eChapters

(I) Digestion of Feed

In feed, carbohydrate is the main nutritive substance which is in the form of insoluble large particles. For intestinal absorption by blood and lymph, it is necessary to be digested as small and simple particles. For example, carbohydrate found in the form of starch or glycogen is not absorbed as such and is only absorbed when it is converted into the simple soluble monosaccharide form. Similarly, proteins present in the feed are also not absorbed untill they are digested into simple forms of aminoacids (Fig. 27, Fig. 28, Fig. 29, Fig. 30). Piglets are exceptions, as the newly born piglets obtain colostrum from their mother. Colostrum is rich in gamma immunoglobulins. This immunoglobulin is abosrbed as such without digestion by pinocytosis. It gives immunity to save the new piglets from many diseases. For this reason, colostrum suckling is necessary for new piglets. The process of pinocytosis occur only few days after birth and it  stops after some time. Fat occurs in the form of triglycerides in the feed. For absorption of the fat, it is necessary to be converted into its simple forms such as glycerol, free fatty acids or in the form of monoglycerides.

(I)  Deficiency Diseases

Mineral and vitamins, in adequate quantities, are essential in the diet of all animals. Many diseases occur due to deficiency of mineral and vitamins. Mineral and vitamins are more necessary in pigs due to their higher growth rate. It is normally seen that when pigs are reared on self made rations, they suffer more with the deficiency of one or more mineral and vitamins. Thus, it is necessary to introduce extra mineral and vitamins in the pig ration. If it is not done, its growth rate and body weight do not increase in proper ratio. The excess and deficiency of one mineral depends on quantities of other minerals present in the ration. It is frequently seen that pigs suffer from deficiency of more than one mineral and vitamin but some time pigs suffer from deficiency of one substance and excess of the other substance, so a balanced ration- with appropriate proportions of various mineral and vitamins- is necessary. Many times it is seen that some infectious diseases increase the necessity of mineral and vitamins in the body. This may cause deficiency of mineral and vitamins in the body and the animal may not recoup.

Following are the description of these symptoms and their prevention.

Pig Production on Scavenging

Pig farming has become a profitable enterprise since it possesses many economic traits e.g. high prolificacy, faster growth rate, shorter generation interval, low cost of rearing and high dressing percentage with better feed conversion efficiency. Pigs give quick return, convert inedible feed into valuable products, require less labor, adopt most types of farming systems, aid soil fertility, supplement other enterprises, etc. It is still considered as backward profession and unorganized rearing largely dominates the sector, and it is primarily in the hand of poor, landless and weaker section of society.

(I)  Slaughter and Preservation of Swine

Clean meat production from animals has been a difficult task since ancient times. Now it has become easier due to the joint efforts of Veterinarians and progressive animal owners. For clean meat production, with healthy animals, it is essential that care is given to their better management, better breeds, good ration and arrangements for preventing diseases are made. Meat from diseased animals is of inferior quality and unfit for human consumption.

            Meat is a very useful edible material, which is used for its high nutritive value with a good taste. Due to these nutritive elements, many microorganisms come in contact with the meat and they may contaminate it and change its natural structure and composition. As a result it produces many types of toxic and bad odour substances.

            Meat has an important place amongst human foods. Meat has many pecularities for which it is used in many parts of the world and by people of different religions. Many people prefer meat because of its better taste and/or odour. Often, it is observed that people consuming meat do not prefer vegetarian foods. The active consumer always gives more importance to the nutritive elements in meat. And at the time of bying meat, they prefer taking complete meat.  Allmost in all countries of the world, few selected and common animal species are slaughtered for meat production.

Swine Marketing

The animal population in India is nearly 14 millions which is increasing day by day. The importance of animals in Indian Economy cannot be neglected. The economic benefit from animals is 26% of the total benefit from agriculture. Agricultural farming is not possible without animals. In agricultural profession, animals have an important role. In our country, crores of small and marginal farmers and agricultural labourers depend for their life on animals for their livelihood. Poor animal wealth is not a good symptom for a country.

Till today the work which is done on animal wealth by economists and marketing specialists is only limited. Economic and marketing studies on meat producing animals in our country is very less. Pigs are normally reared for meat purposes. Pigs are mostly untouched from this type of research on economic and marketing aspects. Pig population in our country is nearly 12 millions, which is 2.5% of total animal population in India.

Due to lack of studies, it is not possible to give any statement about correct situation of marketing and capacity of pigs.

Commonly used terms in swine husbandary

Angier, Natalie (2009-11-09). “Pigs Prove to Be Smart, if Not Vain”. The New York Times (New York, New York, US: The New York Times Company).

Anonymous 2002-03. Annual Report of Animal Husbandry and Veterinary Department, Directorate of Animal. Husbandry and Veterinary Department, Government of Mizoram, Pp 8

Broom, Donald M.; Hilana Sena, Kiera L. Moynihan (2009-11). “Pigs learn what a mirror image represents and use it to obtain information”. Animal Behaviour 78 (5): 1037-1041.

Burkholder JoAnn; Bob Libra, Peter Weyer, Susan Heathcote, Dana Kolpin, Peter S. Thorne, Michael Wichman (2007) Impacts of Waste from Concentrated Animal Feeding Operations on Water Quality. Environ Health Perspectives. 115:308-312.

Chandrashekhar Sahukar. (2000). Piggery India Year Book, pp. 343-347.

Christianson, L.L, Bane D.P, Curtis S.E, Hall W.F, Muehling A.J, and Riskowski G.L. 1989. Swine Care Handbook for Pork Producers Using Environmentally Controlled Housing. Des Moines: National Pork Producers Council.

Crucik Shank, R et al (1965). Medical Microbiology, ELBS, London.

Curtis, S.E., et al. 1988. Guide for the Care and Use of Agricultural Animals in Agricultural Research and Teaching. Champaign III, Consortium for Developing a Guide for the Care and Use of Agricultural Animals in Agricultural Research and Teaching.

Dalton, C. and. Kilgour R.1984. Livestock Behaviour; A Practical Guide. Granada Publishing, Lt., Frogmore, St. albans, Herts, U.K.

Daszak et al (2000). Emerging Infectious Diseases of Wildlife — Threats to Biodiversity and Human Health. Science Vol 287 pp 443-449

Delgado, C., Rosegrant, M., Steinfeld, H., Ehui, S., Courbois, C., 1999. Livestock to 2020. The next food revolution. Food, Agriculture, and the Environment Discussion Paper28. IFPRI, FAO, ILRI

DeShazer, J.A and ONil erhults D.G.1982. Energy Demand in Livestock Production. Livestock Environment, Proceedings of 2nd International Livestock Environment Symposium. American Society of Agricultural Engineers, St. Joseph, MO.

Donham K. (1998). “The impact of industrial swine production on human health”. In Thu K, Durrenberger E. Pigs, Profits, and Rural Communities. Albany, NY: State University of New York Press. pp. 73-83.

Eastman, Wilbur F. The Canning, Freezing, Curing & Smoking of Meat, Fish & Game, Garden Way Publishing, 1975, ISBN 0-88266-045-4

Embog, H.D. et at (1996). How the Danish surveillance system for Salmonella has influenced the microbiological quality of swine carcase meat. Proc. Int. Pig. Vet. Soc.14:714.

FAO (1983). Integrated crops and livestock in West Africa. Animal Production and Health paper. Rome, No. 41. Foodand Agriculture Organisation of the United Nation.

FAO (1998a). Farm Animal Genetic Resources: Biodiversity for food and agriculture. Food and Agriculture Organisation of the United Nation.

FAO (1998b). Local animal breeds still threatened by extinction, No. 4. Food and Agriculture Organisation of the United Nation.

FAO (2001). Bulletin of Statistics. Vol.2, No.1. Food and Agriculture Organisation of the United Nations.

INTRODUCTION

Modern agriculture relies more on monoculture, which is highly energy intensive and has a narrow genetic base. This has disturbed the normal ecosystem and sometime results in disease epidemics. The problem becomes much more serious in case of soil borne pathogens, as soil medium is a highly complex living system and is also the habitat of many micro organisms including the pathogens whose activities are influenced by interaction in it. Many serious plant diseases are associated with soil-borne plant pathogens, which cause root rot, crown rot, damping off, blights, fruit decay and wilts in field and horticultural crops. Soil borne plant pathogens, which are most tricky and challenging ones, cause sustainable economic loss. Many important fungal pathogens reside in the soil and infect roots of crops often causing significant yield losses. Soil-borne diseases result from a reduction in biodiversity of soil organisms.

INTRODUCTION

Rhizoctonia solani Kuhn (teleomorph: Thanatephorus cucumeris (Frank) Donk is cosmopolitan in soils. It is a destructive plant pathogen with an almost unlimited host range. The fungus inhabits in soils and causes damping-off of seedlings, root, crown and stem rots, and occasionally foliar blight (Baker, 1970). R. solani is an important symbiont with the saprophytic seedling stage (protocorm) of many orchids (Warcup, 1985). It aggressively colonizes organic matter and is one of the fastest growing fungi. According to available information, the isolates of R. solani possess the following-characteristics (Plate 2.1).

INTRODUCTION

All plant species grown on this universe are attacked by insect-pests and diseases, resulting huge yield losses in agriculturally important species. Among diseases, extensive yield losses occurred due to soil borne fungal plant pathogens. Soil borne fungal pathogens infect roots or stem bases, their dispersal and survival stages are primarily confined to the soil. Although many soil pathogens may also produce air or water dispersed spores which results in long distance dispersal. Soil borne fungal diseases are specifically those diseases where the soil borne fungi has the capacity to survive in soil for long periods in the absence of their hosts, or survive in the soil outside of seed or host residues, but infection and symptom expression are confined to the subterranean organs of the plant. Soil borne fungi may be divided into two classes: i) The  soil inhabiting fungus which is characterized by its ability to survive indefinitely as saprophyte (e.g. Rhizoctonia, Sclerotium) and ii) The soil invading or root inhabiting fungus which is characterized by an expanding parasitic phase and a declining saprophytic phase after  the hosts death.

INTRODUCTION
 
The form genus Sclerotium was described by Saccardo (Saccardo, 1913) to include fungi that produce sclerotia and had sterile mycelia. Several fungi were inc1uded in this genus, and all were characterized by production of small, dark brown or black spherical sclerotia that were internally differentiated into a rind, cortex and medulla. Several plant pathogenic fungi with this sclerotial type and with no known sexual or conidial state were placed in the genus Sclerotium. However, as the teleomorphic states were discovered, affinities to the Basidiomycotina (Punja, 1988) or Ascomycotina (Krause and Webster, 1972) were established for some members of the form genus.

INTRODUCTION

Biological control involves the suppression of pests/organisms with other organisms.  It is an eco-friendly method for management of plant pathogens which can be done exploiting the fungi (Ampelomyces, Trichoderma, Coniothyrium, Candida etc.) or bacteria (Agrobacterium, Bacillus, Pseudomonas and Streptomyces) from rhizosphere,  as well as phylloplane and endophytes (Jayaraman and Verma, 2002). The rhizosphere microfloras are predominantly composed of gram negative pseudomonads.  The fluorescent pseudomonads constitute a large proportion of the rhizosphere microflora presumably due to their nutritional variability being able to use a large number of organic substances (Stolp and Gadkari, 1981). However earlier workers used fluorescent pseudomonads extensively they now prefer Bacillus sp. due to their spore forming ability and heat tolerance which make its formulation easier.

INTRODUCTION

Throughout the history of agriculture, humans have struggled to reduce the adverse effects of plant disease on their crops. Early agriculturalists realized the benefits of cultural practices such as crop rotation and the use of organic soil amendments in promoting plant productivity. It is now well established that many of these effects are achieved by promoting the natural microbiological processes that keep plant disease in check. Cultural practices were mainstays of traditional agricultural systems and still provide the primary approaches for management of many soilborne diseases today. For example, disease suppressive soils, into which pathogen(s) can be introduced without causing the expected levels of disease severity, can result from alterations in cropping patterns or other cultural practices. Recently,

INTRODUCTION

Wheat has served as a source of staple food to the mankind since times immemorial. The production of wheat in India got a fillip after green revolution. Wheat production in India has increased by over ten times in the past five decades and India has become the second largest wheat producer in the world. Today, wheat plays an increasingly important role in the management of India’s food economy (Gandhi, et al., 2001). Wheat, primarily the winter cereal of Indo-Gangetic plain, is a major contributor to the agricultural economy of India, occupying nearly 25.9 m ha area with 71.8-mt production (Anon., 2003).

India is also second most populous country with one billion people. Demographers indicate that by 2012 India’s population will reach 1.2 billion. With this ever increasing population, there is also an increase in the demand for food grains. Depending on the rate and nature of economic growth and given the population growth rate about 4 or more per cent, annual rate of growth in the demand for wheat is likely to increase in the near future.

INTRODUCTION

In India, temperate fruits are grown successfully at locations above 3000 feet mean sea level in hilly areas of Himachal Pradesh, Jammu and Kashmir, Uttranchal, Sikkim, parts of North Eastern states like Assam, Arunachal Pradesh, Nagaland, Meghalaya etc. Mount Abu hills of Rajsthan and Nilgiris of Tamil Nadu also provide suitable agro-climatic conditions for growing some temperate fruits. Apart from apple; pear, peach, plum, apricot, cherry, almond and walnut are major temperate fruits being grown over 3.38 lakh hectares of area and play pivotal role in the economy of hilly farmers whose land is not otherwise considered suitable for traditional agriculture. They contribute about 11.5 percent of total area under fruits in the country, yet production is only 5 percent of the total. Incidence of many fungal, bacterial and viral diseases in these fruit crops is a major impediment in their successful cultivation and soil borne pathogens are of foremost importance and are responsible for premature death of the trees in the orchards. Amongst these, white root rot, collar rot, seedling blight, crown gall, hairy root are the major constraints which can cause as high as 40 percent damage in certain situations (Sharma and Sharma, 2001). Threat from the replant problem is causing concern due to its negative effect on the establishment of replanted sites due to soil sickness.

INTRODUCTION

‘Wilting’ is a broad terminology used by Plant Protection Scientists.  Any disturbance or damage to the normal physiology of the plant leads to ‘wilting’ of plants.  Wilting in cotton is attributed to many factors and it is necessary to single out the actual cause for wilting before suggesting any remedial measure (Kannan, 1991).
Wilting in cotton could be due to any one or more factors as indicated below:

INTRODUCTION

The fine feeder roots of many vascular plants are invaded by specific nonpathogenic fungi forming a distinct morphological unit known as mycorrhiza (In Greek, Mykes mean mushroom or fungus, rhiza mean root). Physiologically mycorrhiza represents a case of symbiosis.

The term mycorrhizae were coined by a German botanist Albert Bernard Frank in 1885 which literally mean “fungus-roots”.  Mycorrhizal fungi form a symbiotic association with agricultural and horticultural crops in addition to certain tropical tree species.
Mycorrhizal fungi are broadly classified in to two groups:
1) Ectomycorrhizae  
2) Endomycorrhizae.

INTRODUCTION

Burgeoning human population and its elevated living standard have greatly demanded more agricultural production. But unfortunately agricultural crops suffer deadly due to many biotic and abiotic stresses. Of biotic stresses, phytonematodes, the hidden enemies of crops are real threat to successful and profitable cultivation of agricultural crops (Plate. 11.1). These, endoparasitic nematodes, Meloidogyne spp. and Heterodera spp., are mainly dreadful causing wrecking havoc to agricultural scenario. Chemical control of these, tiny parasites created residue, resistance, resurgence, hazardous and pollution problems to the growers as well as soil and atmospheric environment. To overcome these hazards, efforts are being made to go for non-chemicals means of nematodes management strategies in crops. Hence, a research work carried out on management of these endoparasitic nemas particularly Meloidogyne spp. and Heterodera spp., through non-chemical methods is reviewed in subsequent status.

INTRODUCTION

In arid and semi-arid regions of India, besides weather aberrations, diseases caused by certain soil-borne pathogens are responsible for low productivity of agricultural crops. In addition to losses caused in annual crops, occurrence of these diseases in forestry takes away a major share. Because of the requirement for free water, diseases of aerial plant parts are much less common than those involving roots when plants are grown in dry regions where humidities are low and rains are infrequent and/or of short durations. Under these conditions, pathogens like Macrophomina phaseolina, Ganoderma lucidum, Cylindrocarpon lichenicola, Neocosmospora vasinfectum, Sclrotium rolfii and species of Fusarium (F. oxysporum, F. solani, F. equiseti, etc.) cause root rots and wilts in many commercially valuable and perennial plants.
Certain agro-climatic factors are attributed for the development of few specific diseases caused by soil-borne plant pathogens. Low organic matter, small microbial population coupled with poor moisture retention capacity of soil favour survival and multiplication of soil-borne pathogens (Fig. 12.1).

INTRODUCTION

Fungi naturally present in soil and rhizosphere of various crops serve as potential biological control agents of various plant pathogens. Species of fungi occurring in the genus Trichoderma have gained significant importance for use as agents for control of several diseases of cultivated crops. The last decade has witnessed a tremendous break-through in the research efforts on biological control of plant diseases in India especially by using species of Trichoderma and Gliocladium. Several economically important plant diseases of a variety of crops were effectively managed by using Trichoderma based biofungicides.

The work on biocontrol of pigeonpea wilt by Bacillus subtilis by Dr. R S Vasudeva and his associates, published as a series of papers in Annals of Applied Biology during 1950 to 1965 can be considered as a starting point for Indian work on biological control of plant pathogens (Mukhopadhyay, 1994).

INTRODUCTION

The genus Pratylenchus was established in 1936. It has a cosmopolitan distribution prevalent in temperate, sub-tropical and tropical regions. The species of Pratylenchus are popularly known as lesion nematode or meadow nematode. They are migratory endoparasites. Various pulse crops are damaged by them. P. thornei attacks chickpea,  P.zeae on mungbean (Walia and Seshadri, 1986); P. mulchandani on urdbean (Nanad Kumar et al., 1969) and Pratylenchus sp.on lentil (Mishra and Gaur, 1980) and cowpea (Aung and Prot, 1990).
Besides pulses species of Pratylenchus attack a number of other crops also. The infested plants exhibit various types of symptoms and results in heavy yield losses. Investigations have been made on various aspects of host-nematode relationship, distribution, host range, yield losses, biology, life cycle, disease cycle, interaction with other microorganism and management through cultural, physical, chemical, biological methods and host resistance.

INTRODUCTION

Soil-borne pathogens cause heavy losses to most agricultural crops. Repeated planting of a crop in the same piece of land results in a high inoculum build-up, which forces the farmers either to change the crop or the land. Thus, the search for new, effective, inexpensive and non-hazardous methods for the control of soil-borne diseases is a continuous one. Over the years, efforts have been made to manage the soil-borne pathogens by employing fumigants, chemical pesticides, biological control agents, different type of soil amendments and also by causing modifications in different cultural practices. But, pathogen control is often hampered by the fact that both the inoculum of the pathogens and the lethal agents applied to the soil are affected by the soil’s physical, chemical and biological environment. Keeping in view the bottlenecks with different methods of management of soil-borne pathogens; harnessing of solar energy i.e. soil solarization is an effective method to control soil-borne pathogens.

INTRODUCTION

Many economically important diseases are caused by Phytophthora spp. There are as many as 60 described Phytophthora species, most of which are primary invaders of plant tissues with limited saprophytic ability. Some important diseases with respect to symptoms, etiology and management have been described in this chapter as given below.

INTRODUCTION

Plants are susceptible to different types of pathogens, which are responsible for production of varied symptoms and causing losses. In the absence of the crops pathogens perpetuates in different manners and survival in the soil is one of the most important amongst these. Because of the constant presence of the pathogen in the soil, these become more destructive. These may reduce the plant growth, results in rotting of different plant parts, reduce yield or may cause the death of the plant. The destructiveness of soil borne pathogen increases because of the ability to survive in the soil as dormant structures for several years. Efficient control of soil borne diseases is thus difficult but can be achieved by employing various disease management practices in an integrated manner (Verma and Varma, 1992; Gupta, 1996, Gupta and Sharma, 1999).

1. Introduction

Fruits and vegetables represent highly perishable items of agriculture, mainly because of their high water content in fresh form. Their production, yield and management under agriculture is dealt essentially under horticulture. They abound in species and varieties in different geographic regions of the world, influenced by the agro-climatic conditions. Some are endemic and confined to certain geographic regions only. Accordingly, they may be tropical, sub-tropical or temperate, depending on their requirements of temperature for growth and yield.

1. Introduction

Vegetables and fruits are the next in demand for human consumption after rice and wheat, in all parts of the globe. Fresh fruits & vegetables and their value added products are increasing in popularity day by day almost in all the countries, because of their richness in dietary fibre, minerals & vitamin contents and for their medicinal properties. Maintaining agricultural produce quality and its evaluation are thus naturally important. Decisions concerning maturity and ripeness of fruits and vegetables are based mostly on visual inspections, which are subjective in nature. The quality of fruits and vegetables is mostly decided on the basis of size, shape, colour, gloss, flavour, firmness, texture, taste and freedom from external as well as internal defects. Internal quality factors such as maturity, sugar content, acidity, oil content and internal defects, however, are difficult to evaluate non-destructively. Methods are needed to better predict the internal quality of fruits and vegetables without their destruction. Recently, there has been an increasing interest in non-destructive methods of quality evaluation, and a considerable amount of effort is being made in this direction. But the real problem is how these methods are to be exploited practically on commercial scales and what are the constraints faced in implementing them.

1. Introduction

Food is processed for its preservation, hygienization or value addition. To date, the food preservation technologies such as canning, dehydration, freezing, pasteurization and controlled atmosphere and modified atmosphere packaging have been the main processes employed to preserve foods, with the use of antimicrobials and microwaves also being employed more recently. In future, however, technologies such as exposure to ionizing radiation, high pressure processing, ohmic heating and pulsed electric field processing, could potentially be the new alternatives to the above food preservation technologies.

Irradiation of food involves the exposing of food, either in prepacked form or as such to controlled doses of ionizing radiation being generated either by electrically driven machines such as electron beam accelerators, x-rays or gamma rays produced by radioactive isotopes such as CS-137,CO-60, to achieve certain desirable objectives. The process of exposing a range of food stuffs to specific doses of ionizing radiation is being used to extend the shelf life of food stuffs, to improve their overall safety and quality by eliminating pathogenic bacteria, by reducing number of food spoilage organisms, to reduce the bacterial load on herbs and spices and thereby making them safe to incorporate into food stuffs, to inhibit sprouting in stored tuber and bulb crops such as potatoes, onions and garlic, to disinfest grains, grain products and tropical fruits to prevent damage to the commodity and to meet the quarantine regulations(Arun Sharma, 2004, Farkas, 2006).

1. Introduction

Pectin is a polysaccharide present in the middle lamella of plant cell walls. The firmness and structure of the plant tissue are attributed to the presence of pectin in the middle lamella. The insoluble form of pectin is called protopectin and the soluble form is called soluble pectin (Kertez, 1951). Protopectin is abundant in green fruits and contributes to hardness of cell, where as soluble pectin is responsible for viscous nature of juice and pulp. Conversion of protopectin to soluble pectin results in loosening of the bonds between the cells and softening of the fruit tissues. Protopectin is reported to be hydrolyzed to pectin by enzyme action during ripening. Protopectin on restricted hydrolysis yields pectin or pectinic acid. Braconnot (1825) discovered pectin as the gelatinous principle of fruits.

1. Introduction

At present there is an increasing demand for colourants from natural sources. Since there is a possibility of banning of synthetic colours in view of their carcinogenic properties and already a reduction in number of permitted synthetic colours from 13 to 8 numbers in our legislation (PFA, 2005), the demand for natural colours is evident. In Japan and European countries because of the green movement, the demand for synthetic colours has been reduced. Synthetic colours in global market account for 400 million dollars. Despite processing limitations and higher costs, the global market for natural colours is estimated to be more than 939 million dollars (Espszezola, 1998). Color is recognized as a major factor affecting food acceptance. The consumer expects a specific food to possess a well defined colour and rejects any appreciable deviation from the normal. The change in colour during the preparation of food is a useful guide to quality control and is used by many food processors as the criterion for selecting raw materials. The characteristic colour of raw food is due to the natural pigments present in the plant and animal material. These can be enhanced in processed food products through the addition of food colourants. Addition of colour can make up for the colour losses during processing. Some of the major groups of colours are anthocyanins, carotenoids, betalains, chlorophylls, flavones and chalcones. Some of the plant sources of pigments are kokum, roscelle, chilli, marigold, beetroot, grapes and safflower. Sources of natural colours can be plants, animals or microbes. Fruits and vegetables form one of the main plant sources of pigments. Some of the plant materials rich in colours viz., alfalfa, marigold, safflower, strawberry, aronia fruits, grapes, red cherries have been exploited for pigment extraction and the results have shown positive effects. Some of the interesting features of the work carried out by researchers in this area are presented in the following sections.

1. Introduction

In this era of genomics, proteomics and metabolomics the challenge in nutritional science is to clarify human nutrient requirements and design nutritional strategies to promote health and functional longevity. Our ancient Indian belief that ‘we are what we ate’ and our future health as individuals may well depend upon what we eat today. Plant-based dietary antioxidants are believed to have an important role in the maintenance of human health because our endogenous antioxidants provide insufficient protection against the constant and unavoidable challenge of reactive oxygen species (ROS). We have various endogenous defense chemicals but they are inadequate to prevent oxidative damage that makes human system prone to various degenerative diseases. Hence, it is necessary for increased intake of dietary nutraceuticals that may help maintain the balance between oxidants and antioxidants, slow age-related changes, and prevent onset of degenerative diseases.

1. Introduction

Pulpy and juicy fruits like orange, guava, banana, grape, mango, papaya, pears, apples and jackfruit can be converted into fruit products like squashes, juices, cordials and ready-to-serve (RTS) fruit beverages. These RTS fruit beverages are both refreshing and thirst quenching and have become very popular. Liquid fruits are the clarified juices prepared from these pulpy and juicy fruits. There is a demand for liquid fruits in the international market for various applications. The liquid fruits can be used as a natural alternative to synthetic beverages. They can be suitably concentrated or diluted, blended with other juices and also can be carbonated as fruit based soft drinks. Removals of pulpy material from the juices make them easier to preserve by pasteurization and are amenable to carbonation. Pulpy fruits can be successfully processed into liquid fruits (clarified juices) by using pectic enzymes. The emphasis of the fruit juice processing industry has, so far, been mainly on conventional clarification processes like enzymatic and chemical treatments followed by filtration using filter aids; and concentration by vacuum evaporation.

1. Introduction

Intermediate moisture foods are semi moist foods that have some of their water bound by glycerol, sorbitol, salt or certain organic acids, thus preventing the growth of many microorganisms (Stewart et al. 2001). It is now well recognized that fruits and vegetables are dehydrated to an intermediate moisture level (20-50%) (Stewart et al. 2001; Purvi et al. 2003). As the intermediate moisture products are characterized by a semi moist consistency so these foods have enough moisture content to permit easy chewing but low enough water content to prevent spoilage production of intermediate moisture foods is based on an increased scientific understanding of the chemical reactions involved in traditional food preservation methods (Purvi et al. 2003).
There will be better retention of original flavor and texture compared to fully dried products, with concomitant reduction in bulk, weight and cost of packaging, transportation and storage. Such intermediate moisture foods are more appropriate for developing countries in view of their minimal processing requirements, stability under ambient conditions, safety, convenience, ease of nutrient content adjustment, energy savings and low capital investment. They are also eminently more suited than dehydrated or canned foods for military rations (FAO, 2005).

1. Introduction

There is intense commercial interest in dehydrated fruit and vegetable products especially mango powder, banana powder, orange powder, papaya cereal flakes to powder, tomato juice powder and other vegetable powders, which are in great demand for soups, biscuit type cookies supplemented with fruit powders (Ana Maria et al. 2009; Sunita and Chauhan 2008), pizza mixes and sauces. Natural fruit and vegetable powders are gaining lot of popularity in recent years as they are very easy to handle after production, require minimum storage space and they are attractive. Tamarind powder is developed from tamarind fruit (Tamarindus indica) (Manjunath et al. 1991) and recently cashew apple and guava residues from fruit juice industry were successfully converted into fruit powders and used at different levels of wheat flour substitution for cookies formulation (Ana Maria et al.2009) and fruit puree like papaya can be mixed with cereal flour to prepare slurry and after gelatinization, the slurry can be useful for preparing drum dried flakes and powder (Sunita and Chauhan 2008). Tropical fruits are exotic in flavor but their juices and purees are seldom available in dehydrated powder (James, 1971). Citrus juice concentrates were produced during world war II in powdered form by using spray, drum, vacuum-puff, and freeze drying (USDA, 1962). The preservation of fruits and vegetables by dehydration offers a unique method, which may be considered as an alternative low cost preservation technique. A shift from fresh to more and more processed foods with significant value addition is bound to occur sooner or later considering the socio-economic changes taking place in the country and the rapid integration of Indian economy with global system. Most popular brands are found in the “ready to consume” food sector.

1. Introduction

Bamboo has historically been an integral part of human culture. Bamboo is a mystical plant representing symbol of strength, flexibility, tenacity, endurance and compromise. Throughout Asia, bamboo has for centuries been integral to religions, ceremonies, art, music and daily life. Bamboo provides numerous environmental benefits such as playing a critical role in the balance of oxygen/carbon dioxide in the atmosphere. Bamboo is the fastest growing canopy for the regreening of degraded areas and generates more oxygen than equivalent ultraviolet rays. It is an atmospheric and soil purifier. Its soil conservation properties create an effective watershed, stitching the soil together along fragile river banks, deforested areas, and in places prone to earthquakes and land slides. Its fast growing and high yield nature makes it a highly valued renewable resource. Its low cost and abundance call for its utilization to a full extent. 

1. Introduction

 Mushrooms have been part of man’s diet for centuries (Rajarathnam and Shashirekha, 2003). Mushrooms grow on wide range of agro-residues, biodegrade and biotransform them into edible fruiting bodies (Rajarathnam and Zakia Bano, 1988a; 1988b; 1990; Zakia Bano and Rajarathnam, 1988; Zakia Bano et al., 1993; Rajarathnam et al., 1998). Their post-harvest life is very ephemeral at room temperature (Rajarathnam et al., 1983) due to delicate flavor (Rajarathnam et al., 1990) and high moisture content, with a range of chemical constituents (Zakia Bano and Rajarathnam, 1986; 1982; 1988; Rajarathnam and Zakia Bano, 1990; Rajarathnam et al., 1983; 1992). Since, they contain large quantities of water and therefore suffer considerable weight loss during transportation and storage, causes serious economic losses, due to reductions in weight and quality (Gray, 1970). When the supply of water, organic substances and minerals are cut off at harvest, the fresh mushroom enters a deterioration or perishable phase. Cap opening and stem elongation are the usual symptoms of senescence constituting visible evidence of deterioration. At room temperature, the shelf-life of mushrooms cannot be for more than 24 h (Rajarathnam et al., 1983). During this period, there are considerable changes in color, texture and taste. In addition, water is continuously being lost as a result of transpiration and respiration. Additional loss occurs from surface cracks and bruises that develop during growth and handling (Salunkhe et al, 1991). Fresh mushrooms are white or light buff, with no dark marks on either the cap or stem. The veil is closed and the gills are not visible. The upper surface of the caps should be strongly convex and stems should be plump rather than elongated. Mushrooms are grown on compost, usually in mushroom houses where the temperature and humidity can be controlled. Eventually after harvest, the mushrooms can never be able to withstand any increase in temperature and decrease in relative humidity. Mushrooms are commercially preferred at the immature stage characterized by closed caps, invisible lamellae, round stipe and light color. Agaricus development is classified into various stages (Table 1). Thus, the concept of physiology of fresh mushrooms being very complicated, bears a great impact on the delicate problem of extending the storage life. The various means and methods studied and adopted by various researchers to aim at extended storage life of fresh produce, underlined by its physical, chemical and biochemical properties and also development of value added products are critically evaluated.

1. Introduction

Fruits and vegetables in fresh form in general contain very high water content, with the fast rate of metabolic activity, including respiration rate, which may vary with the fruit type. Accordingly, the storage life at room temperature is considerably less, to expect acceptable quality. A range of transformational changes occur in various features of the fruits and vegetables, such as color, flavor, texture, structure, sweetness, sourness, pungency, astringency and so on. Phenolic browning of mushrooms, intensive softening of papaya, coloration and softening of ripe banana, softening of pear and jackfruit , flavor transformations of mango, banana and jackfruit after ripening, their color and texture transformations, are classic examples of post-harvest changes in fresh commodities, over a course of storage period at room temperature. These physical and sensorial perceptions of fresh commodities over a length of storage period are based on the range and multitude of operations of physical, chemical and bio-chemical reactions occurring in various constituents of the fresh fruit or vegetable such as moisture, pigments, vitamins, pectin, cellulose, hemicelluloses, phenolics, lignin, sugars, flavor compounds, amino acids, fatty acids and so on. In order to increase the storage stability, the fresh fruits and vegetables are processed and converted into various products such as juice, RTS beverages, jam, jelly, marmalade, fruit spread, dehydrated, spray dried powder, frozen stored, fruit cereal flakes, canned, candied, fruit bar and so on. Based on the nature of processing, the original form, shape, size, texture and structure are transformed, however with due maintenance in storage acceptability. A number of external factors are applied to achieve this product range such as heat, air velocity, pressure, radiation, chilling, freezing, vacuum impregnation etc. The ultimate quality of the final product is essentially an interaction between and amongst the various chemical constituents so characteristic of each fruit or vegetable under study, and a sum total of positive and negative reactions related to sensorial acceptability of the product. This quality is again a function of the storage period and the conditions of storage. Consumers in modern days are more health conscious to choose between consumption of fresh or processed fruits and vegetables. For trade over distance and time and particularly for geographic regions not producing a particular fruit or vegetable, it is of utmost importance to process the fresh produce. Enzymatic transformations in color, texture and flavor deserve utmost attention to ensure acceptable quality of the processed product, in particular over the course of storage period or until consumed after transportation and marketing. Microbiological quality of the product in final form is a most vital factor of consumers' health and this is dependent on water activity, sugars and protein / amino acid contents. In this regard, additives and preservatives come into picture. Strict regulations are imposed on their use, type and concentration over a storage period, for healthy consumption. Accordingly, this chapter would deal with several examples of processing conditions influencing the quality of the product, that emanates. Processing involving chemical, bio-chemical, engineering, bio-technological and microbiological methods to achieve a product are vivid, varied and different to different species / variety of fruits or vegetables to target different products.

1. Introduction

Processed foods have become a way of life in the modern world. Manipulation of chemical and physical properties facilitated by modern food technology and followed by addition of food additives has created a plethora of innovative food products that offer consumers greater convenience, variety, safety, satiety and quality.
Food additives have been in use for centuries for preservation, for providing improved appearance or desired texture and flavour. Preservation of foods started with salting and smoking. The Egyptians used colours and flavours, Romans used saltpeter and in India, turmeric is being used. Similarly additives such as baking powder as a raising agent, thickeners for sauces and gravies and colours- synthetic as well as from natural sources are being used.
Today more than 2500 food additives have been in use mainly due to the spurt in the research activities in food science and technology that are aimed at providing different characteristic functions to foods. Out of these, about 1300 are the flavouring additives.

From the earliest time, man had to conserve and preserve his food, so that surplus at harvest following a successful crop can be stored for use throughout the year. Prime agricultural products in general and more so with fruits and vegetables which are being processed world wide or preserved to a more stable form so that they can withstand transport, handling and storage over a long period. As civilization developed, man learnt to preserve fruit and vegetable products with salt, spices and by drying , smoking or cooling which could extend their shelf life. Later by experience, he learnt that by protecting it from environmental factors such as air, moisture and light, the shelf life of these processed products could be further increased. He tried to keep them dry and covered to protect from insects and rodents. As with solid foods, primitive man experimented with beverages also. It is likely that the first beverage known to him after water was fruit juice. This undoubtedly led to the discovery of wines made from the fermented fruit juices. Later on, preservation methods and development of packaging materials underwent drastic changes.

1. Introduction

Fruits and vegetables have been an integral part of man’s diet from immemorial times. Fruits are the portions of plants that bear seeds, while vegetables are the edible components of a plant, including the leaves, stalks, roots, tubers, bulbs, flowers and seeds. These can be eaten raw or cooked. Fruits and vegetables can be preserved for short-term intervals under refrigeration, with or without receiving a minimal treatment like slicing, chopping, shredding or peeling. Fresh produce may also be irradiated or packaged in controlled or modified atmosphere in films for short-term storage. Long-term preservation includes canning, juicing, drying and addition of preservatives. Food contamination with hazardous biological agents remains a worldwide challenge in food safety and nutrition (Kenny 2002; Schlundt 2002; Tauxe et al 1997). Microorganisms form part of the epiphytic flora of fruits and vegetables and many will be present at the time of consumption. Production practices, growth conditions and the location of the edible part during growth (soil, soil surface, aerial part) will in combination with intrinsic, extrinsic, harvesting and processing factors affect their microbial status at the time of consumption. Man-made sources may be directly from farm laborers and from the equipment used for harvesting or storage. The types of microorganisms on fruits and vegetables would also vary with the orchards, vineyards or growing fields. The resident microflora normally subsists on the slight traces of carbohydrates, proteins and inorganic salts that dissolve in the water exuding from or condensing on the epidermis of the host. The numbers of bacteria present will vary depending on seasonal and climatic variation and may range from 104 to 108 per gram. The inner tissues of fruits and vegetables are usually regarded as sterile (Lund 1992). However bacteria can be present in low numbers in the insides of the fruits and vegetables as a result of the uptake of water through certain irrigation or washing procedures.

1. Introduction

The chemical composition of a food is of utmost importance from many standpoints, including nutrition, safety, and stability to microbiological, chemical or physical changes. Analysis of these food components is required to provide nutrition labelling for informing the health-conscious consumer, for quality assurance during processing and storage, and for regulatory purposes. The methodology used in analysis will depend on the particular component and the nature of product being analyzed, the purpose of the analysis, and the availability of resources. The emphasis of this chapter is on understanding the principles, procedures and calculations involved in estimating a particular component in fruits, vegetables and their products.

1. Introduction

Mushrooms represent a highly specialized group of fungi, mostly basidiomycetes, with production of fruiting bodies bearing the spores for continued propogation. The fruiting bodies vary greatly in shape, size, color, texture, structure and aroma (Rajarathnam et al., 1998). They are endowed with the unique ability to biodegrade cellulosic wastes, including lignin, and biotransform into edible fruiting bodies (Rajarathnam et al., 1992, 1998, Rajarathnam and Zakia Bano, 1990). Their chemistry is also varied comprising characteristic polysaccharides, phenolics, proteins, amino acids, peptides, lectins, fatty acids, minerals, and so on (Rajarathnam et al., 1998). The wide spectrum of compounds have endowed the mushroom species with a spectrum of biofunctional activities of medicinal importance and accordingly their role in human health are implicated through studies on chemical, cell culture and animal feeding experiments. Vast literature available on this subject is condensed for presentation here.
Fifty nine medicinal species are reported from Diaoluoshan Nature Reserve in Hainan Province, China (Li et al., 2003). A health food made from luminescent mushrooms (Mycena chlorophos) is described. The luminescent parts that emit light in the carpophore of the mushrooms are dried without thermal decomposition and pulverized (Sugimoto, 2006). Consideration is given to the health promoting properties of 3 types of Asian fungi, namely, shiitake (Lentinus edodes), reishi (Ganoderma lucidum) and maitake (Grifola frondosa). Properties considered include beneficial components (e.g polysaccharides, vitamins, amino acids) and effects on the immune system (Anon, 1997). Auricularia auricula (kikurage or tree-ear) and Tremella fuciformis (shirokikurage or white jelly-leaf) are widely used in Chinese cuisine. Chemical structures of some of the polysaccharides from A. auricula and T. fuciformis, in relation to their medicinal and nutritional effects are described (Misaki and Kakuta, 1995).

1. Introduction

 Banana is the developing world’s fourth most important food crop (after rice, wheat and maize) accounting for 70 million metric tons per annum (FAO stat, 2007 faostat.fao.org/site/567/Desktop Default.aspx?). Banana is also the second highest fruit crop in the world, representing a wide range of varieties of cooking and dessert types, providing a staple, nutritious inexpensive food for millions of people. The word “banana” is a general term embracing a number of species or hybrids in the genus Musa of the family Musaceae known simply as the banana family. Two Musa species namely Musa acuminata and Musa balbisiana, out of the 28 described were first noted in 1865 by Kurz as being the origin of most of the commercial clones (Stover and Simmonds 1987). Cultivated clones are parthenocarpic, mostly sterile with starchy fruits. Indeed, wild types are very fertile; their fruits are full of seeds with little starch, and are seldom fit for human consumption. Its abundance, varietal diversity, availability round-the-year and low cost make banana an important commodity for the religious occasions in many tropical countries. The vegetable bananas, generally grouped under ‘Plantains’ are larger, more angular than dessert type and are generally intended for cooking unripe, although ripened ones are quite like dissert bananas.

1. Introduction

As dealt in earlier chapters, fruits and vegetables represent the most essential of horticultural component for acreage of production, yield, nutritional and nutraceutical values, of definite taste, texture, flavor and colour, involving defined health and medicinal benefits. Every year and over the course of every ten years, significant quantum of research data accumulates on the various facets of fruit and vegetable technologies, and also trends in production, processing and marketing, may also tend to change. At every stage, more thinking has gone to improve the technology, product quality and cost economics to suit wider markets, both domestic and foreign. It is a continuous endeavor to record newer and newer problems emerging and to set the strategies to solve them. Several relevant references, fitting to the various aspects representing the cross section of the fruit and vegetable technologies are dealt here, to conclude the subject and spell out the future.
Consumer demand for healthy convenience meals with ‘near fresh’ properties challenges researchers and industry to develop new or improved conservation procedures for processed products. Development of a dehydration process based on electromagnetic energy (EME) may bring about a major breakthrough with respect to retention of product quality and improved rehydration characteristics (Nijhuis et. al., 1996). Economic potential and current limitations of fruit and vegetable processing in India included improvements in preliminary treatment (harvesting, washing/cooling) precooling (including refrigerated transport/storage) and processing of juices and pulps. Establishment of a National Horticulture Board has aided to provide market information and so aid growers to get remunerative prices (Anon, 1993). The use of food irradiation as a quarantine method for treatment of food and agriculture commodities was organized by the joint Food and Agriculture Organization/International Atomic Energy Agency Division of Nuclear Techniques in Food and Agriculture, held in Kuala Lumpur, Malaysia, on 27-31 Aug., 1990. (FAO,1992). This has been experimented with various commodities, particularly for export trade of fruits like mango, as stipulated by the importing country like U.S.A.

Genetic architecture of a population is the result of prolonged natural selection. The populations which exist in diverse environments might have been strongly diversified genetically. So, it is necessary to understand the extent and rates of genetic divergence existing between the diversified forms or types. Genetic diversity must be sufficient enough to justify breeding effort. Genetic diversity may be available in improved germplasm or it may exist only in genetically inferior stocks. The availability of statistical tools to quantitatively measure the genetic divergence between two or more populations and the relative contribution of individual characters to the total divergence have permitted to trace the evolutionary patterns in some crops such as rice and tobacco and in choosing the parents for hybridization in crop plants (Rao, 1958; Blackith, 1960; Morishima and Oka, 1960; Murthy et al.,1962). Among the several statistical methods developed for measuring the divergence between population, multivariate analysis (D² statistic) developed by Mahalanobis in 1936, has been found to be potent tool.

Mahalanobis D² analysis is an effective tool in quantifying the degree of divergence at genetic level and provides a quantitative measures of the association between geographic and genetic diversity based on generalized distance.

Rice (2n = 24) is an annual grass (family: Graminae) with terminal panicles bearing the grains. It originated in Asia between the fourth and fifth millennia B.C. A substantial portion of the people in south and Southeast Asia and the southern part of China are depending on rice as staple food (Chang, 1976). Rice is planted in the most diverse environmental conditions of any major food crop, from sea level to around 3000 m altitude and from 30°S to 49°N. Temperature and day lengths are therefore quite diverse in the rice growing areas. Rice is also grown under water regimes ranging from dry land to deepwater fields where water may reach 5 m depth. The wide geographical distribution of rice and its early history of cultivation have resulted in the development of a great diversity of varietal types (Vergara, 1985).

Rice has been used as food by man for over 10,000 years and has fed a great number of people for a longer period than has any other crop. “Rice is life” for almost four billion people of the world contributing over 20 per cent of the total caloric intake of human population (Chaudhary and Tran, 2001). Rice is cultivated in 113 countries and on all continents except Antarctica and it is the staple food for 17 countries in Asia and the pacific, eight countries in Africa, seven countries, in Latin America and the Caribbean and one in the near east (IRC, 2003).

Globally rice is grown in around 155 million ha occupying one tenth of arable land, with an annual production of 579 million tonnes of rough rice (Iiyas Ahmed, 2003). The average productivity of 3.89 t ha^-1 of rice provides a per capita. Consumption of 100 to 240 kg per year across the globe. Over 90 per cent of the world’s rice is produced and consumed in Asia and more than half of it from India and China exploiting maximum arable land. More than two billion people obtain their 80 per cent calorie from rice and its derived products from 90 per cent of world’s rice area (FAO, 1999). Rice based on production systems and their associated post harvest operations employ nearly a billion people in rural areas in developing countries (IRC, 2003).

In recent years, we are just experiencing marginal surplus production in cereals leading to self-sufficiency through green revolution. However, the shortage of production in edible oils has drawn the attention for the increased cultivation of oil seeds, and increased productivity per unit area to provide sustainable food and nutrition security (Swaminathan, 1989).

The importance of oil seeds cannot be over emphasized in the Indian economy. Oilseed occupied nearly 19 million hectares, next only to food grains, in 1986-1987. Yet, the domestic production in the country has lagged far behind the increasing demand for edible oils, necessitating a massive import of edible oils which lead to the drain of the valuable foreign exchange. The total import bill on edible oil has increased from 1.41 per cent in 1970-71 to 3.05 per cent in 1986-87. Even then, the annual per capita availability of edible oils registered only a nominal increased from 3.5 kg to 5.9 kg during the same period, against the nutritional norm of 14 kg (Suresh Pal, 1989). Due to the concerted efforts made through the ‘Technology Mission on Oilseeds’, oil seeds production reached a peak of 178.9 lakh tonnes during 1988-’89 in India (GOI, 1990a). This is an impressive achievement in Indian Agriculture, to reduce the bill on the import of edible oils from 4.11 per cent (1987-’88) to 2.58 per cent (1988-’89) (Gill, 1990). Further efforts in increasing oilseeds production definitely will go a long way in drastically reducing the present import bill.

Among the oilseed crop, sesame (Sesamum indicum L.), “The Queen of Oil Seeds”, is one of the important ancient and traditional crops occupying third position in terms of acreage on the oilseeds map of the country. It is commonly known as Gingelly, Til, Benniseed and Simsim. It is an important source of edible oil for the nutritional refugees of most part of the world, especially for India. The oil is rich in oleic and linoleic acid. In addition, it serves as a good source of proteins, vitamins and minerals (Nagaraj, 1990). Its high keeping quality deserves special mention.

Introduction

India is the largest producer of pulses in the world, both in quantity and variety. But, presently, India is one of the largest importer of pulses. India imported pulse grains upto a tune of approximately 4000 crore rupees during 2006-07. It accounts for about 20 per cent of the total import bill during 2006-07. This is because of the green revolution (quantum jump in cereal production) accompanied with changes in the infrastructures and incentives including input supplies and price support systems in favour of major cereals. It altered the traditional cropping pattern against pulses with decades of emphasis on research as well as production in superior cereals coupled with a near total neglect of the rainfed areas, pulses were driven out of not only the irrigated areas, but also the rainfed farming and were relegated to the marginal lands. Further more, the weak infrastructural support for input supply, credit and marketing in the rainfed areas, the traditional home of pulses, also adversely affected the prospects for pulses. A vicious circle of low input use and low output thus got built in. Lack of processing and marketing facilities in pulses also contributed its share to the woes of pulse growers. The increasing shortage of pulses, resulted in the need for more and more import which, in turn has dampened the speed of rejuvenation of pulses sub-sector of agriculture sector.

The net per capita availability of pulses has fallen from 60.7 (1950-51) to 33.4 g (1991-92). On the contrary, the daily per capita availability of cereals has registered an increase from 334.2 (1950-51) to 443 g (1991-92). It leads to increase in the pulses/cereal ratio from 0.18 to 0.08 g i.e., by 55 per cent. This is despite the increases of 24.36 per cent in area; 61.71 per cent in production and 29.93 per cent in production. It is significant to note that almost all these increases had taken place during 1950-51 to 1960-61. The area, production and yield of pulses have either stagnated or declined since then. This stagnation of pulse production and productivity should be viewed seriously not only from the point of security and quality of food for our people, especially the poor and the rural population, but also from the soaring import bill, imbalance and distribution in the cropping pattern and resource allocation among various sub-sectors of agriculture.

Introduction

The nature and magnitude of genetic variability present in the genetic stock afford the plant breeder, information to formulate a purposeful breeding programme for crop improvement. The association and the influence of yield components with yield, their heritability and genetic advance would characterise the various steps in the breeding programme in achieving the aim of the breeder. Studies on these lines in various crops have hastened the realization of crop improvement in general.

India grows a variety of pulse crop which probably no other country in the world grows. These are multiple utility, energy high crops as they provide protein for human consumption, green nutritious fodder and enrich soil fertility through biological nitrogen fixation. Vigna radiata (L.) Wilczek, commonly known as greengram or mungbean, is the most widely distributed of the six cultivated Asiatic Vigna species.

The current breeding approaches to yield improvement in greengram are based on the recognition that this crop have lost a large part of their genetic variability in the process of adaptation to stress environment. This variability must now be regenerated.

The foremost need for this purpose is the collection of germplasm from different parts of the world and the organisation of a very intensive hybridization programme, using diverse genetic stocks as parental lines. Selection of parents for hybridization based merely on geographic diversity can no more be a suitable criterion. The importance of genetic diversity has long been appreciated by crop specialists. Such an analysis will eventually help to choose desirable parents for hybridization and evolve superior genotypes.

In recent years, we are just experiencing a surplus production in cereals and oil seeds leading to self-sufficiency through green revolution and yellow revolution. However, shortage in the production of vegetables has drawn the attention for increasing the cultivation of vegetables to provide food and nutrition security.

Vegetables are being cultivated over an area of 49 million hectares with the production potential of 487 million tonnes in the world. This accounts for 2.85 per cent of total cropped area in the world. India is the second largest producer of vegetables next to China, sharing nearly 12 per cent of the total world output (Joshi and Shukla, 1997). Vegetables occupy nearly 8.02 million hectares with the production potential of 133.10 million tonnes in the year 2009 in India (Anonymous, 2009).

Bhendi (Abelmoschus esculentus (L.) Moench) is an important member of family malvaceae and commonly known as okra or ladyfinger in India. It is one of the most ancient and traditional vegetable crops grown in tropical and subtropical regions of the world (Martin and Ruberte, 1978). Bhendi is originated from tropical Africa with 2n = 8x = 72 or 130 or 144 chromosomes and is an allopolyploidy in nature (Joshi and Hardas, 1956; Suresh Babu, 1987). Martin (1982) reported that it behaves as a diploid. Under the genus Abelmoschus, there are 30 species in the old world and four in the new world (Joshi et al., 1974). Out of them, Abelmoschus esculentus, is the only species known to be cultivated. Bhendi is being raised in India in an area of 0.44 million hectares with an average production of 4.52 mt with the productivity of 10.27 t/ha (Anonymous, 2009).

The Coconut palm is a monotypic species of the family Arecaceae, under the tribe Cocoideae. It is considered as an important commercial crop in more than 18 countries in the world. The palm provides food, drink, shelter and also supplies raw materials for a large number of industries. Every part of the palm is utilized for some economic purpose or another. Hence, it is referred to as ‘Tree of Wealth” or the “Tree of Life” (Satyabalan, 1993). It is native of South East Asia. Genetic diversity has become one of the keywords of scientists who are concerned about the sustainable management of different tree crops. Genetic diversity plays an important role in tree breeding, because hybrids between populations of diverse origin, generally display a greater heterosis than between closely related parents (Zobel and Talbert, 1986). The present study was formulated to identify divergent parents for future breeding programme.

Two hundred and fifty genotypes of coconut cultivar Chawghat green dwarf, distributed in the two districts of Kerala viz., Kottayam and Pathanamthitta were evaluated for nut yield per plant during June-July, 2000. Seventy five genotypes, which had single tree nut yield of more than population mean ± 2 SE were selected as per the method outlined by Ledig (1974). These 75 genotypes were observed for 10 nut and endosperm characters in two seasons (years), during June-July 2000 and 2001.

Each tree was considered as a single genotype. Thirty nuts from a single tree were collected and divided into three replications (Chauhan and Kanwar, 2001; Thirugnanakumar, 2006a, b). Observations were recorded on 10 nut and endosperm characters viz.,1) oil content (%), cold percolation method; (Kartha and Sethi, 1957), 2) weight of unhusked nut (g), 3) weight of husked nut (g), 4) diameter (polar) of the husked nut (cm), 5) diameter (equatorial) of the husked nut (cm), 6) thickness of husk (cm), 7) husk: nut ratio, 8) thickness of meat (mm), 9) weight of kernel (g) and 10) weight of copra (g). The mean values so obtained were subjected to statistical analyses, in Randomized Block Design, as suggested by Chauhan and Kanwar (2001) and Thirugnanakumar et al.(2006a, b). The D² estimates were made following Mahalanobis (1936), as described by Rao (1952). Clusters were prepared following Tocher (Rao, 1952).