eChapters

The knowledge and principles from interconnected disciplines of bioengineering, material science and life sciences are combined in tissue engineering with the aim of developing a construct that can wholly or partly restore/maintain/augment the function of a damaged tissue or organ. Tissue engineering construct generally comprises cells on a suitable scaffold. The ultimate functionality of a tissue engineering construct is mainly dependent on the cell behavior on scaffolds. The proliferation and cell viability on scaffolds varies from one cell type to another and from one species to another. So it is important to investigate individual cell-scaffold combinations.

The similarity in structure and composition to bone mineral, osteoconductive properties, ability to integrate with the bony tissue and absence of immune response makes hydroxyapatite [Ca10 (PO4)6(OH)2] the choice of calcium phosphate biomaterial with only disadvantage of slow rate of resorption. On contrary, silica–calcium phosphate composite in comparison to calcium phosphate is rich biomaterials having a faster resorption rate. Studies have shown that coating of hydroxyapatite with a calcium silicate containing layer encourages cell proliferation and osteogenic differentiation of human bone marrow-derived stromal cells.

In this chapter a composite scaffold (calcium silicate, hydroxyapatite and tricalcium phosphate), namely HASi with elements in the following percentages: 66.36 % - calcium, 25.35 % - phosphorus and silicon - 8.29 % and porosity of 50 – 500 µm is undertaken to evaluate the rBMSC proliferation and differentiation properties in vitro with the aim of assessing cytocompatibility of HASi and rBMSC in terms of cell attachment, cell morphology, cell proliferation and osteogenic differentiation.

Disruption of the cellular or anatomical continuity of the normal organ structure is known as wound. Healing involves migration, infiltration, proliferation and differentiation of several cell types like keratinocytes, fibroblasts, endothelial cells, macrophages, and platelets which are culminate as an inflammatory response, new tissue formation and wound closure. Healing of the wound starts from the moment of the injury and can continue for varying periods of time depending on the extent of wound. The process of wound healing involves coagulation, inflammation, formation of granulation tissue, matrix formation, remodeling of connective tissue, collagenization and acquisition of wound strength.

Chitosan is a -1, 4-linked polymer of glucosamine (2-amino-2-deoxy—D-glucose) and lesser amounts of N-acetylglucosamine. It is a derivative of chitin (poly-Nacetylglucosamine) which is the second most abundant biopolymer after cellulose. Chitosan is first discovered in 1811 by Henri Braconnota, a French chemist and pharmacist. Later in the century, chitin is found in crustaceans (such as crabs, lobsters, shellfish and shrimp). Chitosan is a biodegradable polymer and it accelerates wound healing. It has been reported that chitosan permits regeneration of tissue elements in skin wounds and has positive application effects on wound healing.

Full thickness burn wound will not heal spontaneously which need early excision and adequate coverage to prevent fluid loss and risk of infection. Major portion of the skin is lost during burn injury which is the active layer for protecting the entry of micro organism from outside environment. So far, meshed autologous skin graft is regarded as the gold standard for treating extensive full thickness burns. However, their frequent use may be hampered by several impediments such as limited availability, donor site morbidity, associated with additional scarring. Severe burn patients invariably lack additional skin donor site. Moreover, creation of donor site in burned patient is equivalent to second degree burn and which further increase the total body surface area affected (TBSA). In past decades, numerous biomaterials have been investigated for the use as a dermal skin substitute for burn patients but none give promising results. The innovative tissue engineered bioactive materials offer potential tissue regeneration and prevent the tissue deterioration.

The extracellular matrix (ECM) derived naturally from mammalian tissue have been successfully used as scaffold for tissue reconstruction and wound management in clinical applications. ECM can be derived from various tissue or organs of different species but most commonly, porcine small intestinal submucosa and urinary bladder have been successfully used as scaffold for reconstruction. ECM is obtained by process of decellularization that involves the use of various ionic and non ionic detergents, acids, enzymatic solutions and mechanical/physical methods.

The liver is an organ that plays a central role in maintaining metabolic homeostasis, in its functions of metabolism, synthesis and storage of nutrients. The cells in the liver are parenchyma cells and non- parenchyma cells. The former include hepatocytes (80% of the cell population) and the later includes endothelial cells, Kupffer cells, lymphocytes and stellate cells. Liver dysfunction or failures are having different etiologies. Liver cancer has the fifth highest cancer incidence in the world, and is the third highest cause of cancer related deaths, with resection of the liver remaining the only curative option.

Following liver injury, the repair process involves two distinct phases: a regenerative phase, in which injured liver cells are replaced with regenerated hepatocytes; and a phase known as fibroplasia or fibrosis, in which connective tissue replace normal parenchyma tissue. The process even though initially beneficial becomes pathogenic when it is not controlled appropriately. Extensive accumulation of extra-cellular matrix (ECM) components ultimately leads to cirrhosis and liver failure. Thus, the ideal strategy to treat liver injury is to generate new hepatocytes replacing damaged cells without causing excessive ECM deposition.

3.1. Downy mildew of peas
It is an important disease of pea crop particularly in those areas where cool and wet climate is prevalent during its cultivation. The disease during favourable weather conditions causes considerable yield losses.
Pathogen: Peronospora viciae (formerly P. pisi)
Host range
Vigna faba, Vigna sativa. Pisum arvensis, P.sativum, Lathyrus sativus, Vicia hirsuta, Vicia sativa, Vicia villosa (Dixon, 1981).
Geographical distribution
Reports of the pathogen are from different countries on different crop host.
On Pea- Berkeley in England first discovered the disease in 1846 (Chupp and Sherf, 1960) and since then it has been found in all parts of the world where the crop is grown intensively. The occurrence of the disease has been reported from Argentina, Australia, Canada, Chile, Denmark, France, Germany, Kenya, Netherland, New Zealand, Rhodesia, Spain, Tasmania, USA, Ukrain, Italy, Poland and Australia (Dixon,1981). In India it is prevalent in Indogangetic plains including Uttar Pradesh and Punjab (Bains and Dhaliwal, 1986).

6.1. Downy mildew of Sugarcane

Pathogen: Sugarcane downy mildew can be caused by four species:

    1)    Peronosclerospora sacchari
    2)    P. miscanthi
    3)    P. spontanea and
    4)    P. philippinensis

Major Host
Hosts in the Saccharum genus include: S. officinarum, S. robustum, S. spontaneum and S. edule.

Minor Host
Other hosts include Zea mays (maize), teosinte (Euchlaena mexicana), Sorghum halapense (Johnson grass), S. sudanense (Sudan grass), Tripsacum dactyloides (Gama grass), Sorghum bicolor (broom corn). Other studies suggest there are 18 species that are systemically infected in the sub-family Panicoideae; these include species of Andropogon, Bothriochloa, Eulalia, Schizachyrium and Sorghum (Bonde & Peterson 1981)

Geographic Distribution
The disease is restricted to the Pacific, South Asia and South East Asian regions viz Fiji, India, Indonesia, Japan, Papua New Guinea, Philippines, Taiwan and Thailand (Suma & Magarey 2000).

9.1 INTRODUCTION

Cluster bean is grown in India to a lesser extent than other beans. It is a commercial crop of arid and semi-arid regions. It is grown for its green pods that are used as vegetable and dry seeds. It is also grown as forage and green manure crop. Among leguminous crops it is comparatively hardier, drought resistant and cultivated on a large scale as a forage crop in dry regions because of its deep tap root system which enables it to recover from water stress. Some of the cultivars are used for extraction of gum called as guargum. The gum obtained from this crop is like a mucilaginous substance called galactomannan that is used in various industries particularly textiles, cosmetics, explosives and paper. Due to its colloidal nature, the gum acts as a stabilizer and thickener in food products,viz., ice cream, bakery mixes and salad dressings. The seeds of clusterbean contain about 30-33% gum in the endosperm. The gum in the seeds are galactomannan polysaccharides. The discovery of the galactomannan gum in the endosperm during 1948, led to its importance as an industrial crop. Today it is one of the significant foreign exchange earners of the country. Fresh pods contain 82.5% water, 9.9% carbohydrate, 3.7% protein, 0.2% fat, 2.3% fibre and 1.4% mineral matter. Cyamopsis senegalensis is the ancestor of guar. The largest growing state is Rajasthan (82%). Young plants of cluster bean contain hydrocyanic acid which causes toxicity to animals. It is an amide (asparagine and glutamine) producing legumes.

Ridge gourd or Ribbed gourd (Luffa acutangula Rox b. L) and Sponge gourd or Smooth gourd (Luffa cylindrica) have diploid chromosome number  2n=2x=26. Luffa has old world origin in Subtropical Asian region including India (Kalloo, 1993). These two species are inter-crossable. F1 plants generally, intermediate between the parents and showed various irregularities like, univalants, rings and chains of 4 chromosomes, chromatids bridges and fragments at metaphase and thus the species are not easily crossable and the F1 plants appear to be of not much practical value. The genus is monoecious annual vine, tendrils are branched, flowers are yellow, anthers are free and pistil has three placentas with many ovules and stigma are three and bilobate. Fruits oblong or cylindrical and rind becomes dry on maturity.

Bottle gourd (Lageneria siceraria) 2n=2x=22 is also known as white flowered gourd. Most important vegetable of ancient China.
 
Origin : According to De Candolle (1882) Bottle gourd has been found in wild form in South Africa and India. However, Cutler and Whitaker (1962) are of the view that probably it is indigenous to Tropical Africa on the basis of variability in seeds and fruits. This species appear to have been domesticated independently in Asia, Africa and the New world (Heiser, 1973).
 
Botany: It is monoecious, annual vine with soft pubescence. Leaves are cordate ovate to reniform-ovate, Flowers are white, solitary, open at night and has hairy ovary. Fruit shape is cylindrical, oval egg shaped, club shaped, round and other shapes also appeared.

Genetics of Important Traits

Bitterness: Single dominant gene (Path and Singh, 1950)

Fruit colour: Monogenically controlled (Kalloo, 1993)

Two major genes are involved for fruit shape (Path and Singh, 1950). Single gene for fruit colour involved (patchy v/s white) and reported by Path and Singh (1950). Monogenic recessive inheritance for andromonoecious sex form is reported by Singh et al. (1996). Hermaphrodite sex form is characterized by long corolla (3.5-4.5cm instead of 2.5-3.5cm in normal). In hermaphrodite condition fruits bears prominent blossom scar.  Long fruit conditioned by AA genotype and Round fruit is due to aa genotype where Partial dominance is reported (Kushwaha, 1996).

Sweet potato Ipomea batatas(L). Lam. is an asexually propagated vegetable. It is grown in most of the tropical and subtropical region of the earth. In USA production extended to temperate regions. Vines as well as roots are eaten or fed to live stock. It is the source of industrial starch and potential source of the alcohol. Among the major tuber crops cultivated in India sweet potato rank third after potato and cassava in area and production.

Origin: Available evidence suggests South Mexico through Central America and Northern South America as the probable center of origin. It is perennial but handled as annual. Its hardiness and drought tolerance are well recognized.

Family: Convolvulaceae, Chromosome number: 2n=90

It is the only known natural hexaploid morning glory. Most of the wild species are diploid (2n=30). Hybridization is restricted with in species because of its hexaploidy nature. Extensive variability with in species is observed. Tuber is the fleshy subterranean stem or shoot but in sweet potato tuber is a root, and hence it cannot be a tuber (common error). It is a perennial, and the storage root is capable of continued enlargement and does not mature in the sense of reaching some final size or stage of development. From the stand point of function, the root system consists of absorbing roots and fleshy storage roots.

Nutrients

The nutrients are chemical elements which are absorbed by the plants in more or less quantity to transform light energy into chemical energy and to keep up plant metabolism for the synthesis of organic materials. These materials constitute among other things, foods for humans and animals and a range of raw materials for various industrial uses. Feeding of plants with nutrients is termed as nutrition. Successful growth and production of the plants in general requires a proper supply of the 17 elements. These elements are regarded as essential to life in higher plants.

Horticultural plants are grown for their produce like fruit, vegetable, flower, medicinal component, spices etc. Therefore, these plants should be managed in such a way that human desires for the purpose of growing them are fully satisfied in terms of quality and quantity of produce. This demands direct manipulation of plant growth itself or plant environment through various inputs. In manipulation of plant development, training and pruning are important for which our knowledge about plant development and its phenology has to be complete. These practices are important in fruit crops.

Vegetable crops: A seed is borne on fruit and fruit is a mature ovary and ovary is a typical part of flower. Flower in angiosperm, consists of four parts these are calyx/sepal, corolla/petals, androecium/stamens and gynocium/pistil, outer whorl of flower is collectively referred to as calyx. The individual components of calyx are called as sepal. Petals are collectively referred to as corolla. Petal is a unit of second inner whorl after sepals. Stamen is part of flower bearing the male reproductive parts composed of anther and filaments. Pistil is part of flower bearing the female reproductive parts composed of stigma style and ovary.

Seed Production Techniques in Vegetable Crops

Share (%) of F₁ hybrids- Cabbage 85%, Watermelon 70%, Okra 23%, Tomato 80%, Chilli 80%, Cauliflower 50%. Among the Asian countries, India is the 2^nd largest production of hand pollinated hybrid seed in vegetables.

The planning of a garden is an art. It is said that a poet is born, and in that sense a garden architect is also born. But that does not mean that a garden architect has nothing to learn. On the contrary he should learn enough of geology, geography, garden history, styles of gardening, and above all should have a profound knowledge about plants. It is imperative to know at the outset what is meant by landscape gardening. A landscape may be defined as any area, either big or small, on which it is possible or desirable to mould view or a design, whereas landscape gardening may be described as the application of garden forms, methods, and materials with a view to improving the landscape. The art of designing is known as “landscape architecture,” although the older term landscape gardening” is also popular.

Before discussing the principles of gardening in detail, it will be worthwhile to make some useful suggestions. The first and the foremost thing are not to imitate another garden which has secured a prize in a competition. One has to develop one’s own design giving due consideration to the local conditions. One more mistake which is commonly made is to plant many more specimens than a garden can accommodate causing overcrowding. In a landscape garden any difference in levels has to be taken advantage of, but in a perfectly flat land it will be costly to create artificial undulations. In each garden the care should be at least one feature or there be a second these two should harmonize with each other. Before planning a design are must be sure for what purpose the garden is utility or beauty or both.

Annuals

Annuals or seassonals are the group of plants which complete their life cycle in one season or in one year. Annuals are commonly known as seasonal as they complete the process of life like germination, growth flowering and seed formation in one season and finally the plant without. Annuals are widely used for garden decoration, cut flower and pot plants. They are frequently grown as bedding plant and in rock garden on the sides of lily pool and in shrubberies.

Trees

A trees is a woody perennial plant with clear stem or trunk. Trees trend to be long leaved living up to several 100 year.

TREE- logical meaning of each letter

T - Temperature and micro-climate moderation.

R - Removal of air pollutant.

E- Erosion control.

E - Energy conservation.

If x and y are related, we can study degree of relationship between them which is called correlation.

Y = f(x)=a+bx where y is a dependent variable and x is an independent variable. If x is known, y can be known.

X = f(y). Here x is a dependent variable and y is an independent variable or auxiliary variable.

9.1 Introduction

The tests used to ascertain whether the differences between estimator and the parameter or between two estimators are real or due to chance are called tests of hypothesis or tests of significance. In other words, the procedures, which enable us to decide whether to accept or reject hypothesis, are called tests of hypothesis or tests of significance. The following terms are commonly used in testing of hypothesis

The wide range of climatic conditions in India provides a choice of various bulbous crops to grow them in different parts of country. The term bulbous includes a wide array of perennial plants that are grown from underground organs, including bulbs, corms, tubers and rhizomes. Any plant described as bulbous will normally have a swollen root or stem or even leaves underground. A large number of these plants producing attractive flowers are commercially grown now days. Normally bulbous plant has a three phases during a year growth, flowering and dormancy. Bulbous plants are grown commonly in beds, shrubbery, herbaceous border, grassy land and in pots and bowl. A brief description of some common bulbous crops is given below.

1. Amaryllis: Common name (CN): Belladonna lily, King or Star lily, Botanical name (BN): Amaryllis spp., Family (F): Amaryllidaceae, Origin (O): South Africa.

Amaryllis is an excellent bulbous plant with deciduous foliage. Leaves are produced after cessation of flowering. It is suitable for bedding, pot, window boxes, greenhouses, borders, etc. Flowers are sold in the market as cut flowers. The flowers are large, trumpet shaped and are borne in umbels having 3-7 florets in small flowered varieties whereas 2-4 florets of giant size in Dutch hybrids. Amaryllis is propagated by vegetative means. They are mostly propagated through bulbs. They are also commercially propagated through tissue culture. Important species are Amaryllis belladonna, A. angustifolia, A. leopolidii, A. moreliana, A. papilio, A. striata, A. miniata and A. traubii.

Definition: Bonsai is an art of growing dwarfed, ornamentally shaped trees or shrubs in shallow containers or trays. It’s an art that expresses in miniature form of a natural tree. The word Bonsai is a Japanese term which literally means “planted in a container”.

This art form is derived from an ancient Chinese horticultural practice, part of which was then redeveloped under the influence of Japanese Zen Buddhism. Thus, origin of bonsai culture is China. Though it was popularized by Japanese. The ultimate goal of growing a bonsai is to create a miniaturized but realistic representation of nature in the form of a tree. In Japan bonsai is not only a hobby but also act as status symbol.

Introduction

Gerbera is a herbaceous flower crop with leafless stalk and daisy like flowers. It is also known as Transvaal daisy. Gerbera is a popular cut flower grown throughout the world. It is ideally suited for flower beds, borders, pots and gardens.

In California and Florida, it is grown in outdoors and is becoming increasingly popular as potted plant and bedding plant, whereas in other parts of United States it is cultivated in greenhouses. Gerbera cultivation has emerged as a very important option to progressive farmers in many parts of India, especially in Maharashtra, Karnataka, North Eastern states, U.P. and Uttarakhand.

Genetics

The genus Gerbera belongs to family Asteraceae. Gerbera comprises about 70 species, which are of African and Asiatic origin. The basic chromosome number is n=25. G. jamesonii is a diploid species with somatic chromosome number 2n=50. Among the different species, G. jamesonii is the only species under cultivation.

Seed is defined as “Fertilized and ripened ovule, consisting of the plant embryo, varying amounts of stored food material and a protective outer seed coat”. It is one of the most vital and important inputs for increasing production of crops. Commercial flower seed production is an international business involving highly specialized growers. Demand of flower seed production increased due to recent advances in commercial production of bedding plants, plug production technology, increased area of gardening, flower growing in home gardens and cut flowers with highly viable seeds and very high percentage of uniform seedlings. It seems to have great scope for expansion in developing countries like India, especially under north Indian climate having favourable growing conditions, skilled and cheap labour.

The world germplasm contains more than 1500 different varieties of flowers and ornamental crops. Each species of flower grown for seed has its own specific time, culture, problem of pollination and harvesting and storage requirements. Growing flower from seed is an important component of commercial flower production and their uses in landscape gardening.

Shifts or changes in the abundance and types of weeds within agricultural systems are common. These shifts can occur for a number of reasons and may result from cultural, mechanical, or chemical weed management strategies. The right combination of weeds and relying too heavily on any one practice is often the most common cause. Some of the concepts associated with weed species shifts are discussed below.

A weed shift is the change in the composition or relative frequencies of weeds in a weed population (all individuals of a single species in a defined area) or community (all plant populations in a defined area) in response to natural or human-made environmental changes in an agricultural system. Weed shifts occur when weed management practices do not control an entire weed community or population. Some species or biotypes are killed by (or susceptible to) the weed management practice, others are not affected by the management practice (tolerant or resistant), and still others do not encounter the management practice (dormant at application).

Those species that are not controlled can grow, reproduce, and increase in the community; resulting in a weed shift. Any cultural, physiological, biological, or chemical practice that modifies the growing environment without controlling all species equally can result in a weed shift. Weed shift may be due to introduction of new species or change in relative proportion of members of the existing community. Latter is the most common.

A. Species shift: Change in density of one or more species in field

B. Biotype shift: Change in density of biotypes within a species. These shifts often found noticed since biotypes typically are similar in appearance. Herbicide resistantbiotypes are the most frequently studied.

Weed Management

The productivity of crops much depends on intercultural and weeding operation. The efficient management practices ultimately increases the yield level. The productivity is much dependent on various attributes starting from the variety, climate including human resource management and other factors known well to the farmers. It is estimated that nearly 30-50 per cent of the crop is lost due to weed menace in the agricultural fields. The farmers use various methods of weed control like cultural, mechanical, chemical and manual means. Encompassing all these control measures is known as integrated weed management.

Introduction

The search for order in the location and size of settlements continues. Certain geographers examined the size of distribution of settlements and described in graphical form the relationship between the number and size of settlements. Their methods were radically different in that they were not deterministic, rather than making a set of assumptions, deriving a theory and testing it against reality, they observed the size and number of settlements in various countries and noted a common characteristic, which was called the rank size rule. Having once observed this order in the real world, they then sought to explain it. A relationship which is observed on several occasions is called an empirical regularity. The rank size rule is one such empirical regularity.

The rank size rule was first observed by Auerbach in 1913 but was proposed and popularized by G.K. Zipf in his book “Human Behaviour and the Principle of Least Effort”. Since then, many writers have attempted to explain it but the basic aim has always remained the same: to find a graphical description to the size distribution of cities which would apply to the situation prevailing in many countries.

Rank Size Rule: Theoretical Base and Concept

Rank size rule is a theory describing numerical distribution of settlement, which recognises an empirical regularity whereby the product obtained by multiplying a city’s rank by its size is equal to a constant, the population of the country’s largest city such that for a given settlement system

Thomas Robert Malthus enunciated his views about population in his famous book, Essay on the Principle of Population as it affects the Future Improvement of Society, published in 1798. Malthus revolted against the prevailing optimism shared by his father and Godwin that a perfect state could be attained if human restraints could be removed.

Malthus’ objection was that the pressure of increasing population on the food supply would destroy perfection and there would be misery in the world. Malthus was severely criticised for his pessimistic views which led him to travel on the continent of Europe to gather data in support of his thesis. He incorporated his researches in the second edition of his Essay published in 1803.

The Malthusian theory of population is the most well-known theory on population in economics. Malthus pointed out that an accelerated increase in population would outweigh the increase in food production. This would have an adverse impact on the development of an economy. The Malthusian theory explains the relationship between the growth in food supply and in population. It states that population increase faster than food supply and if unchecked leads to vice or misery. This theory is explained in the following propositions

1. Introduction

Agricultural mechanization refers to usage of any improved tool, implement and machine by the farm workers to improve the efficiency of any operation to increase productivity. It also helps to reduce drudgery or stress which adversely affects human mental faculties leading to errors, imprecision and hazards and eventually loss of efficiency if done manually. In developed countries, however, mechanization is synonymous to automation. There is scope to mechanize every operation of crop production, post harvest and agro-processing.

18.1. What?

The basic objective of sowing is to place the seed in rows at the desired depth, to maintain proper spacing between seed to seed, cover the seeds with soil and provide proper compaction over the seed if required. Precise sowing/planting helps in better crop stand. This helps to achieve optimum yields. Traditional sowing methods include broadcasting manually, opening furrows by a country plough and dropping seeds by hand (i.e.) dibbling. In the present day, improved seed-cum-fertilizer drills are used for sowing and fertilizer application. These are provided with seed and fertilizer boxes, metering mechanism, furrow openers, covering devices, frame, ground drive system and controls for variation of seed and fertilizer rates.

18.2. Types of sowing/planting equipment

Sowing equipment include seeders and transplanters. Various types of sowing equipment, viz., manually operated, animal drawn, power operated and tractor drawn are used throughout India.

18.2.1. Seed drills

Seeders are available for sowing seeds of various crops. Some seeders have been designed with adjustable metering mechanism which makes them versatile for sowing two or three kinds of seeds. For example, a multicrop planter developed by CIAE is used for sowing garlic, maize, moong, peas and groundnut. Similarly, the institute has developed a small seed sowing drill which is used for sowing small seeds such as bajra, rapeseed and mustard.

21.1. What?

Harvest is the process of gathering the end produce from mature crops in the fields. Harvest marks the end of the growing season, or the growing cycle for a particular crop. Harvesting is the most labour-intensive activity. Moreover, timely harvest before shattering of the produce or before rain assumes significance. As adjacent fields sown at the same time come to harvest simultaneously, farmers face great problem in getting manual labour for harvesting and cleaning their produce. To overcome these difficulties, different types of harvesters have been developed from time and again to suit different crops, situation and conditions.

21.2. Harvester and reaper

Harvesters are used to cut the crop after they mature. In such cases, threshing is to be done separately. Harvesters are available for a wide range of crops belonging to cereals, pulses, millets, oilseeds, fruits and plantation crops. Reapers are used to harvest crops such as rice, wheat, soybean, mustard, rapeseed, safflower and other thin stemmed crops. Reapers are operated using power tiller.

Sustainable sericulture has to take more care about retaining or rebuilding soil quality and health, since it is very high drain on the nutrient content of soil. Sustainability should an evolution criterion in the process of identifying, screening and adopting techno-biological solutions to the sericultural problems. Greater attention should be paid to learn from the indigenous knowledge. In many of the government-sponsored programmes sericulture has been regarded as one of the essential tool for the rural development in the country. As the activities in the sericulture are capable enough to engage the households completely throughout the year and is ideally suited for improving the socioeconomic standards of the rural poor and has often been utilized under various employment programmes in India. As a result, sericulture is being intensively promoted in traditional states like Karnataka, Tamil Nadu, Andhra Pradesh, West Bengal and J & K.

This chapter tries to find out the constraints in adoption of sericulture as subsidiary enterprise the farmers in the Poonch district of Jammu & Kashmir. Since sericulture is not a major activity in the district and farmers never reluctant to cultivate mulberry in their land and allow only dry land for plantation of mulberry and hardly take care thereafter. Under such circumstances the mulberry grows with lesser leaves production and farmers always faced acute shortage of mulberry leaves during silkworm rearing and they did not get the expected return out of the sericulture. Land, water, proper training of mulberry plants, application of fertilizers guarantee high production and productivity over a wide range in the same areas would qualify to be called as sustainable sericulture system in dry/hilly areas. Besides, other components of technology that can ensure sustainability are soil and water conservation, pests control etc.

Introduction

Plant Genetic Resources (PGR) are uniquely placed within the overall ambit of biodiversity and play an important role in providing food, fuel, clothing, medicine and shelter for the whole mankind. The value of plant genetic resources or the plant germplasm can be visualized from the fact that Sir Joseph Banks, the Director of Kew Botanical Gardens accompanied Captain Cook on a plant collecting voyage. Plant genetic resources are going to occupy the centre stage in plant breeding and seed industry development in India as will be the case with other countries. However, despite the great importance of plant genetic resources in crop improvement programmes, there is ever increasing threat to the PGR due to degradation of their habitats, changes in ecology, cropping systems, modernization of agriculture, rapid replacement of locally adapted indigenous cultivars by modern high yielding varieties and the effect of massive urbanization. This calls for a sustained and scientific management of plant genetic resources. The issue of PGR management remains basically the same whether we are dealing with field crops, vegetable crops or perennials with slight changes in specific cases. For an effective management of PGR, all the CGIAR funded international agricultural research centres have independent units/divisions on PGR management. IPGRI is coordinating and strengthening the PGR management programmes at the international level. In India, National Bureau of Plant Genetic Resources, New Delhi is the nodal organization on PGR management. This article shall deal with the core components of PGR management in vegetable crops.

Phenotypic Diversity

Phenotypic diversity measures the portion of genetic diversity which is expressed phenotypically. So it varies with the character under study and the genetic background and the environment in which it is measured. The measures of genetic diversity based on variance of quantitative traits may be unreliable indicators of diversity in a population at the level of individual gene. But diversity at the molecular level (isozymes, RFLPs) may be a reasonable estimate of phenotypic diversity. The degree of differentiation is related to several biological attributes such as breeding system, mode of pollination and seed dispersal, life history, geographical range, successional stages, etc. The outbreeding populations are much less differentiated whereas the selfers or apomictic are strongly differentiated. Populations of outbreeders contain different alleles especially the rare alleles which contribute little to the diversity. Inbreeders should have greater interpopulations diversity and less intrapopulation diversity than the comparable outbreeders. Further, inbreeders are more prone to show an even distribution of their genetic diversity among populations and this makes their optimum sampling more difficult and any evidence of the geographic pattern of this diversity levels would greatly improve sampling efficiency but geographical and environmental factors rarely explain more than 50% variation.

Plant genetic resources are the most valuable and essential basic raw material to meet the current and future need of crop improvement programme. A wider genetic base assume the priority in plant breeding research aimed as developing new varieties for increased crop production. PGR for food and agriculture are a reservoir of genetic adoptability, which act as buffer against environmental changes and economical challenges. The erosion of these resources results in a severe threat to the world long term food securities. The fundamental objective of the genetic resource conservation is the maintenance of genetic diversity within each of the species. In general PGR include all species which contribute to people by providing food, medicine, feed, fiber etc. PGR is our heritage which needs conservation for prosperity.

Genetic resources management is a complex process starting from the identification of a target gene pool for conservation to the use of genetic resources. Many of these activities not only generate but also require geo-referenced data (Spatial data). Analysis of these data can lead to a greater understanding of the eco-geographic representation of existing collections, increasing the efficiency of conserving and managing genetic resources and broadening our understanding of the distribution of genetic diversity. Genetic resource databases could potentially serve as an information resource to a broader scientific community, providing relatively independent global data sets to meet the unique needs of researcher. GIS can merge genetic diversity information with other georeferenced data such as population density, climate, topography and soils, adding value to genetic resources. GIS analysis can help develop conservation strategies, monitor genetic diversity, select potential collecting sites, design in situ reserves and enhance genetic resources use. Currently, GIS use is constrained by limited georeferenced information.

Paratition Value

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

MOMENTS

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

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

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

SKEWNESS

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

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

There are two types of skewness

(i) Positive Skewness (ii) Negative Skewness

KURTOSIS

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

Types of Kurtosis

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

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

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

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

1. SEED MATURITY

Harvesting should be done after the attainment of physiological maturity, when the seeds reached complete maturity to avoid harvesting of immature and ill-filled seeds.

1.1. Physiological maturity

It is the stage of accumulation of maximum drymatter within the seeds. It is expressed by maximum seed weight, germination and vigour potential. The moisture content of the seed at this stage is around 25-30% depending up on the species.

1.2. Harvestable maturity

The physiological maturity is represented to a seed and this maturity will not be the same for all the seeds of a single plant / population, due to continuous differential flowering habit. Hence, the stage of attainment of physiological maturity by 80% of the population is considered as the harvestable maturity stage. The moisture content of the seed will be lesser than the physiological maturity stage (18-20%).

1. VARIETY

Variety is a seed/crop which suit the prevailing agroclimatic conditions, high yielding and possessing desirable attributes such as disease resistance, earliness and grain quality. Similarly, the seed should be pure, appropriate classes, and obtained from an authorised official agency.

1. BASIC NUCLEUS SEED

The seed of the notified variety collected from the evolving institute with all the passport information is considered as basic nucleus seed. This seed is sown in prepared healthy field with more row to row and plant to plant distance than the normal recommendation at required isolation distance. Prescribed dose of fertilizer, irrigation and required plant protection measures are provided.

Off types and diseases plants are rogued out at seedling, before flowering, flowering and at physiological maturity stages. Plants are marked with contrast color thread and observed regularly. Marked plants are harvested separately and its produce is used as source seed for production of nucleus seed for next year. Produce of unmarked plants are used as nucleus seed for production of breeders seed. Harvesting threshing and drying are done without reducing physical and genetic purity. The discolored and diseased seeds are removed. The pure seed obtained is the nucleus seed for seed multiplication chain

1. INTRODUCTION

Indian population is estimated to increase to about 1400 million by 2025. Consequently, India’s requirements for food grains and other food products to feed the increasing population will continue to rise. The food grain requirements are estimated at 350 to 370 million tonnes by 2025. The demand pattern for agricultural commodities for the domestic market will also shift as a result of increasing incomes and faster urbanization. Compared to 26% increase in 1991, the urban population is projected to increase by 42% in 2020. For competing in the global market, the product pattern will shift to high value commodities like fruits, vegetables, floriculture, dairy products, meat and marine products. In such a future scenario, it is necessary to increase agricultural production through improved cropping system, judicious use of agro-inputs and wide use of modern agricultural technology. It is also important to augment and streamline the existing marketing system including handling, transportation, storage, processing and distribution.

1. HETEROSIS

1.1. Definition

Heterosis or hybrid vigor or outbreeding enhancement, is the increased function of any biological quality in a hybrid offspring. It is the occurrence of a genetically superior offspring from mixing the genes of its parents.

1.2. Inbreeding depression

Inbreeding depression is the reduced fitness in a given population as a result of breeding of related individuals. In general, the higher the genetic variation within a breeding population, the less likely it is to suffer from inbreeding depression.

1. DEFINITION

Micropropagation is the growing of plants from meristematic tissue or somatic cells of superior plants on nutrient suitable media under controlled aseptic physical conditions.

1. INTRODUCTION

Field run seeds obtained from the seed production field posses high moisture and physical contaminants like trash and other inert materials (sand, stones, soil etc.,), diseased and pest damaged seeds, other crop seeds, weed seeds, deteriorated and damaged seeds, off-size and ill filled seeds, plant remnants etc. Seed processing is must to dry the seeds to safe moisture level, remove unwanted and inert materials as detailed above.

Seed qualities such as vigour and viability are improved by certain physical characteristics of the seed i.e., shape, size, large, denser and sound seed, etc. So, if grading is done to obtain a particular range of size, shape, length and density of the seeds, the quality of the lot is upgraded.

Seed processing refers to all the steps necessary for preparation of harvested seed for marketing namely handling, drying, shelling, preconditioning, cleaning, size grading, treating and packaging.

Any new variety produced by the Scientist has to be multiplied to many times to meet the needs of the farmers. In order to ensure the availability of quality seeds, Government of India have enacted Seed Act 1966 and Seed Rules, 1968. The Seed (Control) order 1983 was promulgated under essential commodities act, 1955 in order to ensure the production, marketing and distribution of the seeds.

1. SEED ACT 1966

The objective of Seed Act is for regulating the quality of certain notified kind / varieties of seeds for sale and for matters connected therewith. The Seed Act passed by the Indian Parliament in 1966 was designed to create a ‘climate’ in which the seeds man could operate effectively and to make good quality seed available to cultivators. Seed Rules under the Act were notified in September 1968 and the act was implemented in October 1969. This act extent to the whole of India and it has 25 sections.

1. SEED CERTIFICATION

Seed Certification is a legally sanctioned system for quality control on seed multiplication and production. It involves field inspection, pre and post control tests and seed quality tests.

1.1. Phases of Seed Certification

Certification shall be completed in six broad phases listed under

1. UNIT OF CERTIFICATION

The entire area planted under seed production programme by an individual constitutes an unit, provided;

1. All the seed production programme is to produce seed of one category and one variety.
2. Area does not exceed 10 hectares and scattered fields constituting one unit (10 ha) should not be separated by more than 50 metres distance (Table 1).
3. The crop of the entire area is more or less of the same growth stage. The seed crop is grown as sole crop and it is not heavily and uniformly lodged.

1. SEED STORAGE

Is the maintenance of high seed germination and vigour from harvest until planting.

1.1. Importance of seed storage

Seed storage is important to get adequate plant stands in addition to healthy and vigorous plants.