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Life cycle of nematode has six stages. The egg stage, first stage juvenile (J₁), second stage juvenile (J₂), third stage juvenile (J₃), fourth stage juvenile (J₄) and the adult stage.

The first four stages are the immature stages and are known as juvenile stages. The female lays eggs in soil or in plant tissues, singly or in groups as egg mass that hatch out into juveniles which are almost similar to adults appearance. The first moult occurs within the egg shell and the second stage juvenile comes out by rupturing the egg shells as J₂. In case of Xiphinema index, the juveniles are reported to emerge from the egg before the first moult. The juvenile cuticle is shed after each moult.

The egg

The nematode eggs are oval in shape. The eggs are covered by three membranes, the external protein layer which is the secretion of uterus wall, the middle chitinous layer or the true shell secreted by egg itself and the inner lipid layer (vitelline layer). The chitin content in the egg shell vary in different species of nematodes.

Eventhough nematodes occupy nearly every habitat on earth, they are remarkably similar in morphology and life stages. Despite their structural complexity, certain basic principles are common to all nematodes. Nematodes are triploblastic, bilaterally symmetrical, unsegmented, pseudocoelomate, vermiform and colourless animals. The plant parasitic nematodes are slender, elongate, spindle shaped or fusiform, tapering towards both ends and circular in cross section. The length of the nematodes may very from 0.2 mm (Paratylenchus) to about 11.0 mm (Paralongidorus maximus). Their body width vary from 0.01 to 0.05 mm. In few genera, the females on maturity assume pear shape (Meloidogyne), globular shape (Globodera), reniform (Rotylenchulus reniformis) or saccate (Tylenchulus semipenetrans). The swelling increases the reproductive potential of the organism. Radially symmetric traits (triradiate, tetraradiate and hexaradiate) exist in the anterior region. The regions of intestine, excretory and reproductive systems show tendencies towards asymmetry. The nematodes have one or two tubular gonads which open separately in the female and into the rectum in the male which also have the copulatory spicules.

The free living saprophytic nematodes are generally larger in size. The animal and human parasitic helminths may have length of few centimetres to even a meter or more. The helminth parasitising whale fish is about 27 feet long. The study on these animals and human parasites are known as Helminthology.

In light of the high population of nematodes, N.A. Cobb (1915) who is considered to be the father of American Nematology, provided a dramatic description of the abundance of nematodes. He stated, “if all the matter in the universe except the nematodes were swept away, our world still would be dimly recognisable. We would find its mountain tops, valleys, rivers, lakes and oceans represented by a film of nematodes.” The Papyrus Ebers suggested a knowledge of the human intestinal parasite, Ascaris lumbricoides and the tissue parasite, Dracunculus medinensis. In early Egyptian writings also these two human parasites have been described. In 1956, Borellus recorded his observations “Vinegar eels” the microbivorous or free living nematode occurring in most vinegar at that time. The statement “sowed cockle, reaped no corn” in Shakespeare’s “Love’s Labour’s Lost”, act 4, scene 3, as suggested by Thorne (1961) possibly the first record of plant parasitic nematodes in 1549. The nematode that Thorne suspected to be in that reference actually was described by Needham in 1743. Subsequently, discovery of microscope and developments in various disciplines of science led to the discovery of plant parasitic nematodes and the disease caused by them. Some of the important milestones on the history of plant nematology are listed below in chronological order.

Agricultural crops are being affected by a wide range of organisms such as insects, mites, fungi, bacteria etc. Another important and unseen enemy is known as plant parasitic nematodes. The study on nematodes is known as Nematology.

Nematology is an important branch of biological science, which deals with a complex, diverse group of round worms known as Nematodes that occur worldwide in essentially all environments. Nematodes are also known as eelworms in Europe, nemas in the United States and round worms by zoologists. Many species are important parasites of plants and animals, whereas others are beneficial to agriculture and the environment. Nematodes that are parasites of man and animals are called helminths and the study is known as Helminthology. The name nematode was derived from Greek words nema (thread) and oides (resembling). This book focuses primarily on plant parasitic nematodes, their morphology, anatomy, nematological techniques, taxonomy, classification based on their feeding habits, symptom of damage to crops, interaction with other microorganisms, biology of important nematodes viz., Meloidogyne, Heterodera, Rotylenchulus, Tylenchulus and Radopholus and nematode pests of important crops and their management.

Annual crop losses due to these obligate parasites have been estimated to be about $78 billion worldwide and $8 billion for U.S. growers. The estimated annual crop loss in Tamil Nadu is around Rs. 200 crores.

The soil in a hectare of agroecosystem typically contains billions of plant parasitic as well as beneficial nematodes. The damage to plants caused by nematodes is often overlooked because the associated symptoms, including slow growth, stunting and yellowing can also be attributed to nutritional and water related disorders.

Book Keeping

What is book keeping?

Book keeping is defined as;

1. The art of recording business transactions (pecuniary transactions) in a regulator and systematic manner.
2. Book keeping is the science and art of correctly recording in books of accounts all those business transactions that result in the transfer of money or money’s worth.
3. Book keeping is an art of recording day to day business transactions in a set of books in a most systematic manner.
4. It is the process of analysing, classifying and recording transaction in accordance with preconceived plan.

Popularly the term management is used to refer to the group of managerial personnel of an enterprise. But the use of the term management in this sense is not correct, because the managerial personnel of an enterprise are usually designated as ‘managers’, ‘executives’ or administrators. Strictly speaking the term management refers to functional concept of management. Management refers to the sum total of all those functions or activities, which relate to the laying down of policies, plans and purposes, securing men, money, machinery needed for the achievement of the organisational objectives, putting all of them into operation and supervising and checking their performances in order to ensure the productive use of human and material resources for the maximum benefit or profit of the organisation, its employees and society in general.

Management is the sum total of five principal functions namely planning, organising, staffing, directing and controlling. The functional areas of management include: a) Financial management, b) Personnel management, c) material management, d) Production management, e) marketing management and f) Office management.

Goods and services are created through process of production. After production they have to be transferred or moved from the original producers to the final consumers. This involves the creation of market and the undertaking of number of activities such as buying, assembling, transportation warehousing, risk bearing, financing, selling etc. This constitutes the subject matter of marketing. Hence there is the need for the study of market.

What is market?

Market is derived from the Latin word “Marcatus” meaning trade, merchandise, ware, traffic or place of business. In the ordinary language, market is a place where buyers and sellers meet personally and make their purchases or sales. But in the language of economics, market need not be a place but it may be an area or region meant for potential exchange between a group of buyers and sellers interested in negotiating the terms of purchase and sale of goods and services and such negotiations may be done face to face at a certain place or may be done through other means of communication such as mail, phone, cable, television or through business middle men. What ever may be the means of communication there will be free exchange or perfect communication between buyers and sellers so that a fairly uniform price prevails for a particular commodity over the whole area at any given time.

Economics

The term “Economics” is derived from the Greek words ‘OIKOS’ and ‘NOMAS’ or ‘NEMEIN’. ‘Oikos’ means house hold and ‘Nomas’ or ‘Nemein’ means management. So in its original sense economics means house hold management; i.e. satisfying as many wants of the house hold or family as possible by allocating the limited resources at the disposal of the family wisely among different wants. In the modern and practical sense Economics means management of day to day problems arising from unlimited wants and limited resources by wisely allocating limited resources to satisfy maximum wants. In other words economics is the study of how man manages his limited resources as it satisfies as many wants as possible.

The produced food grains have to be stored either for short or long duration for utilization in the coming times for food, feed and seed. In storage, these undergo 9.33 per cent losses due to various agencies such as rodents, insects and mites, microorganism and moisture in India, whereas, in other developing countries, the losses are as high as 30 to 50 per cent. Therefore, with an urge to produce more, there is still urgent need to protect the produce in the storage to meet the challenge. As a result of improved storage technology, the losses in Government Warehouses could be reduced to minimum but at farmers’ level, where 60-70 per cent of the produce is retained, the losses are still too high.

The management of insects in stored products is in transition from a dependence on regular applications of chemical insecticides to the use of integrated pest management (IPM). IPM involves understanding interactions between stored product environment and insects associated with stored products, and replacing all or most of the chemical applications with cost effective non chemical alternatives. The increased emphasis in adopting IPM strategies for stored product insects is primarily due to consumers’ demand for food free from pesticide residues. The transition from a heavy reliance on chemicals to little or no chemical input and increased use of non chemical approaches requires a thorough understanding of stored product insects, their identification, monitoring, biology, ecology and response to chemical and non chemical management options. The current scenario of stored grain protection in India depends totally and judicious use of IPM strategies. For safe storage of food grains, both the preventive and curative measures are required:

Insecticide resistance to both fumigants and contact insecticides is an increasing problem in controlling stored grain and grain product insects throughout the world (Table 14.1). Hence, persons engaged in food commodity storage and preservation world over are concerned about the resistance of stored product insects to contact insecticides and fumigants. It is, therefore, necessary to work out strategies to delay or minimize the probability of resistance evolution. Resistance to pesticides is the ability of a strain of insects to tolerate doses of toxicants which would prove lethal to a normal population of insects of the same species. Resistance results when occasional resistant individuals arise in a population and survive the pesticidal treatment. These survivors then reproduce and confer the resistance to their offspring in succeeding generations. Resistance is the ability of a population (of insects) to survive a dose (of insecticide) that would normally kill 100 per cent of a susceptible population. Insecticide resistance is a dynamic phenomenon dependent on biochemical, physiological, genetic and ecological factors.

The chances of development of insecticide resistance in stored grain insect pest are more because of their life style, i.e., to remain confined in limited area. This results in more common inbreeding of the homozygous resistant strain resulting into homozygous resistant progeny. At the same time their management, once detected, can be easily achieved with the application of sufficiently acceptable sufficiently higher dose of the most appropriate insecticide to eliminate all the resistant survivors

The insect pest of stored grains can be conveniently divided into two groups, i.e., coleopterous and lepidopterous, therefore, the subject on these two groups has been pooled accordingly.

All due precautions have to be exercised in handling pesticides because many of these leave toxic residues on treated food materials and plants which accumulate in higher concentrations in animals which consume these.

General Precautions

Read the precautions given by the manufacturer of the pesticides carefully. Store the pesticides under lock and key; prevent access of children to these; empty containers must be disposed off safely.

Blood and skin contaminations must be avoided.

The godown for fumigation must be made airtight by closing the doors, windows, ventilators, crevices etc.

In case of fumigation, the operator must use a suitable gas mask. It is a face-piece connected to a canister containing an absorbent material for the vapours of the fumigants by means of a flexible non-kinking breathing tube and provided with valves so that all air inhaled by the user passes through the canister and the exhausted air passes directly to the outside atmosphere through a non-return valve. The absorbent canister carries instructions indicating the number of hours for which it is effective in an atmosphere charged with the fumigant.

After the required exposure period, aerate the godown thoroughly. First open the entrance door, keep it open for 6-7 hours, then only enter and open other doors or windows.

Introduction

The increase in agricultural production, particularly food grain is one of the major problems of national planners to achieve the target in the food production. Our farmers have been utilized more and more the modern methods of agriculture including the use of chemicals for protection of crop and stored products against the pests. A successful farmer knows that what pests to expect on his crops and stored products, when and under what conditions their attack will be possible. But due to insufficient knowledge of chemicals and their application, our farmers use them without care and injudicious manner, therefore, these chemicals not only give poor kill of insects but also cause the hazards to man and domestic animals. Success in pest control operations depends on many factors such as correct identification of pest, proper timing of insecticidal application, right choice of chemicals and their formulations, doses and method of application.

Fumigants are still widely used for the control of insects and other pest organisms. Because of their unique characteristics and the great adaptability of fumigation technique, fumigants can often provide effective and economical control where other forms of pest control are not feasible. The development of light weight plastic sheets to enclose spaces or materials requiring fumigation has extended its use and made control procedures easier and much more adaptable. Among the fumigants, aluminum phosphide, ethylene dibromide (EDB), Ethylene dibromide- carbon tetrachloride (EDCT) etc. are most common in tropical and sub-tropical while methyl bromide is prevalent in temperate regions. Modern technology and research have also brought to notice certain problems with fumigants that are previously unknown. Among these, adverse effects on seed quality are most important. Thus, fumigants used in seed stores should not affect the viability of the seeds, should not be persistent, non-corrosive and highly diffusible.

A series of efforts have been made to initiate the work on post harvest grain technology in India. The history of post harvest grain technology in India goes back as early as 1888 when COATS published several papers from Calcutta related to biology of stored grain pests. The first professional was appointed in the year 1905, known as Imperial Entomologist, Harold Maxwell Lefroy adorned with this post. Lefroy (1906) for the first time gave a tentative list of storage insects, which was further supplemented by Fletcher (1914). The problems of grain storage were discussed at the entomological meetings held at Pusa, Bihar in the years 1917, 1919 and 1923. The first step towards establishing an Institute in India was in the year 1950 when Central Food Technology Research Institute (CFTRI) was established at Mysore (Karnataka) with a mandate to train personnel and evolve technology related to food processing and preservation. The Central Warehousing Corporation was set up on 2^nd March 1957 under the Agricultural Produce (Warehousing and Development) Act 1956. The Food Corporation of India was established on 1^st January 1965.

In India, the farmers in traditional bulk and bag storage for food, feed and seed stored about 65-70 per cent of the total food grains and seed purposes till next harvest. Rest 30-35 per cent are procured and stored by food grain organizations, like Food Corporation of India (FCI), Central Warehousing Corporation (CWC), State Warehousing Corporations (SWCs), cooperatives, rural godowns and other state government agencies. In 1958, the Department of Food established a centre at Hapur known as Grain Storage Research and Training Centre (GSRTC) with the main objective to train the personnel of state government engaged in food procurement, storage and distribution. This centre was upgraded during 1968-1973 with the technical and financial assistance of UNDP and GSRTC and redesigned as Indian Grain Storage Institute (IGSI). The field stations at Ludhiana and Bapatla (later shifted to Hyderabad in March, 1979) were established in 1968-69. Subsequently, three stations were also established at Jabalpur (1980), Udaipur (1981) and Jorhat (1981).

Since commencement of the settlement of world, the search for food had been uppermost, thereby, practising the conservation of food is a basic need for ensuring its ample supply to human being. The problem of food storage is growing fast day by day with the increase in the population. The existing shortage of protein and caloric requirements will not only be solved by growing more food and resorting to family planning measures but also by saving the produce from deterioration and wastage, and its efficient allocation to meet the growing requirement of population. In countries with varied climatic conditions, it is a steady struggle of man with insects, mites, rodents and microbes in getting the food stuff.

Need and Objectives of Storage

Since times immemorial, man adopted a particular system of storage and certain produce storage standards. Some of the storage methods are still in use in several regions, in the capacity varying from one kg to several hundred quintals, like hollowed gourds, skin bags, mud bins, excavated stones, woven baskets, underground pits etc., particularly in the tropics. The problems of storage in developing countries are more acute than that in well developed countries and a considerable disparity seems to be there in food availability. All need a food supply that should be nutritious, clean; free from insects, rodents, birds, other animal filth and harmful chemical residues. There are two types of needs, one immediately after harvest and the other in off season. There is no need of storing the produce for immediate requirement but for the latter case, the need to conserve produce properly is inevitable. Further, the need for storage has always arisen for one reason to distribute commodity in deficit production areas and the other based on improved quality standards. In all the way, therefore; growers, processors, transporters and warehouse owner must assist to comply with these requirements.

In the past several insect pests had entered India and are causing economically perceptible damage to native crops. The Government of India, in line with the International Standards on Phytosanitary Measures (ISPM), notified ‘Plant Quarantine Order, 2003’ to reduce the risk of introduction of exotic insect pests in India. The storage insect pests of quarantine concern for India have been listed in Table 9.1.

As the name indicates, micro-organisms are very minute, cellular, living organisms which cannot be seen with the naked eyes (however, large colonies of fungi can be seen). Micro-organisms affecting stored grain can be divided into the following groups in order of their significance:

1. Fungi
2. Actinomycetes
3. Yeast
4. Bacteria
5. Protozoa (not found in sound food grains)

Fungi, bacteria and actinomycetes are grouped under the Thallophyta of the plant kingdom. The most important factors for their normal development are: (i) Nature of Food, (ii) Moisture, (iii) Oxygen and (iv) Temperature.