eChapters

1. The initiator of a food web is

   a) Carnivores

   b) Herbivores

   c) Plants

   d) Decomposers

2. Fauna is term for

   a) Plant kingdom

   c) Animals

   b) Both (plant and animals)

   d) None of the above

1. The rice plant belongs to

   a) Short day plant

   b) Long day plant.

   c) Day neutral plant

   d) Etiolated

2. Cycoceal is a growth

   a) Growth inhibitor

   b) Growth hormone

   c) Growth regulator

   d) Growth stimulant

1. International Rice Research Institute is located at

   a) Mexico

   b) Philippines

   c) Nigeria

   d) Columbia

2. Use of combining ability as a measure of gene action was first suggested by

   a) Wright (1921)

   b) Griffing (1956)

   c) Sprague and Tatum (1942)

   d) Hayman (1954)

1. Genetic principles of seed production were given by

   a) Feistritzer (1975)

   b) Kadam (1942)

   c) Kadam (1936)

   d) Swaminathan (1970)

2. Objectionable weed seed in wheat seed production is

   a) Chandvel

   b) Johnsoon grass

   c) Sudan grass

   d) Wild rice

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.

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.

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.

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:

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.

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 .

DEFINITION

Plant disease in which no pathogens or parasites is associated with the cause is known as Non-parasitic disease. They are also called as non-infectious or physiological disorders. When no pathogen is found, cultured from or transmitted from a diseased plant, then the disease is said to be caused by a non-living or environmental factor. These diseases occur because of disturbances in the plant system by the improper environmental conditions in the air or soil or by mechanical influences.

For the accurate identification and diagnosis of plant disease and plant problems a foundational knowledge of terms and definitions is vital for developing concepts, doing research, discussing and communicating issues and providing clarity to your work. The following terms and definitions are basic to the study of plant pathology. They are, however, just a brief introduction to the vocabulary of the science. If you have limited or no background in the subject and you are just getting started, the concepts and terminology of plant problems can seem somewhat daunting. However, your vocabulary and skill will develop through exposure to diagnostics, experience and correct use of the appropriate terms.

Plant pathology is the study of plant diseases and the abnormal conditions that constitute plant disorders. Etiology is the determination and study of the cause of disease. A pathogen can be living or non-living, but usually refers to a live agent. A pathogen is an organism which causes a disease. Pathological is a condition of being diseased. Pathogenic is having the characteristics of a pathogen and pathogenicity is the capability of a pathogen to cause a disease.

A plant disease is an abnormality in the structure and/or function of the host plant cells and/or tissue as a result of a continuous irritation caused by a pathogenic agent or an environmental factor. A disease is not static; it is a series of changes in the plant. All plants, to some extent, are subject to disease. Plant disease is the result of an infectious, or biotic agent or a noninfectious, abiotic factor. Plant injury is an abrupt alteration of form or function caused by a discontinuous irritant. Plant injury includes insect, animal, physical, chemical or environmental agents.

A causal agent is a general term used to describe an animate or inanimate factor which incites and governs disease and injury. A causal organism is a pathogen of biotic origin. When a pathogenic agent is virulent it can cause disease and if the agent is avirulent it is a variant of a pathogen that does not cause severe disease.

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.

The availability of a plant pathogens in given area presupposes its ability to survive not only during its parasitic relations with hosts but also during those seasons in which the hosts are not growing. The latter part of continued existence of plant pathogens in which they remain in dormant condition to overcome the unfavourable condition of non availability of hosts is called “survival”. Pathogens may survive between crop seasons by means of specialized resting structures, by functioning as saprophyte in or on the soil or in diseased plant debris, or by living insome intimate association withlivingplants or otherorganism.

Modes of Survival: The modes of survival of plant pathogens are described below:

1. Parasitic Survival

Organisms, parasitic on perennial plants (fruits, plantation and forest trees) survive in or on their hosts actively or passively depending on the environmental conditions. Certain bacterial pathogens viz, X. campestris pv citri, X. campestris pv jugalandis, X. campestris pv. Pruni and Erwinia amylovora are known to be carried over perennially in holdover cankers or blighted twigs, which may produce bacterial ooze in favourable weather to fresh inoculums. Similarly several fungal plant pathogens like Colletotrichum gloeosporioides (anthracnose of mango), Oidium mangiferae (powdery mildew of mango), Podosphaera leucotricha (powdery mildew of apple), etc survive on infected organs of the plants. Along with cultivated crops, several undesirable plant (weeds, etc) both annual and perennial, grow independently in the nature. Such plants which belong to the same botanical family to which cultivated hosts belong , are known as collateral hosts. Some important examples include the survival of three Puccinia spp. causing wheat rusts in Indian subcontinent . These fungi survive in active sporulating stage on wild species of Triticum, Aegilops, Horedeum and Agropyron repens. Similarly, Rice tungro virus survive actively on Oryza spp., Echinocloa spp. and Leersia hexandra .

Ascorbic acid (vitamin C) is present in almost all fresh fruits and vegetables in varying quantities ranging from 0.02 to 1.0 mg per g fresh weight. It is most abundantly found in bittergourd and berries.

The method for estimation of ascorbic acid is given here below as described by Albrecht (1993). It is an easy and simple method based on titration technique.

Garden is like drawing room of the house. A well maintained drawing room always impresses visitors at first look and also gives idea about choice and taste of the house owner. Similarly, well maintained gardens at the house, office, institute etc. provide a good reflection of the owner’s inclination towards nature. Maintenance of gardens round the year and to keep them in presentable form needs proper planning. Knowledge on regular garden operations taken up in different seasons is also important.

Operations required to be undertaken for better maintenance is given below as quarterly calendar which will be helpful to formulate plan of action in advance.

4.1 Determination of Specific Surface Area of Soil

Specific surface area of a soil is defined as surface area per unit weight of soil and is expressed as m² g^-1. The specific surface of soil greatly influences the physical and chemical properties such as retention of water at high suction, swelling, plasticity, soil strength, cation exchange capacity and availability of nutrients. The basic principle of determination of specific surface is based on the amount of gas or polar liquid required to form a monomolecular layer on the soild. Knowledge of molecular size (diameter) and the mass of the adsorbate enables one to calculate specific surface of the adsorbent.

Principle

Dyal and Hendricks (1950) introduced a method for estimating specific area based upon the adsorption of ethylene glycol (EG) to form a monomolecular layer over the entire soil surface. The method involves adding EG to pretreated soil or clay sample and evaporating the excess EG in an evacuated system. The quantity of EG retained at the moment the evaporating rate decreases is proportional to the surface area. Later on Carter et al. (1965) suggested the use of ethylene glycol monoethyl ether (EGME) having high vapour pressure at room temperature than EG for determining surface area of the layer silicate minerals and soils.

9.1 Determination of Oxygen Diffusion rate (ODR) of Soil

The rate of movement of oxygen from atmosphere to respiring plant root cells is important for root respiration and thereby the growth and development of plant. While diffusion through the air-filled pores maintains the exchange of gases between the atmosphere and soil, diffusion through water films maintain the supply of oxygen and disposal of carbon dioxide from active root tissues which are typically hydrated.

Principle

Lemon and Erickson (1952) introduced a method for measuring oxygen diffusion in soil with the help of platinum electrode. The process measures the extent of chemical reduction of oxygen by the platinum electrode maintaining a constant potential of 0.65V with a reference electrode.

India produce a wide range of tropical, subtropical and temperate horticultural crops at different places by virtue of its varietals agro- climate conditions. The total annual production of fruits and vegetables is around 135.5 million tones, fruits being 48 million tones and vegetables around 87.5 million tones. India is the second largest producer of fruits and vegetable in the world. They are major sources of important valuable vitamins and minerals. Being highly perishable, fruits and vegetables can be preserved and processed either at farm level or at cottage scale/home scale during market glut season or extra seasonal produce from kitchen garden for later use. Farmers and entrepreneurs can set up their own processing units by adopting simple, low cost innovative processing technologies which will save post harvest losses of these perishable crops and also give good returns to grower and better earning to processor/ entrepreneurs.

Nursery

Definition: It is a small area or place where seeds are sown for getting baby plant to transplant in the main field. These baby plants are known as seedlings.

Generally, growing rootstock in fruit plants and small seeded vegetables like tomato, brinjal, onion, cole–crops etc are needed to raising nursery and further transplanting.

There are two types of nursery;

• Temporary nursery: This nursery is raised by soil in open condition.
• Permanent nursery: This nursery is raised permanently walled and often provided with overhead covering against rain or frost.

Training

• Training is related to shape and size of the plant.
• In this process, removal of part of the plant to develop a proper shape.
• It develops strong frame work of tree, balance between vegetative and reproductive growth and facilitate interception of sunrays to each and every part of trees.

Methods of training

Central leader system

• Main stem of tree is allowed to grow continuously.
• First branch is allowed to grow 45–50 cm height from ground level and other branches are allowed to grow on main stem at a distance of 15–20 cm.
• The tree attained Robust shape
• It is not suitable for high altitude and hot arid areas.

Plant growth

Definition: The quantitative increase in plant body such as increase in the length of stem and root, the number of leaves etc., is referred to as plant growth.

Plant development

Definition: The qualitative changes such as germination of seed, formation of leaves, flowers and fruits, falling of leaves and fruits is referred as developement.

Phytohormones

Definition: These are the organic substance or hormones produced by plants which in low concentrations regulate plant physiological process. It is synthesized in one part of plant and translocated to other parts. These are endogenous substance means naturally occurring in the plant.

Biofertilizers

Definition: Biofertilizers are defined as preparations containing living cells or latent cells of efficient strains of micro–organisms that help crop plant’s uptake of nutrient by their interaction in the rhizosphere when applied through seed or soil. They accelerate certain microbial process in the soil which augments the extent of availability of nutrient in a form easily assimilated by plants.

Types of biofertilizers

There are some types of biofertilizers:

1. Nitrogen fixing biofertilizers
2. Phosphorus solubilizing biofertilizers
3. Phosphorus mobilizing biuofertilizers
4. Biofertilizers for micro–nutrients
5. Plant growth promoting rhizobacteria

Scientists rely on a variety of endocrine, behavioral, autonomic nervous system and immunological end points to measure stress. Unfortunately, none of these measures has proved to be a litmus test for stress. Increased secretion of the adrenal glucocorticoids and cortisol has been found to be associated with stress and investigators frequently cite an increase in circulating cortisol as a proof of stress. Colborn et al., (1991) found that stallions secreted similar amounts of cortisol whether the stallions were restrained, exercised or permitted to mate with a mare. Serum cortisol concentrations are often used to evaluate stress, but due to the marked variability, faecal corticosterone has been used to evaluate stress in cattle (Morrow et al., 2002). Dairy cattle secrets cortisol during restrained and when approached by strangers. So it is difficult to simply use secretion of cortisol or any other hormone to differentiate between non threatening stress and distress. Further, complicating is inter animal variability in stress response. Even among the same breed some cows may produce more cortisol to the same amounts of thermal stressors.

Standardization

Standardization means establishment of standards for matters such as quality, size, weight and color. Once standards are set grading is possible using the criteria established in the standards. Thus, standardization involves establishment and maintenance of uniform measurements of produce quality and/or quantity.

Grading

Grading follows standardization. It is a sub-function of standardization. It is a method of dividing products into certain groups or lots in accordance with predetermined standard. Grading before sale enables farmers to get a higher price for their produce .Consumer get standard quality products at fair prices. It is easier for them to compare the prices of different qualities of a product in the market. It minimizes their purchasing risk, for they will not get a lower quality product at the given prices .e.g. eggs are graded into different categories based on set standards. Similarly cattle feed is also sometimes categorized into different grades based on established standards.

Plants and any from of living organisms cannot live without water, since water is the most important constituent about 80 to 90% of most plant cell.

2.1 Role of water in crop and crop production

(A) Physiological importance

•The plant system itself contains about 90% of water

•Amount of water varies in different parts of plant as follows

•Apical portion of root and shoot >90%

•Stem, leaves and fruits - 70 - 90%

•Woods - 50 - 60%

•Matured parts - 15 - 20%

•Freshly harvested grains - 15 - 20%

8.1 Moisture extraction pattern

The moisture extraction pattern reveals about how the moisture is extracted and how much quantity is extracted at different depth level in the root zone. The moisture extraction patter shows the relative amount of moisture extracted from different depths within the crop root zone. The moisture extraction pattern of plant growing in a uniform soil without a restrictive layer and with adequate supply of available soil moisture throughout the zone is shown in Figure. 8.1.

Whatever may be the source of irrigation water viz., river, canal, tank, open well or tube well, some soluble salts are always dissolved in it. The main soluble constituent in water are Ca, Mg, Na and K as cations and chloride, sulphate bicarbonate and carbonate as anions. However ions of other elements such as lithium, silicon, bromine, iodine, copper, cobalt, fluorine, boron, titanium, vanadium, barium, arsenic, antimony, beryllium, chromium, manganese, lead, selenium phosphate and organic matter are also present. Among the soluble constituents, calcium, sodium, sulphate, bicarbonate and boron are important in determining the quality of irrigation water and its suitability for irrigation purposes. However other factors such as soil texture, permeability, drainage, type of crop etc., are equally important in determining the suitability of irrigation water.

The following are the most common problems that result from using poor quality water.

The science dealing with the measurement of size of any microscopically visible microorganism is known as micrometry which is based on the principle of physics. Before measuring a cell, the diameter of the microscopic field must be established by means of optic devices, namely an ocular micrometer and a stage micrometer.

a)Ocular micrometer : It is a circular disc that is placed in the eyepiece. The disc is graduated in to several small divisions marked from 0 to 100.It is placed inside the eyepiece of the microscope. The distance varies according to the objective of the microscope which can be easily determined by using a stage micrometer.

b)Stage micrometer : It is a glass slide graduated in 1 mm. Again 1mm is divided into 10 large divisions and 100 small divisions (10 x 10 = 100 divisions). These divisions are equally placed therefore 1 small division is equal to 0.01 mm or 10 μm.

Conservation Agriculture

The agronomic measures for water conservation helps to control the evapotranspiration loss from soil and plant surface, reduces the splash effect of raindrops, checks topsoil erosion and runoff losses, permits a better intake of rainwater by improving the better soil physical environment and thereby conserves higher soil moisture for better plant growth and yield.

1. Mulching : It protects the top soil from erosion loss by controlling runoff, facilitates rainwater absorption by soil, increases the consumptive use of water by crops and hence the water use efficiency, regulates the hydrothermal regime of soil, reduces the evaporation component of the evapotranspiration, prevents soil crusting and plant nutritional losses and keep down the weed infestation. Dry soil mulch as created by stirring the soil surface with the inter-culturing implements helps to minimize evaporation loss from soil surface. Use of cover mulches like black polythene sheets or organic residues or crop stubbles on soil surface will act as barrier to reduce the evaporation losses. Post-rainy season crops (rabi crops) which live primarily on soil stored moisture derive more benefit from mulching.
2. Anti-evaporants : These are used to reduce the evaporation from the soil surface. Straw, sawdust, paddy husk, wood bark etc are used to arrest the evaporation from soil surface. Hexadecanol, a long-chain alcohol, is also used to retard the evaporation from soil surface. This chemical is resistant to microbial activity and degradation and remains active in the soil for more than a year. The main limitation in soil surface mulching is high cost involvement.