eChapters

DEFINITION OF VIRUS

Viruses are very small (submicroscopic) infectious particles (virions) composed of a protein coat and a nucleic acid core. They carry genetic information encoded in their nucleic acid, which typically specifies two or more proteins. Translation of the genome (to produce proteins) or transcription and replication (to produce more nucleic acid) takes place within the host cell and uses some of the host’s biochemical “machinery”. Viruses do not capture or store free energy and are not functionally active outside their host. They are therefore parasites (and usually pathogens) but are not usually regarded as genuine microorganisms.

Mathwas (1981) considers a virus as a set of one or more template molecules normally encased in a protective coat or coats of protein or lipoprotein, which is able to organize its own replication only within suitable host cells where its production is:

1. Dependent on hosts protein synthesizing machinery (ribosomes).
2. Organised from pools of required material rather than binary fission and
3. Located at sites which are not separated from the host cell contents by a lipoprotein bilayer membrane.

Bos (1983) defines virus as an infectious agent often causing disease, invisible with the light microscope (Sub-microscopic), small enough to pass through a bacterial filter, lacking a metabolism of its own and depending on a living host cell for multiplication. Viruses are small packages of host alien genetic information of one type. (RNA or DNA), either in one strand or in a few segment. Encapsulated together or separately and enclosed in a coat of one or more types of protein, some time with an extra coat (envelope) and some other constituents.

DEFINITION

Bacteria belong to prokaryota which encompasses organisms with a primitive type of nucleus lacking a clearly defined membrane .The bacteria are smaller than fungi and measure about 0.5 to 1.0 x 2.0 to 5.0µ.

Structure of Bacteria

1. A bacterial cell consists of a cellwall and a compound membrane enclosing protoplasm.
2. Inside the protoplasm, nucleus, vacuoles, mesosomes, polysaccharides, lipids, mitochondric granules and spores are found.
3. Externally bacterial cells may show capsules, pili, fimbrae and flagella.
4. The bacterial cell contains a characteristics cell wall.
5. The cell wall of bacteria is composed of a peptidoglycan. It is composed of acetyle-glucosamine and cetyle-muramic acid.
6. The rigid peptidoglycan layer is located between the cytoplasmic membrane and an outer multiple tract layer.
7. The latter layer is composed of lipoprotein . It is common in gram negative bacteria.
8. Many bacteria possess other intracellular membrane systems such as mesosomes and chondrioids.
9. The mesosome structure is formed by an invagination of the cytoplasmic membrane.

PROKARYOTES

Prokaryotic organisms are that in which nucleus is primitive type and nuclear material is not enclosed within the nuclear membrane.

Bacteria are placed in the kingdom “Prokaryotae” because of the prokaryotic cellular organization of the members. However, extremely diverse groups of microorganisms differing in morphological, physiological and ecological properties are found within this kingdom. In the beginning, description and information of bacterial systematics or classification was being published in the comprehensive volumes of “Bergey’s Manual of Determinative Bacteriology” (1923, first edition). The 9th edition of Bergey’s Manual, published in 1984 was the last of such comprehensive manual and from 1984 onwards it was renamed as “Bergey’s Manual of Systematic Bacteriology”. It is the most widely accepted and used reference document or book for classification and identification of bacteria. In the 9th edition, the kingdom Prokaryota (Monera) is divided into 4 divisons based on nature of the cell wall.These are : Gracilicultes; Firmicutes; Tenericutes and Mendosicutes .

GENERAL CHARACTERS

• Deuteromycotina includes the fungi in which the ‘perfect stage’(zygote, ascus, basidium) is either lacking or has not been discovered so far. Because of the apparent absence of any perfect stage or sexual phase, these fungi are commonly called ‘imperfect fungi’ or technically ‘Fungi imperfecti’.
• The characteristic feature of Deuteromycotina is the absence of sexual reproduction. The members reproduce only be asexual methods, and that too also chiefly by conidia, which develop on conidiophores.
• The conidia are produced either directly on the conidiophores or in some special types of fruiting bodies such as synnemata, acervuli, sporodochia or pycnidia.
• Fungi possess branched, septate and multinucleate mycelium except the unicellular yeast like members of Blastomycetes.
• Sexual reproduction is completely absent.
• Parasexuality is shown by some Deuteromycotina. Under this phenomenon, the process of plasmogamy, karyogamy and haplodization take place, but not at specified time or specified points in the life cycle of the fungus.

GENERAL CHARACTERS

• The members are terrestrial, and saprophytic or parasitic.
• The mycelium is well developed, branched and septate. The mycelium is of primary, secondary and tertiary type.
• Dolipore septum is present except rusts and smuts.
• Clamp connections present.
• Cell wall consists of chitin and glucans.
• Basidiomycetes reproduce asexually by conidia, arthrospores, oidia, fragmentation or budding.
• No specialized sex organs develop in Basidiomycetes.
• Plasmogamy takes place by somatogamy or spermatization.
• Sexual spores are basidiospores.
• They are exogenously produced on basidium.
• Usually four basidiospores are develop on basidium.
  The Basidiomycotina includes rusts, smuts, mushrooms, jelly fungi, puffballs, shelf fungi, toadstools, bird’s nest fungi, bracket fungi and earth stars.

GENERAL CHARACTERS

• Ascomycotina includes only such fungi in which the zygospores are absent and the perfect state spores are the ascospores.
• The Ascomycetes and Basidiomycetes are sometimes combindly called ‘higher fungi’.
• Cell wall is made up of chitin.
• Mycelium is well developed branched and septate.
• Asexual spores are non-motile conidia.
• Sexual spores are ascospores.
• Ascospores are usually 8 in an ascus.
• They are produced endogenously inside the ascus.
• The asci are usually grouped to form a definite type of multicellular fruiting body called ascocarp.
• The ascocarps are either cup or saucer shaped ( apothecium), flask shaped (perithecium), or closed, spherical and indehiscent (cleistothecium).
• The characteristic ascospores are present in sac- like body, called ascus and therefore these fungi are also commonly called ‘sac fungi’
• Yeast is single celled organism.

GENERAL CHARACTERS

• The majority of the members are saprobic. A few Zygomycetes are weak parasites, attacking plants and animals.
• Most Zygomycetes produce a well developed and branched mycelium, consisting of coenocytic hyphae.
• Cell wall is mainly composed of chitin.
• Motile cells or zoospores are absent.
• Asexual reproduction takes place by non motile sporangiospores called aplanospores.
• Sexual reproduction takes place by gametangial fusion.
• Gametangial fusion results in the production of a thick walled resting spore, called zygospore.

GENERAL CHARACTERS

• The Mastigomycotina includes all eumycota fungi which produce flagellated cells during their life cycle.
• Majority of them are with filamentous hyaline coenocytic mycelium.
• Cell wall contains cellulose.
• They show centric nuclear divison.
• The mode of nutrition is typically absorptive, because a majority of mastigomycotina contains some or other type of haustoria.
• They produce asexual spores called zoospores.
• Oospore is the sexual spores.
• Members of the class oomycetes are mostly aquatic but some are facultative or obligate parasites of vascular plants.

Taxonomy

Taxonomy is the science that deals with the identification nomenclature and classification of organisms.

Nomenclature

It is the system of assigning names to the taxonomic groups or organism according to international rules.

Systematics

It is scientific study of organisms with the ultimate object of characterizing and arranging them in an orderly manner.

GENERAL CHARACTERISTICS OF FUNGI

1. Thallus

The body of the fungus is called as Thallus, which is without stem root and leaves. It maybe Plasmodial, Pseudoplasmodial , Pseudomycelial or Mycelial. A single thread like filament is called as hypha. A hypha is made up of a thin, transparent tabular wall filled or lined with a layer of protoplasm.

A group of hypha constituting the body of fungus is called as mycelium may be septate or aseptate. i.e coenocytic.

a) Coenocytic or Nonseptate or Aseptate Mycelium

When mycelium is not divided by cross walls called as Cornocytic mycelium.

Depending upon the nature of parasitism with the host plant, mycelium is either ecotophytic or endophytic.

b) Septate Mycelium

When mycelium is divided by cross walls or septa called as septate mycelium.

Plant diseases are classified on the basis of type of pathogenic or non- pathogenic causes of the disease. The classification is based on the plant pathogenic organisms as follows.

PARASITES

They include both biotic and mesobiotic agents. The diseases are incited by parasites under a set of suitable environment. Association of definite pathogen is essential with each disease.

i. Biotic agents: They are also called as animate causes. They are living organisms. Biotic agents include:

History in general reveals chronological account of important events, contribution of persons who significantly influenced the thinking of their era and the interpretations of the observed facts or phenomenon over the period of time. The progress in plant pathology leading to the major land mark in mycology, plant bacteriology, plant virology and plant disease control has been described in chronological order for easy and better understanding of the student in following sub-headings.

DEFINITION

The term Plant Pathology is derived from Greek words- pathos (suffering) + Logos (study) i.e. the study of the suffering plant. Plant Pathology has two phases broadly-

• Science- understanding of the disease i.e. the theoretical consideration of the suffering plants and how do pathogens invade, how do plants defend themselves, what causes symptoms etc.
• Art- the application of the science to the field problems i.e. Diagnosis and Control.

Plant pathology or phytopathology is the branch of agricultural, botanical or biological science which deals with the cause, etiology, resulting in losses and management methods of plant diseases.

Plant pathology can also be defined as the study of the nature, cause and prevention of plant diseases. Plant pathology is related to most of the old and new sciences like biology, physics, chemistry, physiology, mathematics, genetics, soil science, biochemistry, biotechnology etc.

Study of plant pathology includes the study of sciences viz, microbiology, bacteriology, virology, mycology, nematology, protozology, phycology, unfavorable environmental factors, nutritional deficiencies and flowering plant parasites.

Plants make up the majority of the earth’s living environment as trees, grass, flowers, etc. Plants are the only higher organisms that can convert the energy of sunlight into stored, usable chemical energy in carbohydrates, proteins and fats. Directly or indirectly, plants make up all the food on which humans and all animals depend. Plants however also gets sick, grow and exhibit various types of symptoms and sometimes whole plant die. It is not known whether diseased plant feel pain or discomfort. If a plant is looking different from its community then it is equal to be disease one. Any biotic or abiotic agents which induce the disease in plant is referred as the cause of diseases.The causative agents of disease in plants are pathogenic such as fungi, bacteria, viruses, protozoa and nematodes and environmental conditions such as lack or excess of nutrients, moisture, light, etc to presence of toxic chemicals in air or soil. These biotic constraints can, at times, seriously compromise food security, For example, potato late blight, caused by Phytophthora infestans, struck Europe like ‘a bolt from the blue’ in the 1840s. In Ireland, about a million people died of starvation and more than a million attempted to emigrate. The reasons for this calamity were the arrival in Europe of a virulent strain of the pathogen, the high dependence of much of the Irish population on potato for sustenance, the lack of resistance in the plant to the pathogen, and weather conditions favorable to epidemic development. There have been other disasters caused by plant diseases such as the Great Bengal Famine of 1943 and the southern corn blight epidemic of 1970-71 in the USA, to name but two. In the former, an estimated 2 million people died owing to the high dependence of most of the population on a single crop, rice, which was attacked by the fungus Cochliobolus miyabeanus. In the USA, by contrast, although in some genus, Cochlobolus heterostrophus, alternative sources of nutrition were plentiful so no one died, although the effect on the agricultural economy was severe.

The first two of these heartbreaking examples demonstrate with brutal clarity that in areas of the world where a large proportion of the population is dependent on a single crop or a few crops, they are at risk should that crop fail owing to one or more devastating diseases. At the present time, the threat is partially great in developing countries, where populations are growing fastest, poverty is endemic , the population depends upon on locally produced staples, and the infrastructure of extension and R&D is often poorly resourced. The losses due to weeds, disease and insects have been estimated to around 40% in the developing and underdeveloped countries. If the post harvest losses (15-20%) are also added , the situation becomes even more alarming.

The transition from conventional to organic farming requires numerous changes. One of the biggest changes is in the mindset of the farmer. Conventional approaches often involve the use of quick-fix remedies that, unfortunately, rarely address the cause of the problem. Transitioning farmers generally spend too much time worrying about replacing synthetic input with allowable organic product instead of considering management practices based on preventative strategies. Here are a few steps new entrants should follow when making the transition to organic farming:

20.1. Understand the Basics of Organic Agriculture and the Organic Farming Standards

Since organic production systems are knowledge based, new entrants and transitional producers must become familiar with sound and sustainable agricultural practices. Transitional producers should be prepared to read appropriate information, conduct their own trials and participate in formal and informal training events. As mentioned, switching from conventional to organic farming is more than substituting synthetic materials to organic allowed materials. Organic farming is a holistic system that relies on sound practices focused on preventative strategies. Since there are often few organic remedies available to organic producers for certain problems, prevention is the key element in organic production.

In food production remarkable progress has been made in the last fifty years in agricultural production and self – sufficiency (Food security) has been reached. Yet nutritional security seems to be a distant goal. With depleting natural resources and increasing threat to the environment, sustainable crop production is attracting the attention of the scientists, farmers and administrators. Due to over exploitation of natural resources and indiscriminate use of agro chemicals, green revolution also brought in quite a lot of miseries which focus the urgent need to have EVERGREEN REVOLUTION that is sustainable, leading to food and nutritional security to the rural poor. At this juncture it will be more appropriate to practicing organic agriculrure through the integration of traditional wisdom and modern scientific knowledge in synergy with nature.

19.1. Eco-friendly Technologies for Rice Cultivation

A sound package of eco-friendly technologies to grow rice is being successfully adopted by a few progressive farmers in Puliangudi village in Tirunelveli district of Tamil Nadu. “The technologies work well with indigenous rice varieties such as Kitchili Samba. The cost of cultivation is substantially reduced and the organic rice fetches a premium price in the market,” says Mr. P. Gomathinayagam, a pioneer in organic farming in Puliangudi.

In India, there are two accreditation systems for authorizing Certification and Inspection agencies for organic certification. National Programme on organic Production (NPOP) promoted by Ministry of Commerce is the core programme which governs and defines the standards and implementing procedures. National Accreditation Body (NAB) is the apex decision making body. Certification and Inspection agencies accredited by NAB are authorized to undertake certification process. The NPOP notified under FTDR act and controlled by Agricultural Processed Foods Export Development Authority (APEDA) looks after the requirement of export while NPOP notified under APGMC act and controlled by Agriculture Marketing Advisor, Directorate of Marketing and Inspection looks after domestic certification. Currently 20 certification agencies have been authorized to undertake certification process.

National Programme on Organic Production

National Program on Organic Production (NPOP) was launched during 2001 under the Foreign Trade & Development Act (FTDR Act). The document provides information on standards for organic production, systems criteria, and procedures for accreditation of Inspection and Certification bodies, the national organic logo and the regulations governing its use.

Realizing that nematodes cannot be eliminated, and that we must live with them, the overall goal is to keep the population density as low as possible. The economic threshold is the density of nematodes where the losses incurred exceed the cost of nematode management. It is not advisable to depend on a single method to control nematodes. Efficient management requires judicious and careful integration of several which will result in reduction of nematode populations. Important components of non chemical methods of nematode management program are considered in this chapter.

17.1. Organic Amendments

Manure and fertilizer applications are essential part of growing any crop. Besides supplying required essential nutrients theyhelp in many ways directly or indirectly by suppressing harmful organisms including phytonematodes. The use of organic amendments against nematodes was demonstrated by Linford et al., in as early as 1938. FYM and cattle urine have found to reduce nematode population. Biogas plant waste slurry was found to be effective for nematode management. Compost of water hyacinth, oilcakes, cellulose amendments like sawdust, wheat straw, rice husk, rice hull ash, green manuring with legumes, green leaf incorporation are useful to keep nematode populations low. Non - edible oilcakes like those of neem, karanj, mahua, caster, cotton as well as edible oilcakes groundnut, mustard sesame, coconut have been recommended at 2 - 2.5 t/ha for reduction of root knot and other nematode population in soil. Miscellaneous substances like decaffeinated tea waste, rice hull ash, chicken manure, tannery and food and fruit processing waste, market and domestic organic refuse, dead vegetation and crop stalks, wood shaving, etc. have been recommended for root knot nematode management. Castor leaves (40g/kg) along with NPK at 75:25:37.5 kg/ha achieved reduction of M. javanica population on tomato.

Paddy is cultivated about 45 m ha in India, less than 1% is under organic cultivation.

16.1. Varieties

Good quality fine varieties like Ponni, Super ponni, insect and disease resistant varities must be selected for getting higher yield and returns.

16.2. Seeds

Organically produced seeds only must be used.

16.3. Seed Treatment

For 1 kg of seeds 20 g Azospirillum, Pseudomonas and 10 g Phospobacteria must be used with rice gruel.

Panchagavya spray @ 1% for treating the seeds.

15.1. IFS Components Tested for Wetlands

Area Allocation;

In 1 ha of land

75 % - Cropping

10 % - Fodder cultivation

3 % - Goat shed

12 % - Fish pond

Possible Integrations:

14.1. Water Source Identification

• In places where Ficus religiosa tree is found, underground water will be more.
• Underground water will be more in places where the neem tree with more knots is found.
• In places where termite hills are found, underground water will be more.
• Farmers are practicing traditional method of using neem stick, metals etc. for finding the water resource in underground for digging wells. While they are walking with this stick on hand it will be rottate automatically at the place where underground water is surplus.
• Some farmers are using the magnetic stones for identifying water sources. Magnet is tied with a thread and held like a pendulum while walking over the fields. The magnet will rotate automatically at the place where underground water is more and this is taken as the indication for digging wells.

13 1. Rishi Krishi

Drawn from Vedas, the Rishi Krishi method of natural farming has been mastered by farmers of Maharashtra and Madhya Pradesh. In this method, all on-farm sources of nutrients including composts, cattle dung manure, green leaf manure and crop biomass for mulching are exploited to their best potential with continuous soil enrichment through the use of Rishi Krishi formulation known as “Amritpani” and virgin soil. 15 kg of virgin rhizosperic soil collected from beneath of Banyan tree (Ficus bengalensis) is spread over one acre and the soil is enriched with 200 lit Amritpani.

It is prepared by mixing 250 g ghee into 10 kg of cow dung followed by 500 g honey and diluted with 200 lit of water. This formulation is utilized for seed treatment (beej sanskar), enrichment of soil (bhumi sanskar) and foliar spray on plants (padap sanskar). For soil treatment it needs to be applied through irrigation water as fertigation. The system has been demonstrated on a wide range of crops i.e. fruits, vegetables, cereals, pulses, oilseeds, sugarcane and cotton.

12.1. General Practices for Storage

• Lime juice is mixed with grains and then sun dried before storage to prevent insect pests (Farmers in Nigeria).
• Seeds are safely stored in earthern pots after mixing with the leaves of neem and Vitex negundo (Farmers in Gujarat, India).
• Drying seeds and grains of all the crops on the new moon day before storing to avoid pest attack.
• Store seed materials in earthen pots which are kept on the ‘Paran’ directly above the furnace in kitchen. The smoke acts as a repellent.
• Grains, trees etc. harvested on full moon day are raqre prone to storage pest attack.
• Mixing the dried leaves of neem with seeds while storing them.

Change in weather affects growth and development of plants. The extent of these effects depends upon the range or severity of change of weather. It is very much possible to change the weather in relatively small area to reap better harvest. Micro weather modification is defined as, “The manipulation of weather elements at increasing or decreasing the duration, intensity, quality etc., for desired effects at microlevel of crop under investigation”.

The climate near the ground can be managed partly by influencing the moisture status and temperature of the upper soil layers, e.g. by mulching and partly by action above the ground e.g. by shading or use of wind breaks.

Soil regeneration is about bulding or making topsoil. It is a particular form of ecological regeneration within the field of restoration ecology is the act/idea of replenishingthe top soil with beneficial nutrients casing natural methods. Time required from inorganic to organic would be about 60 to 200 days depending upon the situation. Once the inorganic fertilization is stopped, following actions facilitate quick conversion:

• Apply Farm yard/Poultry manure available in the farm as a basal dressing.
• Sow 25 kg of multi varietal seeds (MVS) in one acre.
• Allow it to grow up to 60 days.
• Inoculate the soil with the bio-agents like Azospirillum, Phosphobacterium, Pseudomonas flouresens, Trichoderma viride on 30 days after sowing (DAS).
• Incorporate in situ 60 DAS (30 t ha^-1 biomass is generated on 60 DAS) green manures.

9.1. ITKS for Seed Treatment and Sowing

• Yield of almost all the crops depends on seed quality.
• Even if it is a quality seed, it should be a dried one because well dried seeds will have higher longevity and keeping quality.
• It better to change the seeds at least once in two years.
• To maintain the seed viability and prevent it from outside damage, the outer shell is not separated.
• The seeds are generally stored along with the leaves of neem (Azadirachta indica), pungam (Pongamia pinnata), notchi (Vitex negundo) and thumbai (Leucas aspera).
• Six weeks nursery period is enough for six months duration of the crop.
• Shallow sowing is followed in dry lands.
• Severing the broadcasted seeds in dry lands with soil.
• Dragging, over the fields, the thorny branches with weight over them for covering seeds the sown on dry lands.
• It is better to start planting from ‘Sani moolai’ (north east) of the field to get higher yields.
• It is better to perform sowing and planting operations during evening hours.

8.1. Documented ITKs on Moisture Conservation

The ITKs were documented under following specific categories

• Agronomic Measures
• Tillage
• Bunding & Terracing (Mech. & Vegetative barrier)
• Land Configuration
• Soil Amendment / Mulching
• Erosion Control & Runoff Diversion Structures
• Water Harvesting, Seepage Control & Ground Water Recharge

7.1. Rice

• Treatment of paddy seeds in diluted bio gas slurry for 12 hours increases resistance of seedlings to pests and diseases.
• During panicle formation in paddy, the flowers of Cycas circinalis are placed on sticks in paddy fields @ 4/ac. Its unpleasant odor repels ear head bugs.
• About 30 kg of tamarind seeds are applied for an acre of paddy field 1 day after transplanting to boost up the crop growth and yield.
• Soaking the paddy seeds in diluted cow’s urine before sowing, considerably reduces the incidence of leaf spot and rice blast
• Presoaking of paddy seeds in milk increases its resistance against ‘tungro’ virus and ‘stunt’ virus
• For control of red leaf spot disease in paddy, the seeds are soaked in ‘Pudina’ leaf extract (Mentha sativa) for 24 hours
• ‘T’ shaped bamboo stands are placed in many places in the paddy fields so that birds can sit on them and feed on the larvae and adults of rice pests.
• Sowing on eighteenth day (Aadipperukku) of Tamil month Aadi (Jul-Aug.) ensures good harvest.
• Daincha (Sesbania spp.) seeds are sown on paddy main fields when paddy nursery is raised and the grown up daincha is ploughed in-situ during field preparation.
• Plough the main field for four to six times for better yield.

Indigenous Technical Knowledge (ITK) based inputs (Most of the ITK’s needs scientific validation before large scale adoption)

Is the systematic body of knowledge acquired by local people through the accumulation of experiences, informal experiments, and intimate understanding of the environment in a given culture (Rajasekaran, 1993). Learning from ITK can improve understanding of local condition and provide a productive context for activities designed to help the communities. In addition, the use of ITK’s assures that the end user of specific agricultural development projects are involved in developing technologies appropriate to their needs’. Yet, ITK is still an underutilized resource in the development activities. It needs to be intensively and extensively studied, and incorporated into formal research and extension practices to make agriculture and rural development strategies more sustainable.

Many of our indigenous practices in agriculture and allied fields have been replaced by the so-called modern technologies and they have become obsolete, especially among the younger generations. Now these indigenous practices are endangered ones and these are a possibility for them to become extinct particularly during this era of globalization, liberalization and commercialization. Now the need has come to re-examine and then gradually re-introduce the effective traditional technologies of crop production.

Therefore, there is a need to systematically document the ITK as they are the unwritten body of knowledge. There is no systematic record to describe what is, what it does, how it does, means of changing it, its operations, it boundaries and its applications. It is held in different brains, languages and skills in as many groups, cultures and environments. Tamil Nadu is also a treasure land of indigenous practices in agriculture. However, only a few attempts have been undertaken by social scientists to document the available indigenous agricultural practices but none has evaluated scientifically. The documented ITK practices are given below.

Insect pests cause huge losses ranging from 5 to 80% of even up to 100%. Acute food shortage following world war –II and Bengal famine (1943) due to failure of rice crop due to a paddy disease indicate the severity of the loss, caused by the pests and diseases. The insects in storage on an average consume and spoil an additional 4 million tones of grains every year. All this indicates the importance of plant protection by which we can save millions of tones of food grains which are otherwise eaten away by different pests. Losses due to insect pests in Indian agriculture are 23.3 per cent. One of the practical means of increasing crop production is to minimize the pest associated losses.

A pest is any organism which occurs in large numbers and conflict with man’s welfare, convenience and profit.

Pests are often controlled with man made chemicals which have many harmful effects, for example:

Weeds can be considered a significant problem because they tend to decrease crop yields by increasing competition for water, sunlight and nutrients while serving as host plants for pests and diseases. Since the invention of herbicides, farmers have used these chemicals to eradicate weeds from their fields. Using herbicides not only increased crop yields but also reduced the labor required to remove weeds. Today, some farmers have a renewed interest in organic methods of managing weeds since the widespread use of agro-chemicals has resulted in purported environment and health problems. It has also been found that in some cases herbicides use can cause some weed species to dominate fields because the weeds develop resistance to herbicides. In addition, some herbicides are capable of destroying weeds that are harmless to crops, resulting in a potential decrease in biodiversity on farmers. It is important to understand that under an organic system of weed control, weeds could never be eliminated but only managed. In organic agriculture weeds are the resources as they are mostly native to the field/areas of existence (Children’s of the soil)

Technical Knowledge (ITK) based special inputs / Techniques for plant growth

Growth of the plant has for long been believed to be due to the minerals absorbed from the soil and the food materials synthesized by the palnt. It is recognized that growth of the plant is very much regulated by certain chemical substances known as growth regulators. These substances are formed in one tissue or organ of the plant and are then transported to other sites where they produce specific effects on growth and development. These materials can be produced organically for improving plant growth.

3.1. Growth Promoting Substances

Are those organic solutions (like Panchagavya, Buttermilk & Coconut milk slurry, Amudhakaraisal) prepared using the plant and animal products, decayed fruit and other agricultural wastes. For example

Manure is the organic material derived from animal, human and plant residues which contain plant nutrients in complex forms. Manures are used as source of plant nutrients. They release nutrient after their decomposition. They are applied in large quantities

Advantages of Organic Manures

• Organic manure provides all the nutrients that are required by plants but in limited quantities.
• It helps in maintaining C:N ratio in the soil and also increases the fertility and productivity of the soil.
• It improves the physical, chemical and biological properties of the soil.
• It improves both the structure and texture of the soils.
• It increases the water holding capacity of the soil.
• Due to increase in the biological activity, the nutrients that are in the lower depths are also made available to the plants through manures.
• It acts as mulch, thereby minimizing the evaporation losses of moisture from the soil.

Presently the farming situation urges need to develop farming techniques, which are sustainable from environmental, production, and socio-economic points of view. Modern agricultural production throughout the world does not appear to be sustainable in the long run. Sustainable agricultural development “is the management and conservation of the natural resource base and the orientation of technological and institutional change in such a manner to assure the attainment and continued satisfaction of human needs for the present and future generations”. Such sustainable development in the agriculture, forestry and fishery sectors, conserves land, water, plant and animal genetic resources, is environmentally non-degrading, technically appropriate, economically viable and socially acceptable. Such concerns imparted a way to organic farming. It is the need of the day to understand the prospects and problems of organic farming to launch a successful and flawless organic production programme in the farm of environment.

Organic farming

It is the most widely recognized alternative farming system to chemical agriculture evolved during 1940’s largely in response to the publication of J.I Rodale in the U.S., Lady Eve Balfour in England and Sir Albert Howard in India. In 1980, USDA released a landmark report on organic farming. The report defined organic farming as follows;

“Organic farming is a production system, which avoids or largely excludes the use of synthetically compounded fertilizers, pesticides, growth regulators, and livestock feed additives. To the maximum extent feasible, organic farming systems rely upon crop rotations, crop residues, animal manures, legumes, green manures, off-farm organic wastes, mechanical cultivation, mineral bearing rocks, and aspects of biological pest control to maintain soil productivity and tilth to supply plant nutrients, and to control insects, weeds, and other pests”.

11.1 Planning

• Upon receipt of production program verify that crop sowing dates fall into crop windows identified for the particular area and allot accordingly. Check the quality of lots produced in previous season, if available.
• Assign crop location (Open field, Green house, Insect Proof Net / Cage etc) according to crop needs, site conditions and degree to which these conditions can be manipulated efficiently to meet the crop needs. Always adhere to optimum crop conditions.
• Identify material and personnel needs based on the production program and coordinate timely arrival of both. Material and personnel must meet standards established by the production site.
• Identify material quality like A, B, D (First, Second and Dirty) based on the specs.
• Refer standard procedures or formulate some of them. Do not proceed if proper documentation does not exist.
• Plan training for laborers regarding crossing, flower morphology, anthesis, time of stigma receptivity etc.

Inventory management system is a computer based system for creating work orders at a processing plant, tracking inventory levels in the go downs, , sales and seed movement out of the processing plant. These modern systems avoid book maintenance and save lots of space. It will also tool for avoiding overstock or delay in movement of seed material for packaging. In most of the processing plants SAP is the most popular inventory management tool which is more efficient than others. SAP is basically a tool of enterprise resource planning which help in material management. The customised software can be used very effectively in a processing plant for the following operations.

Seeds are having a ability to survive and start a new generation when favourable conditions exists. However like other form of life, they cannot retain their viability indefinitely and eventually deteriorate and die. To retain viability and germination it is important to store in proper storage. Seeds harvested may not be useful for packaging thus making it to store for a period till the need for packaging arises. Seed storage is very critical task of seed processing. The success of seed processing is determined by safe storage. Since the vegetable seeds are expensive need modern techniques of storage. Based on the seed shelf life or longevity vegetable seeds can be divided into two types:

Orthodox Seeds : Orthodox seeds are long-lived seeds. They can be successfully dried to moisture contents as low as 5% without injury and are able to tolerate freezing temperatures. Most orthodox seeds come from annual temperate species adapted to open fields. At physiological maturity they contain moisture content of 30 – 50%. Most of the vegetable seeds are orthodox and hence there is lot of scope for proper storage. E.g-Tomato (6.0 %) and Peppers (7.0%

Recalcitrant Seeds : They are short - lived seeds, which cannot be dried to moisture contents below 30% without injury and are unable to tolerate freezing. They are difficult to ore successfully because of their high moisture content encourages microbial contamination and results in more rapid seed deterioration. Storage of these seeds at subzero temperatures causes the formation of ice crystals, which disrupts cell membranes and causes freezing injury. These seeds are from perennial trees in the mois t tropics such as coconut, coffee, cacao, citrus etc. These seeds mature and exists in their fruits and are covered with fleshy or juicy ariloid layers and impermeable testa. At physiological maturity they contain more moisture content (50- 70%) than orthodox seeds, even though their embryos are only about 15 % of the size of an orthodox seed embryo. In general recalcitrant seeds never go into dormancy but instead continue their development and progress towards germination.

Vegetable seed drying is the most critical stage for any shop floor activities. Only properly dried seed will be taken for processing and all the other activities from seed receipt to storage. Seed producers harvest the seed which will have more moisture than packaged seed. For example onion seed harvested when its moisture at 60% but eventually dried to 10-12% for safe storage and packaging. Seed drying is highly skilled and specialized activity without affecting the seed quality. Proper drying procedures are vital for storage and field performance of seed lots. Drying prevents germination of the seed, the growth of bacteria and mould and it reduces the conditions for development of insects. The moisture content of a seed is influenced by the humidity of the air because they are very hygroscopic in nature. The more moisture in the air, the higher the moisture content of the product. If seed are harvested during warm, humid weather, the moisture content of the seed will be high because the relative humidity of the air is high as well. It is necessary to dry the seed before it can be stored safely. The method of drying depends on the local conditions (climate, season, volume of the seed, type of seed etc)

Vegetable seed drying is the most critical stage for any shop floor activities. Only properly dried seed will be taken for processing and all the other activities from seed receipt to storage. Seed producers harvest the seed which will have more moisture than packaged seed. For example onion seed harvested when its moisture at 60% but eventually dried to 10-12% for safe storage and packaging. Seed drying is highly skilled and specialized activity without affecting the seed quality. Proper drying procedures are vital for storage and field performance of seed lots. Drying prevents germination of the seed, the growth of bacteria and mould and it reduces the conditions for development of insects. The moisture content of a seed is influenced by the humidity of the air because they are very hygroscopic in nature. The more moisture in the air, the higher the moisture content of the product. If seed are harvested during warm, humid weather, the moisture content of the seed will be high because the relative humidity of the air is high as well. It is necessary to dry the seed before it can be stored safely. The method of drying depends on the local conditions (climate, season, volume of the seed, type of seed etc)

Seed treatment is one of the important activities of the shop floor. The seed should be treated with various insecticides, fungicides and additives to protect it up to establishment. Some timesenhance quality parameters like vigour which is critical for better establishment. Since vegetable seeds are of very high value and low volume, investment on seed treatment will yield better not only for the seed seller but to the grower also. More number of plants in a field brings moreincome per unit area. Hence the farmer or grower who buys seed is ready to bear the cost of seed treatment making it an important aspect of seed processing.

Seed treatment refers to the application of fungicide, insecticide or both to the seeds to disinfect(deep seated) and disinfest (over seed coat) them from seed borne or soil borne pathogenic organisms and storage insects. It also refers treating seed for enhancing quality by subjecting the seed to solar energy exposure or immersion in hot water or dry heat treatment or priming also.

The term seed blending is nothing but seed mixing done based on certain principles. It is simply combining two or more seed lots of same variety or hybrid of specified quality. The blendingmayinvolve lots which mayhave different quality in terms of germination. Usually individual seed lots are much better compared to blended lots but from the point of efficient inventory management blending is advisable. The main purpose of blending is to pool all the variable lots in to a larger bulk and mix the constituents effectively so that each pocket of seed has a uniform quality.

Seed processing is specialized activity and also a tool to improve seed quality further to an acceptable standard. Seed quality parameters like germination, vigour or genetic purity can be improved using processing. Say a seed lot having a minimum standard of 90% germination, but the competition in the market offering seed quality 92 or 95 % then to meet the market demand we can process the seed lots using re-milling or re-conditioning techniques. Also sometimes simple techniques like liquid density separation which uses specific density of the seed to separate good seed from inferior quality can be considered. Various case studies on processing to improve seed quality are given here.

The processing of the seed refers to mainly pre-cleaning and sizing. The sizing is up gradation of seed lots based on size, shape or length. In this chapter processing with main reference to sizing or upgrading is given. Sizing or upgrading is done by using different screens in an air screen cleaner, gravity separator, seed blower, indent disc cylinder, belt grader or some time colour sorter. Here specific tasks like use of screens in an air screen cleaner, rubber belt angles when using a belt grader, disc type when using indent disc cylinder or special arrangements in a gravity separator are given. The details of the machines or equipments with the principles of working were already covered in Chapter-3.

Vegetable seed cleaning and processing are two important aspects of seed post-harvest management. These steps are very essential to maintain the quality of the seed till its next sowing season. The quality of seed produced is dependent on the moisture content and various admixtures. To provide quality seed to farmers, it is very essential to clean seed to its maximum quality. The seed quality attributes like moisture, free water activity, to be controlled in germination, vigor and viability are upgraded during seed cleaning.

Seed cleaning is the term used as a part of processing means separation of admixtures from a particular seed lot. The physical characters like bigger clods, sand, soil, chaffy material, inert matter etc. will be removed during seed cleaning. Seed processing on the other hand is relatively broad term referring to the process of removal of dockage in a seed lot and preparation of seed for marketing is called seed processing. The price and quality of seed is inversely related to dockage, which should not exceed a maximum level permitted for different crops for seed certification. Due to the operation of processing the level of heterogeneity of seed lot gets narrowed down. The heterogeneity occurs in a seed lot due to following reasons:

The vegetable seed production in India work on the principle of buy back or contract farming where the production agent or organizer distribute the plots of seed production to growers. The grower is responsible for the rising of seed crop till harvesting or pre-conditioning. The organizerguides the growers regarding the plant protection, roguing and pre-conditioning. The harvesting is entirely a responsibility of the grower but facility for pre-conditioning may be established by the seed organizer. The seed pre-conditioning includes activities like acid treatment on wet seed bases or operations which make seed ready for procurement. After the harvesting or pre-conditioning the seed will be procured by the organizer and head for the processing yard for grading & packaging.

2.1 Harvesting and Pre-conditioning

The methods of harvesting and pre-conditioning various with crop to crop. There are mainly two types of vegetables in terms of type of harvesting.

1.1 Introducution

Growing of vegetables is one of the most profitable allied activities of agriculture especially in small-medium land holdings and with limited water resources. Use of improved varieties and hybrids is very critical to make smaller land holdings profitable. Seeds of improved varieties and hybrids not only increase income to the tune of more than 30% but also reduce the use of plant protection chemicals. India being the second largest producer of vegetables in the world with 6.2 m ha of land and 85m MT production-use of improved seed is very important. The annual requirement of vegetables is estimated to be over 135m MT which can be only achieved through use of quality seed. India is predominantly vegetarian country and depends upon vegetables for their nutrients and minerals.

Vegetable cultivation is labour intensive, gives high returns and ensures nutritional security. To ensure these the supply of quality seed is very vital. Apart from seed production, its processing for seed quality to give the end user is of high importance. Unlike seed processing of field crops, vegetable seed processing is very technology driven since the volume is less and involve costly material. Improved processing efficiency brings more income for the grower and seller. The vegetable seed being low volume needs better technology for upgrading, size grading, blending, conditioning, processing, treatment and packaging. Vegetable seed processing is set of activities as mentioned here each of having a special focus on the quality.

Institutes under ICAR

1. Deemed Universities - 4
2. Institutions - 64
3. National Research Centres - 15
4. National Bureaus - 6
5. Directorates/Project Directorates - 13 State Agricultural Universities

1. The normal gestation period of buffalo is

   a) 280 days

   b) 290 days

   c) 300 days

   d) 310 days

2. The best crop of silage making is

   a) Maize

   b) Jowar

   c) Bajra

   d) Lucerne

1. The goal of —————— is to gather commodity from the field at proper stage of maturity With minimum damage.

   a) Harvesting

   b) Grading

   c) Sorting

   d) Handling

2. Harvesting in rose is done at —————— stage

   a) Loose bud

   b) Tight bud

   c) Fully open

   d) Partially open

1. Botanical name of All spice is__________ _________.

   a) Piper nigrum

   b) Zinziber officinale

   c) Curcuma longa

   d) Pimenta dioica

2. Saffron belongs to family _________

   a) Piperaceae

   b) Myrtaceae

   c) Iridaceae

   d) Orchidaceae