tropics to be raised as pure-bred sand crossbred with indigenous breeds. As a result of crossing of native cattle with European dairy breeds, large numbers of crossbreeds have been produced in various tropical countries, which are being used in selection programs. Zebu Bos indicus cattle were introduced into United States in the nineteenth century for crossbreeding with European breeds. Breeds resulting from crosses are used in the southern regions of North America and tropical South America. Most of the cattle breed in the tropics evolved, through natural selection, for adaptability and survival to local environments. Often, breeds resemble each other with slight morphological differences, but because of constant inbreeding in one locality, independent breeds have evolved. In general, the cattle from drier regions are well built and those from heavy rainfall areas, coastal and hilly regions are of smaller build.
Classification of Cattle Breeds
Most indigenous cattle breeds in the tropics are multipurpose (milk, meat, draught) and that only a few breeds have good milk potential. Physical and economic parameters for some of the important indigenous dairy breeds and new crossbred types developed in the tropics are discussed. Indian cattle breeds of cattle are classified in to three types as under: a) Milch breeds: b) Dual Purpose breeds: c) Draught breeds

The classification of living organisms has passed through several changes and has reached the present stage with the gradual assimilation of more and more knowledge about them. The classification is mainly based on the anatomy, life style, habits, habitats, metamorphosis and such other characteristics. Though the concept of classification of living organisms was perhaps started by Aristotle between 384 - 322 BC, it was the Swedish scientist Carl Linnaeus (1758) who presented the classification, which was acceptable to most of the Taxonomists. He propounded the binomial nomenclature of naming each and every organism of animal and plant origin with a generic and species name. In his classification, he was consistent in using Latin names for all the organisms. He was the originator of a regular system of classification in which he recognized larger and smaller categories, the larger ones comprising of a varying number of smaller ones. Because of his contribution in the field of Taxonomy, he is rightly called the ‘Father of nomenclature’. A.D.Imms later modified the system to some extent in 1961. However, Brauer (1885) laid the foundation of the modern system of classification of insects. He was the first one to emphasize the fundamental division into primitive wingless insects, the ‘Apterygota’ and the winged or secondarily wingless insects, the ‘Pterygota’. The latest code on classification and nomenclature was approved and published by the ‘International Trust for Zoological Nomenclature’, London in 1964.

1.    Kernel type: Dent, Flint, Floury, Waxy, Sweet and Pop corn 
        •    Dent corn (Zea mays indentata Staurt.)
        •    Flint corn (Zea mays indurate Staurt.)
        •    Pop corn (Zea mays everta Staurt.)
        •    Sweet corn (Zea mays saccharata Staurt.)
        •    Flour/soft corn (Zea mays amylacea Staurt.)
        •    Waxy corn (Zea mays ceatina Kulesh)

1. Village market is based on the classification of ________________

a) Volume of transaction

b) Location

c) Time span

d) Area coverage

2. Regional Markets are based on ___________

a) Location

b) Time span

c) Area coverage

d) Volume of transaction

3. The prices of commodities are controlled mainly by the extent of demand for the commodity rather than the supply of the commodity.

Classification of market

There are several bases on which markets are classified.

a. On the basis of location

On the basis of the place of location or operation, markets are of the following types:

Village market

A market which is located in a small village, where major transactions take place among the buyers and sellers of a village, is called a village market.

Primary markets

• These markets are located in big towns near the centres of production of commodities. In these markets, a major part of the produce is brought for sale by the producer-farmers themselves. Transactions in these markets usually take place between the producers/farmers and traders.

Under the selected breeding system selected males and females are mated. The breeding system can be classified into five different ways depending on their phenotypic and genotypic relations.
The five Breeding Systems are
(1) Random mating,
(2) Phenotypic assortive mating,
(3) Phenotypic disassortive mating,
(4) Genetic assortive mating and
(5) Genetic disassortive mating.
1. Random mating or Panmixia: It is a system of mating in which each male individual has an equal opportunity to mate with the female individual and vice versa. This mating system generally takes place in nature where the number of males and females are assumed to be equal.
2. Phenotypic assortive mating: In this type of mating animals which are phenotypically alike are allowed to mate among themselves. This is also called “like to like” mating.
3. Phenotypic disassortive mating: Here individuals which are phenotypically unlike are allowed to mate. It is also called “unlike to unlike” mating. For example, mating of tall with short individuals.
4. Genetic assortive mating: In this system individuals, which are closely related genetically are allowed to mate. This is also known as inbreeding.
5. Genetic disassortive mating: This system is just opposite to the previous system where mating takes place between less closely related individuals. This is also called as out breeding.

Improvements in microscopes enabled scientists to study the ‘invisible’ organisms – that is, those too small to be seen with the naked eye. They were able to show that certain of these microscopic creatures are responsible for the infectious diseases of higher organisms. Most of them are harmless, some are essential for life and some are used in the manufacture of products that are of benefit to humans.

A mutagen is a physical or chemical agent that changes the genetic material (DNA) of an organism and thus increases the frequency of mutations above the natural incidence. Errors during DNA replication, repair and recombination also causes spontaneous mutations naturally. Mutagens may be of chemical, physical or biological origin. The properties of each mutagen vary by causing damage to the DNA, and most often result in replication error.

1.1. Above ground feeders

1.1.1. Feeding on flower buds, leaves and bulbs.

Seed gall nematode: Anguina tritici

Leaf and bud neamtode: Aphelenchoides

Stem and bulb nematode: Ditylenchus

5.1 Fundamentals of Plant Nomenclature
(A) Plant Nomenclature
5.1.1 Definitions
Assignment of definite names to plants is called nomenclature. In the present botanical world, the nomenclature involves the principles governed by rules formulated and adopted by International Botanical Congresses. The rules developed by IBC are listed formally in a code called International Code of Botanical Nomenclature (Voss et al., 1983), abbreviated as ICBN. The major goal of ICBN is to provide one correct name for each taxon. Taxa (singular, taxon) are the taxonomic groups of any rank. The ascending hierarachy of taxa include species, genus, family, order, class and division.
5.1.2 Who is a Nomenclaturist?
A nomenclaturist is a taxonomist who assigns names to new taxa, determines the right names for old taxa according to the rules of International Code of Botanical Nomenclature, and finalizes the right name for a specimen according to an established system of classification.

There are thousands of diseases, which attack crop plants. Classification can be made based on several criteria. The various ways of classifying diseases of plants are given below.

A. Based on Type of Infection

1. Localized disease- affecting only a part of the plant; leaf spots and anthracnoses caused by different fungi.

2. Systemic disease- affecting the entire plant.

B. Based on Symptoms

Rusts, smuts, wilts, blights, cankers, mildews, rots, damping-off, die-back, scab etc.

There are number of diseases which attacks crop plants. Therefore It is mandatory to classify plant disease into more manageable and more specific group based on several criteria for easy and better understanding. Let us discuss one by one.

1. On the basis of type of infection

On the basis of type of infection disease can be classified into two types

There are thousands of diseases, which attack crop plants. Classification can be made based on several criteria. The various ways of classifying diseases of plants are given below.
A. Based on type of infection
1. Localized disease: Affecting only a part of the plant; leaf spots and anthracnoses caused by different fungi.
2. Systemic disease: affecting the entire plant.
B. Based on symptoms: Rusts smuts, wilts, blights, cankers, mildews, rots, damping-off, die-back, scab etc.
C. Based on the host plant
1. On the basis of host e.g. Diseases of apple, diseases of wheat, diseases of rose, diseases of coconut, diseases of coffee, diseases of cotton.
2. On the basis of host group- e.g. cereal crop disease, pulse crop diseases, oilseed crop diseases, root crop disease, forage crop disease, plantation crop disease etc.

Introduction
Plant diseases pose significant challenges in agriculture, affecting crop yields, quality, and overall plant health. To manage these diseases effectively, it is essential to classify them systematically. Accurate classification helps researchers and farmers understand the nature of the diseases, identify the causal agents, and implement appropriate control measures. This chapter explores various ways to classify plant diseases based on different criteria, such as the causal organism, symptoms, host range, type of crops infected, and whether the diseases are infectious or non-infectious.
Basis of Classification
On the basis of various criteria, plant diseases can be classified into the following categories:
1. Causal Organism
2. Symptoms
3. Host Range
4. Crop Plants Infected
5. Infectious vs. Non-infectious Diseases

Arrangement of plants and animals into groups according to their close resemblance, naming and describing them is called classification. Classifying the plants into groups is called systematic botany. The main aim of classification is to name the plant to describe them and to bring out their resemblances in order to throw light on their relationship and common ancestor. It is to indicate primitive and advanced plants systematically.

Need for Classification

It is not possible for anyone to study all the organisms. But if they are grouped in some convenient way the study would become easier as the characters of a particular group or a family would apply to all the individuals of that group. Classification allows us to understand diversity better.

Classification of plants

Entire plant kingdom is divided into four main groups.

1. Thallophyta 2. Bryophyta 3. Pteridophyta 4. Spermatophyta or Phenerogams

The nematode feeding on plant can be divided into above ground feeders and below ground feeders.

I. Above ground feeders

a) Feeding on flower buds, leaves and bulbs

Seed gall nematode : Anguina tritici

Leaf and bud nematode : Aphelenchoides

Stem and buld nematode : Ditylenchus

The nematode feeding on plant can be divided into above ground feeders and below ground feeders.

LAB constitutes a group of gram positive bacteria. They are nonsporulating, nonrespiring but aerotolerant cocci or rods, which produce lactic acid as one of the main fermentation products of carbohydrates, they do not have cytochromes. They belong to the phylum Firmicuttes, class Bacilli and order Lactobacillaceae. The group includes several genera such as Lactobacillus, Lactococcus, Bifidobacterium, Pediococcus, Enterobacter, Corynebacterium, Streptococcus, Leuconostoc etc.

The classification of pyrolysis processes plays a crucial role in understanding and categorizing the various methods used for thermal decomposition of biomass, waste materials, and carbonaceous feedstocks. This chapter provides an in-depth overview of the classification schemes employed in the field of pyrolysis. It discusses the different factors considered for classification, including temperature, heating rate, feedstock, reactor configuration, and operating conditions. Understanding these classifications is essential for selecting the appropriate pyrolysis process based on specific objectives, feedstock availability, and desired product yields.

Objective

1. To classify the various spices and condiments.

Types of classification: spices and condiments are classified on the following basis:

1. Classification on the basis of economic importance
2. Classification on the basis of parts used
3. Classification on the basis of climatic requirements
4. Classification on the basis of life cycle
5. Classification on the basis of taxonomy
6. Botanical classification