eChapters

Principles of Incubation

Incubation is a process by which the embryo within egg develops into a fully formed chick capable of breaking free from the shell. Basically, when a hen incubates an egg, it means she is on the egg in order to keep it warm for a certain period of time, 21 days for chicken, until the chick embryo has fully formed and is ready to hatch. The incubation period in other species is given in Table 41. The following factors affect the incubation on egg

1. Temperature

Incubator temperature should be maintained between 99 and 100 oF. The acceptable range is 97 to 102 ^oF. Overheating is more critical than under heating. An incubator should be operated in a location free from drafts and direct sunlight. Temperature is probably the most important single factor influencing the development of the embryo. A higher temperature will advance the hatch and a lower temperature will delay hatch. Younger embryos are especially susceptible to high temperatures because the upper lethal limit is very close to the optimum incubating temperature. High temperature will cause the embryonic membranes to dry out too soon. Chicks that hatch may have an unsteady gait.

Artificial insemination (AI) is the deposition of the semen or male germ cells (spermatozoa) in the female genital tract by artificial means (instruments). Artificial insemination includes collection of semen from the male, preservation, handling and deposition into the female reproductive tract hygienically replacing natural mating by a male. In India this technique is gaining momentum in chickens due to improved animal husbandry practices and economic considerations, initiated by IVRI, Izatnagar and JNKVV, Jabalpur. In many parts of the world, turkey, ducks, goose and guinea fowl are bred solely by AI. Chicken species are endowed with the behaviour and capacity of each male to mate several females and also 25 to 40 times a day. Further, the process of ovulation in birds is almost daily and stimulated by intensity and duration of light.

In modern poultry managemental practices of using cages, environmentally controlled houses and breeding and hybridization techniques employed for developing highly economical chickens, selection for faster growth and heavy body weight in broilers, which has led to loss of fertility and hatchability and use of dwarf female parents in broiler industry have demanded the use of AI in poultry.

Breeder management includes pure line management, parent stock management, and grandparent stock management depending on the context. Except for small variations in management among these stocks basics are common within layer breeder stocks and broiler breeder stocks. The main objective of the breeder management is to produce more fertile eggs per pullet and increasing the hatchability by hygienic handling of these fertile eggs.

Location of the breeder farm

Location of the breeder farm should be away from commercial poultry farms in order to prevent the spread of diseases between the flocks. However, they must be in close vicinity of the city/town to have a good transport facility and other amenities such as water, electricity and availability of labour.

Chicken’s eggs have been used as a food item by human beings since antiquity. The egg is composed largely of the proteins out of the three most important dietary essentials (proteins, fats and carbohydrates). The egg proteins are highly digestible and remarkably complete, containing the most important essential amino acids. The amino acid profile of egg is similar to the ideal balance of amino acids needed by humans. It also supplies various minerals, some in significant amounts, and contains a range of vitamins. The nutritive excellence of the egg enhances the value of any food in which it is incorporated. Meeting consumer demands is a constant challenge for the poultry industry. Present day consumers desire somewhat distinct products with respect to safety, healthfulness, freshness, taste, color, etc. To remain competent, various companies have developed several designer and specialty eggs which have appeared in supermarkets.

Common Poultry Diseases

Infectious diseases

Bacteria

Commonly known as “germs”, bacteria are very small living microorganisms. Only a few bacteria cause diseases. In birds these include Salmonella, Clostridia, Pasteurella, Vibrio, Staphylococci, Streptococci, Mycoplasma, Hemophilus, and Mycobacterium etc.

Digestive System and Digestion in Chicken

Studies on structure and functions of digestive system of chicken play important role for their nutrition and feeding. Functions of each part are given below (Fig 35):

Mouth: Birds feed through the beak. The horny upper and lower mandibles form the beak. Lips, teeth, cheek and soft palate are absent. The dagger-like tongue helps to force the feed into the esophagus. Chicken has 24 taste buds with high sense of taste. Absence of teeth makes the particle size of the feed important.

Esophagus (Gullet): It is made of loose fibrous tissue and serves as a tube to pass the food from mouth to crop. This is relatively long because of the long neck of the fowl.

Crop: (Ingluvius): It is a pouch like structure of esophagus to store, moisten and soften the food. It gives information about the feeding habits of the fowl.

Proventriculus (Glandular stomach or True stomach): It is an enlarged glandular ovoid structure of the esophagus connected to gizzard. It secretes pepsin and Hydrochloric acid.

Gizzard (Muscular stomach): Disc shaped muscular organ with two pairs of strong thick muscles and lined internally with a thick horny epithelial covering called the Koilin layer. Coarse materials are ground well by its powerful contractions with the support of the grit that birds consume.

For maximization of productivity in any kind of poultry venture the knowledge on the behaviour of birds and its application play very significant role. Behaviour is the reaction of the whole organism to certain stimuli, or the manner in which it interacts to its environment. Behavioural patterns are not inherited as such, but develop through the process of growth and get differentiated under the influence of genetic and environmental factors. Primary function of behaviour is to enable the bird to adjust itself to some changes in condition, whether external or internal. Most animals have a behavioural pattern which can be tried out in a given situation and in this way they learn to apply one or the other according to that which produces the best adjustment.

Biosecurity means protection against infectious biological agents. These agents include bacteria, viruses, protozoa, fungi, parasites, and any other agents capable of introducing infectious diseases into a poultry flock. Biosecurity therefore means maintaining a flock, poultry house or premises in such a way that infectious agents do not have a chance to enter to cause diseases. The biosecurity may be categorized into three: Conceptual biosecurity, Structural biosecurity and operational Biosecurity.

Importance of Biosecurity

In modern poultry production, birds are reared under intensive system where large numbers are concentrated in small area. As a result, when an infectious agent enters a poultry house, there is probability for widespread dissemination if it is not contained. Besides, the broiler and egg industry of today is under increasing consumer and regulatory pressures to guarantee food safety and meet export requirements. As a result, broiler and layer operations around the world require the supply of breeding stock free of salmonellas specific to avian species (such as S. pullorum and S. gallinarum) and those that could cause outbreaks of human food-borne illness. Inadequate biosecurity can contribute to wide epidemics of highly pathogenic or exotic diseases. An infection by a virulent organism within a facility can be devastating, reducing without overt signs of disease. Once contaminated with pathogens, poultry facilities are extremely difficult and expensive to clean, sanitize and disinfect. Prevention of disease is always less expensive than treatment. The cost of implementing biosecurity system is smaller when compared to financial profit that can be made from production. Good biosecurity is therefore vital requirement in the best possible control of disease.

Water is the most important and abundantly required nutrient for poultry. A continuous supply of clean, fresh and wholesome potable water is essential for poultry. Poultry rearing is becoming more and more intensive with which the chances of the infectious diseases being sustained in the different flocks also increase. Consequently, the need for effective disease control measures to be adopted also gains further importance.

Most often, poultry farmers get alarmed only when the mortality level or death rate in a farm is high. However, even the existence of disease at a sub-clinical level may hinder the performance of the birds, in terms of body weight or egg number; such economic losses, sometimes relatively less and unnoticed, may mean the difference between success or failure in the poultry business. Treatment of a sick flock after the onset of any disease becomes costlier and more frequently impracticable. The recovered birds may not regain their production to original levels and may also continue as source of infection to other healthy birds. Hence, the adage ‘prevention is better than cure’ applies more to poultry industry than any other field.

Vices of poultry are undesirable behavioural pattern manifested by the bird in the flock and spreads fast among the members resulting in financial losses.

Types of Vices

Pecking

Cannibalism

Egg eating

Any deviation from optimum state could be referred as stress. Every living creature has to pass through one or the other type of stresses in life. Most of the farm animals including poultry suffer from various types of stresses. These include due to:

Adverse environment

Managemental practices

Diseases

Nutritional deficiency

Transportation etc.

Management of the poultry house environment forms an essential aspect towards maximizing production performance. Generally, proper maintenance of poultry litter is seldom given emphasis. The condition of litter significantly influences bird’s performance and ultimately affects the economy for rearing. The litter is defined as the bedding materials of around 5-6 cm height consisting of locally available materials like rice husk, peanut hull, wood shavings, paper shreds, sawdust or groundnut hulls. These materials can be used alone or in combination to rear the birds on floor under deep litter system of management. The excreta, feathers, spilled feed and water are mixed with bedding material, get further decomposed due to heat and bacterial action resulting in built-up-litter towards the end of rearing.

In India, poultry judging refers to selection of birds on the basis of their physical appearances, breed characteristics and production performances; however, in other countries, like USA judging is also used for eggs, carcasses and further processed products. The Directorate of Extension, Ministry of Agriculture, Govt. of India annually conducts livestock and poultry shows in various parts of the country in collaboration of state governments. Besides, state Agricultural/ Veterinary Universities or other institutions also conduct such shows. In these shows judging contests are carried out mostly for the undergraduate students by using a score card to grade birds either for production characters or breed characters. The winners are awarded trophies and cash prizes. The birds meant for judging are kept in individual cages and the participants are requested to score under various sub-headings and to finally rank the bird. Any deviation from “ideal” or “perfection” (as described by the American Standard of Perfection or the British Poultry Standards) but not serious enough to constitute a disqualifications in the show room is considered to be a defect. Serious defects are regarded as disqualifications and will bar a bird from winning any prize. Both layers and broilers can be physically evaluated for their performance rating.

Care and Management of Commercial Growers (09-20 weeks) Under Deep Litter System

Grower management essentially remains the same as that of chick management (brooding management) except for the additional space required for floor, feeders and waterers to keep with the size of birds. The growers may be reared in separate grower-houses or continued to be reared in brooder-cum-grower houses.

Floor space: 1260 cm² (1.4 ft²) per bird.

Feeder space: 6-8 cm per bird. One linear feeder of 120 cm length and 8 cm depth for 40 growers.

Waterer space: 2 cm per bird; a circular waterer of 36 cm and 8 cm depth of 6 lit. capacity for 50 growers. Growers are to be provided with fresh, cool and potable drinking water at least twice a day. Water requirement is increased during hot days. Care must be made not to spill water on litter.

Lighting management: No artificial lighting is given other than natural day light since they require only 9 hours of light per day.

Types of Brooders

Brooding is a mechanism of providing auxiliary or supplementary heat to chicks through artificial heat using brooders. Brooders are of several types depending upon the size and the nature of fuel used. These are individual, multiple units or central heating systems run by coal, wood, oil, gas or electricity. The essentialities of a good brooder are i) a dependable mechanism, ii) supply of fresh air, iii) dryness, iv) adequate space, v) easy for cleaning and disinfection, vi) protection against enemies, vii) safety from fire and viii) economy.

i) Hover brooders

Such brooders are more widely used in India wherever electricity is available. They maintain uniform temperature, convenient for operation and require very little attention. However, eclectic brooders do not heat house appreciably in very cold weather. Wet litter may be another problem requiring frequent stirring and renewal of litter.

Housing constitutes the second largest component of cost of poultry production. An ideally located and well planned poultry farm is an essential requirement for efficient egg and meat production. Poultry housing normally serves the following major functions:

Provides shelter and protection to the birds

Provides comfort to the birds.

Helps in organization of large flock into a manageable unit.

Project for Rural People on Chicken

For rural people Desi (indigenous) chicken plays an important role. Family poultry farming is a part and parcel of a typical rural household in India touching social, cultural and economic aspects. People residing in rural areas primarily maintain their indigenous chicken under backyard farming. With the same management system the rural people can rear improved varieties of chicken instead of their traditional counterpart. The improved varieties being Giriraja, Vanaraja, Kuroiler, Gramapriya, Gramalaxmi, Swarnadhara, Krishna J etc. A model project on improved chicken is given herewith:

A unit consisting of 100 number Vanaraja or Giriraja is economical and remunerative to the farmers whose family labour will be utilized for rearing these chickens. Initially, the farmer will buy about 225 straight-run day- old chicks. The males will be sold at 20 weeks of age. The females will be maintained for 1.5 years. In order to have continuous operation, next batch of 225 chicks have to be procured 6 months before disposal of the old batch. Birds will collect their feed through foraging or scavenging in the field. Supplementary feeding will be provided to meet their requirements.

Conservation Biology emerged as the scientific study of the nature and status of Earth’s biodiversity with the aim of protecting species, their habitats, and ecosystems from excessive rates of extinction. Biodiversity itself has a wider meaning unifying and taking into account species, within species breeds/ varieties, ecosystem, genetic and molecular diversity.

Need for Conservation

The progenitor of modern-day chicken has been the Red Jungle Fowl and over the years breeds have been developed slowly for commercial purpose as layers and broilers. However we still have lot of indigenous birds which cannot be defined in either category.

Breeding capabilities Vs biodiversity erosion: Presently only about 3-4 poultry breeding companies provide meat stocks for farms around the world. A similar number of companies supply birds for commercial egg production. As a result modern animal industry now uses only a few breeds of any species. Of the many breeds once commonly seen on farms, many have declined sharply in numbers and others have disappeared almost completely.

Productivity Vs Conservation: On one hand, to increase productivity we want certain natural characters to be eliminated and on the other we talk of conserving the indigenous varieties, which sounds contradictory.

Organic Farming

The FAO/WHO Codex Alimentarius Commission defines organic farming as “a unique production management system which promotes and enhances agro- ecosystem health, including biodiversity, biological cycles and soil biological activity, and this is accomplished by using on-farm agronomic, biological and mechanical methods in exclusion of all synthetic off-farm inputs”. It is a certification of a production system as opposed to the certification of a product. For a product to be certified organic, all operators in the product chain, including farmers, processors, manufacturers, exporters, importers, wholesalers and retailers must be certified organic. The establishment of organic animal/poultry husbandry requires a specific period called as “conversion period”. This period is the time taken between the start of the organic management on farm and certification of livestock farm and its product. Changing from conventional to organic management system for livestock enterprises requires a careful and gradual approach. It is learnt that global organic product has increased 20% annually over the past 10 years. Though Australia, European Union and USA are leading organic producers, a recent study indicated that developing countries including India are also adopting the system and marching ahead.

Selection of site for a poultry farm: The following points should be considered while selecting site or location for a poultry farm.

The farm should be located at an elevated area with proper facilities for drainage.

To protect the farm against strong wind, tall trees may be planted surrounding the farm complex.

The farm should be located not too far from city to bring in and take out materials.

The commercial farm should be located near to marketing centres.

The breeder farm should be located in an isolated area away from commercial farm to ensure biosecurity.

The farm should have an easy access to connecting roads.

The site should have provision of electricity.

The desirable soil type for a poultry farm is loamy or sandy loam.

There should be provision of abundant potable water at the site. The water should be tested for various impurities like total solids, microbiological contamination, high percentage of salts of Na, K and Chlorine, nitrite, nitrate etc. Total bacterial count and Coliform count should be 0/ml.

Poultry meat and eggs have high nutritive value. Egg is used as a standard for measuring the quality of other food proteins. It is a well balanced source of nutrients. Similarly poultry meat is easily digestible, high in protein and low in fat content. It contains all the essential amino acids. Though the poultry meat and egg production have tremendously increased in India during last few decades however due to lack of organized marketing channels poultry producers are not getting reasonable returns. Indian broiler and egg markets are in a disorganized state. In last few decades various efforts have been made so as to organize and co-ordinate marketing channel of poultry meat and eggs. Through these efforts producers are also benefited but only in some particular areas. Therefore, there is need to expand it further covering the country.

What is Marketing?

Marketing may be defined as exchange of a produce for an agreed sum of money. It is a commercial process involved in promoting, selling and distributing a product. In simple words marketing is finding out what customers want and supplying it at a profit. Marketing is a business in terms of customer needs and their satisfaction. As per P. Taylor, marketing is not simply providing products or services; it is essentially about providing changing benefits to the changing needs and demands of the customer.

Among various animal husbandry enterprises, poultry production has emerged as number one position and attained industrial status in many countries, including India.

This tremendous growth in poultry production is due to the following reasons:

There is no religious taboo towards poultry and poultry products.

Egg is the most nutritious, natural, unadulterated and easily digestible food with the highest biological value.

Eggs can be consumed by all age groups and economic classes, since it is the cheapest among all the nutritious natural foods on the earth.

Among various meats, poultry meat has the highest protein, lowest fat and cholesterol content.

Poultry is the best converter of feed into meat and eggs. A hen needs only 1.5 kg feed to produce 1 dozen eggs. Similarly a broiler needs less than 2 kg of feed to produce one kg broiler meat whereas other species need more than 3 kg of feed to produce 1kg of meat.

Poultry has the shortest generation interval among various livestocks.

Brooding and Rearing Practices Used for Chicken

What is Brooding?

Rearing of young ones immediately after hatching for at least 2-3 weeks, either by natural means or by artificial method is called brooding. Brooding is done by two ways i.e., Natural or Artificial ways.

Natural Brooding

In the natural method a desi fowl which acts both as incubator and brooder is used to raise only a small number of chicks. She sits on eggs (chicken) for 21 days to produce chicks from fertile eggs and broods thereafter.

Mixed farming exists in many forms depending on external and internal factors. External factors are weather patterns, market prices, technological developments, etc. Internal factors relate to local soil characteristics, composition of the family and farmers’ ingenuity. Farmers can decide to opt for mixed enterprises when they want to save resources by interchanging them on the farm - because these permit wider crop rotations and thus reduce dependence on chemicals, because they consider mixed systems closer to nature, or because they allow diversification for better risk management. There is wide variation in mixed systems. Even pastoralists practice a form of mixed farming since their livelihood depends on the management of different feed resources and animal species. Mixed farms are systems that consist of different parts, which together should act as a whole. They thus need to be studied in their entirety and not as separate parts in order to understand the system and the factors that drive farmers and influence their decisions. It may be the most important principle to achieve increased production in mixed systems, together with the awareness that crops and animals have multiple functions.

Poultry industry in India has registered a phenomenal growth during the last four decades making it one among the world leaders in poultry production. The development of organized poultry has in fact masked the contribution of backyard poultry or house-hold poultry of rural sector. Backyard poultry production in India is characterized by small flock size consisting of 5-10 predominantly non-descript birds maintained in extensive system under zero input conditions but fetch the owners much needed animal protein and supplementary income. Importance of backyard poultry is well recognized by Government of India and special programmes are formulated for its promotion.

Non-descript Chicken

Maintaining small flocks of local non-descript fowls under free range condition by landless poor, small and marginal farmers are a common sight in rural areas. These birds are very popular due to their adaptability to local agro climatic conditions and management practices with prominent brooding behaviour and mothering ability. But these birds are small in size, poor layers (40-50 eggs/ annum), with small clutch size and intense brooding behavior, thus making them not suitable for commercial exploitation.

Importance of Backyard Poultry Farming in India

Commercial chicken production in India has undergone a remarkable change in the last three decades. While India is among the top five chicken producing and top seven duck producing countries in the world, the gap between the demand and production is still alarming. Average per capita availability of eggs in big cities is 170 while it stands at 9 eggs per annum in the rural areas. Though the commercial poultry sector has made a stupendous progress over the years, the conventional free and backyard poultry farming remain neglected. Backyard poultry farming contributes around 11% to the national production while in certain states like U.P. around 60% of the poultry population is indigenous fowls reared under backyard system. The backyard sector contributed to 23 per cent of the total egg production in 2005-06.

Commercial chicken production is capital intensive and is generally concentrated in and around urban areas. There is a wide disparity in consumption of the poultry products between urban and rural population. Around 75% of country’s population living in the rural areas has limited access to the protein rich poultry products. Protein deficiency is quite common in the diets of rural people. Adoption of rural poultry farming may ameliorate the high incidence of protein hunger in growing children and pregnant women.

It has been seen that the commercial birds have poor immunity against common poultry diseases. As production is inversely proportional to the viability traits, the nutrients absorbed are mostly diverted for growth in commercial chicken. On the other hand, indigenous birds reared in rural areas are resistant to many diseases and pests. Unlike the local breeds maintained in villages, the commercial breeds require high level of input pertaining to feed and health care to maintain production and check mortality.

In modern poultry farming, successful management relies on accurate and complete daily record keeping. Some of the traits may influence the profit of farm, thereby affecting the economics of the farm than the other traits, and hence they are called economic traits. Economic traits can be defined as those traits which are economically important and improvement in these traits would increase the profit of the farm. These traits are generally assumed to be controlled by the genes at larger number of loci. Some of the economic traits in egg and meat type chickens are as follows:

A hen can produce eggs without mating by a cock. Such an egg is edible but infertile and will not hatch. If the hen is naturally or artificially inseminated with poultry semen, the spermatozoon unites with the ovum to form a fertile egg that will hatch after incubation. Unlike mammals, the embryo of birds grows independently within an enclosed hard structure called shell and thus, all nutrients required for embryonic development are contained in the egg. The yolk, albumen, shell membrane and shell protect the developing embryo apart from providing well balanced nutrients.

Male Reproductive System

Male reproductive system (Fig. 15) consists of testes, epididymis, vas deferens and papillae.

Cocks have two ovoid creamy white testes, of which the left one is slightly larger than the right. Testes are located in the fore end of the kidneys in the abdominal cavity. Closely attached to the testes is short epididymis that continues as vas deferens which ends in the cloaca. The copulatory apparatus consists of two papillae and a rudimentary copulatory organ, the phallus which is located on the median ventral portion of one of the transverse folds of cloaca. Accessory reproductive organs like seminal vesicles, prostrate and Cowper’s glands are absent in the cocks. The phallus is small and has associated lymph glands that produce a fluid which is added to the semen.

The spermatozoa pass through the epididymis and are stored in the distal end of the vas deferens. The sperm after mating is stored in the folds in the oviduct of the hen to effect fertility up to six days. The spermatozoa of the cock have a long cylindrical head with a pointed acrosome, a short mid-piece and a long tail. Cocks produce about 0.5 -1 ml of whitish semen per ejaculate with a sperm concentration of 2- 4 billion.

The word indigenous, originates from the Latin work, indigena, implies that the individual and its ancestors originated from a specified country or continent. Presently, certain synonymous words used for indigenous chicken are: ‘native’, ‘local’ or ‘village chicken’. The indigenous fowls are well adapted to the local climate, need less input and produce tasty egg and meat at the least possible cost through scavenging. The birds require no scientific feeding, health care, housing and management and thus make the indigenous birds suitable for backyard poultry farming. Indigenous birds are normally handled by women, can significantly contribute to farmers’ livelihoods through increased food security and cash income. These breeds are self-propagating; contribute to poultry diversity and cultural heritage. Because of their local origin they are less prone to disease or predator attacks, and their cultural and sporting values secure additional income. The prices of egg and meat of local birds are 100- 150 percent higher than that of commercial counterpart. Some of these fowls are described in brief, as below.

The modern breeds of chicken have known to be descended from the wild jungle fowl. India, Nepal, Bangladesh, Myanmar, Thailand, Sri Lanka and Malaysia are the homeland to these jungle fowls. There are four known species of jungle fowl viz. Gallus gallus (Red jungle fowl), Gallus lafayetti (Ceylon jungle fowl), Gallus sonnerati (Grey jungle fowl) and Gallus varius (Java jungle fowl). The domestic breeds of chicken/fowl have originated from Gallus gallus.

The modern commercial poultry production in India is barely 50 years old, although backyard poultry keeping dates back to pre-historic period. In between 1955 to 1965, some Christian Missionaries had imported White Leghorn, Rhode Island Red and White Rock breeds, to upgrade the local chicken, having very high disease resistance power; but highly broody. Later, hybrid broiler (Arbor Acres) and layer (Babcock) strains were brought to India in early seventies, to start modern poultry industry. Among the two, the layer industry took wings early and registered a spectacular growth rate between 1970 and 1985. The broiler industry came to existence five years later and showed 25 -100% annual growth rate initially and 10-20% growth rate subsequently; between 1975 – 2005. The growth indicators of poultry development in India are presented

Introduction

Drought is one of the primary factors responsible for depressing rice yield in chronic areas and in destabilising rice production in drought-prone areas. It is a production constraint common to all rainfed rice cultures: wetland, upland, and deepwater (O’Toole and Chang 1979). Breeding for drought resistance, a major component of the International Rice Research Institute’s (IRRI) Genetic Evaluation and Utilization (GEU) Program since the early 1970s, aims at countering the adverse effects of drought in unfavoured rice production areas.

Rice germplasm has such remarkably rich diversity that a continuous spectrum of genotypes differing in the various physiological mechanisms can be found and is available for genetic manipulation (Chang et al. 1982a). However, effective evaluation methods are essential for unravelling the specific mechanism(s) involved and for devising eficient selection criteria in a breeding program. Moreover, the broad spread in growth duration among rice cultivars makes it impractical to obtain uniform evaluation of a large number of cultivars when they differ in physiological responses that are specific to certain growth stages. Methods that can accommodate large numbers are essential to breeding program.

Introduction

Man’s intervention in the evolution of plants, to adapt them to suit his needs, constitutes the practice of plant breeding. Historically regarded as an art and still too empirical to be accepted universally as a science, it has recently been described as a technology (Riley 1978). Whether art, science or technology, it certainly draws on a wide range of disciplines and embodies all those principles of organisation and management that determine success in any production-oriented programme.

Perhaps the biggest contribution that the plant breeder has made to increased production during the past 50 years has been in helping to alleviate the effects of natural hazards such as lodging, pests and diseases on crop production. While most of this progress has been through the manipulation of biotic stresses, much is still to be achieved under non-biotic stresses such as drought, salinity, temperature, etc. This argument is strengthened by the fact that in spite of the spectacular achievements made possible by the ‘Green Revolution’, the productivity level of most crop plants, including wheat and rice, has remained both low and static under stress conditions. Concerted efforts are needed through an approach of interdisciplinary research, since not much has been done to define criteria for stress assessment and evolving breeding approaches for incorporating stress tolerance in crop plants.

Introduction

Drought is the most common adverse environmental factor which limits crop production in different parts of the world. Often drought is accompanied by relatively high temperatures, which promote evapotranspiration, and hence could accentuate the effects of drought and thereby further reduce crop yields. Since these events occur more frequently in tropical and semitropical regions where most of the developing countries are situated, droughts are often associated with food shortages and an overall setback to developmental activities. Therefore, raising of drought-resistant crops is common sense to achieve stability in production and to enhance the possibility of self-suficiency in food. Consequently, breeding for drought resistance is a major objective of many research programmes in the international and national institutions. This has been so for the past several decades. But, it is disappointing that, there has not been any measurable success in these programmes compared with the success achieved in breeding for yield; or breeding for disease resistance or breeding for quality attributes. In fact, this was amply expressed by Arnon (1980) when he stated “Breeding for drought resistance has been a consistent theme for as long as I remember and probably the greatest source of wasted breeding efforts in the whole field of plant breeding.” However, the fact remains that we do hear of drought resistant varieties in many crops. For example, C-306 in wheat, Lalnakanda in rice and M 35-1 in Sorghum are some of the better known examples in India. It is also claimed that a large number of cultures among the Assam Rice Collection exhibit a considerably high degree of drought tolerance. Many land races and wild relatives of several crop species are said to contain drought resistant traits, which could be profitably utilised in breeding programmes. This situation is not unique to India alone but is a common experience in different parts of the world. However, to afirm a conviction a short questionnaire to assess the current state-of-art on breeding for drought resistance was distributed to 75 distinguished plant breeders and plant physiologists all over the world. The questionnaire and a summary based on the responses is as follows:

Expression of genetic potential for growth and yield of a crop variety is directly dependent upon the environment comprising both climate (weather) and soil components. As discussed in the preceding chapter, the term ‘salt-affected soils’ encompasses a broad group of adverse but distinct soil conditions, namely, saline, alkali (sodic) and acid soils with further variations such as coastal and inland locations as well as arid and water-logged situations (Swaminathan 1977; Bresler et al. 1982). Factors limiting growth and yield of crop plants in various categories of problem soils are different and specific. Likewise, adaptive strategies evolved by plants to cope with the prevailing edaphic stresses, such as salt stress, also vary a great deal as indicated in Table 1. It is not unexpected therefore, that even varieties within a crop often show notable differences regarding tolerance to adverse soil conditions (Epstein et al. 1980; Devine 1982; Shannon 1984; Sayed 1985). Hence, it is essential that the breeder must understand the inherent charaderistics of the problem soil with which he is concerned and should also simultaneously appreciate that basically it is the sensitivity of crop variety, rather than the soil parameters per se, that essentially determines the occurrence as well as the magnitude of actual soil problem (Rana 1977). Since the degree of tolerance (adaptation) of crop varieties to different kinds of salt affected soils is genetically controlled, it is axiomatic that it can be improved through genetic manipulations by adopting suitable breeding procedures.

Introduction

Accumulation of excess soluble salts in the root zone of soils resulting in partial or complete loss of soil productivity is a worldwide phenomenon. The problems of soil salinity are widespread in the arid and semi-arid areas but salt-affected soils also occur extensively in the sub-humid and humid climates particularly in the coastal regions where the ingress of sea water through estuaries and rivers and through ground water movement causes large scale soil and water salinisation. Soil salinity is also a serious problem in areas where ground waters of high salt content are the only source of water available for irrigation. By far the most serious problems of salinity are being faced in the irrigated, arid and semi-arid regions of the world. Our ability to manage salt-affected soils and waters both in the irrigated and in the unirrigated regions will constitute a major effort in meeting potential food requirements. The magnitude of the problem can be appreciated from the following.

Nanotechnology, which deals with understanding and control of matter at dimension of roughly 100 nm and below, has a cross sectoral application and an interdisciplinary orientation. At this scale, the physical, chemical and biological properties of materials differ from the properties of individual atoms and molecules or bulk matter, which enable novel applications. Nanotechnology research and development is directed towards understanding and creating improved materials, devices and systems that exploit these properties as they are discovered and characterized

There are many applications of nanotechnology such as in the area of medicine, chemistry and environment, energy, agriculture, information and communication, heavy industry and consumer goods. The alleged potential of this technology has garnered the attention of both developed and developing countries across the globe. The US National Science Foundation (NSF) has listed it as one of six priority areas; it is one of the themesin the EU Framework Program for Research and Technological Development in Europe; and it has been the focus of research in countries worldwide.

Nanotoxicology is the study of the toxicity of nanomaterials. Because of quantum size effects and large surface area, nanomaterials have unique properties compared with their larger counterparts

Nanotoxicology is that branch of bionanoscience, which deals with the study and application of toxicity of nanomaterials. The nanomaterials, even when they are made of inert elements like gold, become very active at a nanometer range. Nanotoxicological studies are intended to determine whether and to what extent these may pose a threat to the environment and to human beings. For instance, Diesel nanoparticles have been found to damage the cardiovascular system in a mouse model.

Human health and safety

Calls for tighter regulation of nanotechnology have occurred alongside a growing debate related to the human health and safety risks associated with nanotechnology. The Royal Society identifies the potential for nanoparticles to penetrate the skin, and recommend that the use of nanoparticles in cosmetics be conditional upon a favorable assessment by the relevant European Commission safety advisory committee. Andrew Maynard also reports that ‘certain nanoparticles may move easily into sensitive lung tissues after inhalation, and cause damage that can lead to chronic breathing problems’.

The societal implications of nanotechnology are the potential benefits and challenges that the introduction of novelnanotechnological devices and materials may hold for society and human interaction. The term is sometimes expanded to also include nanotechnology’s health and environmental implications, but this article will only consider the social and political implications of nanotechnology.

As nanotechnology is an emerging field andmostof its applications are still speculative, there is much debate about what positive and negative effects that nanotechnology might have.

Beyond the toxicity risks to human health and the environment which are associated with first-generation nanomaterials, nanotechnology has broader societal implications and poses broader social challenges. Social scientistshave suggestedthatnanotechnology’s social issues should be understood and assessed not simply as “downstream” risks or impacts. Rather, the challenges should be factored into “upstream” research and decision making in order to ensure technology development that meets social objectives.

Over the past few decades, the fields of science and engineering have been seeking to develop new and improved types of energy technologies that havethe capability of improvinglifeall over the world. In order to make the next leap forward from the current generation of technology, scientists and engineers have been developing Energy Applications of Nanotechnology. Nanotechnology, a new field in science, is any technology that contains components smaller than 100 nanometers. For scale, a single virus particle is about 100 nanometers in width.

An important subfield of nanotechnology related to energy is nanofabrication. Nanofabrication is the process of designing and creating devices on the nanoscale. Creating devices smaller than 100 nanometers opens many doors for the development of new ways to capture, store, and transfer energy. The inherent level of control that nanofabrication could give scientists and engineers would be critical in providing the capability of solving many of the problems that the world is facing today related to the current generation of energy technologies.

People in the fields of science and engineering have already begun developing ways of utilizing nanotechnology for the development of consumer products. Benefits already observed from the design of these products are an increased efficiency of lighting and heating, increased electrical storage capacity, and a decrease in the amount of pollution from the use of energy. Benefits such as these make the investment of capital in the research and development of nanotechnology a top priority.

Nanosensors are any biological, chemical, or sugery sensory points used to convey information about nanoparticles to the macroscopic world. Their use mainly include various medicinal purposes and as gateways to building other nanoproducts, such as computer chips that work at the nanoscaleand nanorobots. Presently, there are several ways proposed to make nanosensors, including Top-down and bottom-up design, top-downlithography, bottom-upassembly, and molecular self-assembly.

Predicted applications

Medicinal uses of nanosensors mainly revolve aroundthe potential of nanosensors to accurately identify particular cells or places in the body in need. By measuring changes in volume, concentration, displacement and velocity, gravitational,electrical, and magneticforces, pressure, or temperature of cells in a body, nanosensors may be able to distinguish between and recognize certain cells, most notably those of cancer, at the molecular level in order to deliver medicine or monitor development to specific places in the body. In addition, they may be able to detect macroscopic variations from outside the body and communicate these changes to other nanoproducts working within the body.

The impact of nanotechnology in the food industry has become more apparent over the last few years with the organization of various conferences dedicated to the topic, initiation of consortia for better and safefood, along with increased coveragein themedia. Several companies which were hesitant about revealing their research programmes in nanofood, have now gone public announcing plans to improve existing products and develop new ones to maintain market dominance. The typesof application include:smartpackaging, on demand preservatives, and interactive foods. Building on the concept of “on-demand” food, the idea of interactive food is to allow consumers to modify food depending on their own nutritional needs or tastes. The concept is that thousands of nanocapsules containing flavour or colour enhancers, or added nutritional elements (such as vitamins), would remain dormant in the food and only be released when triggered by the consumer.24 Most of the food giants including Nestle, Kraft, Heinz, and Unilever supportspecific research programmes tocapturea share of the nanofood market in the next decade.

The definition of nanofood is that nanotechnology techniques or tools are used during cultivation, production, processing, or packaging of the food. It does not mean atomically modified foodor foodproduced by nanomachines. Although there are ambitious thoughts of creating molecularfood using nanomachines, this is unrealistic in the foreseeable future. Instead nanotechnologists are moreoptimisticabout thepotential to changethe existing systemof food processingand to ensure the safety of food products, creating a healthy food culture. They are also hopeful of enhancing the nutritional quality of food through selected additives and improvements to the way the body digests and absorbs food. Although some of these goals are further away, the food packaging industry already incorporates nanotechnology in products.

Nanomedicine is the medical application of nanotechnology. The approaches to nanomedicine range from the medical use of nanomaterials, to nanoelectronic biosensors, and even possible future applications of molecular nanotechnology. Current problems for nanomedicine involve understanding the issues related to toxicity and environmental impact of nanoscale materials.

Nanomedicine research is receiving funding from the US National Institute of Health. Of note is the funding in 2005 of a five-year plan to set up four nanomedicine centers. In April 2006, the journal Nature Materials estimated that130 nanotech-based drugsanddeliverysystems were being developed worldwide.

Nanotechnology has the potential to revolutionizethe agricultural andfood industry with newtools forthemoleculartreatmentof diseases, rapid disease detection, enhancing the ability of plants to absorb nutrients etc. Smart sensors and smart delivery systems will help the agricultural industry combat viruses and other crop pathogens. In the near futurenanostructured catalysts will beavailable which will increase the efficiency of pesticides and herbicides, allowing lower doses to be used. Nanotechnology will also protect the environment indirectly through the use of alternative (renewable) energy supplies, and filters or catalysts to reduce pollution and clean-up existing pollutants.

Infrared spectroscopy (IRspectroscopy) is the spectros copy that deals with the infrared region of the electromagnetic spectrum, that is light with a longer wavelength and lower frequency than visible light. It covers a range of techniques, mostly based on absorption spectroscopy. As with all spectroscopic techniques, it can be used to identifyand study chemicals. A common laboratory instrument that uses this technique is a Fourier transform infrared (FTIR) spectrometer.

The infrared portion of the electromagnetic spectrum is usually divided into three regions; the near-, mid- and far- infrared, named for their relation to the visible spectrum. The higher energy near-IR, approximately 14000–4000 cm^–1 (0.8–2.5 μm wavelength) can excite overtone orharmonic vibrations. Themid-infrared, approximately 4000– 400 cm^–1 (2.5–25 μm) may be used to study the fundamental vibrations and associated rotational-vibrational structure. The far-infrared, approximately 400–10 cm^–1 (25–1000 μm), lying adjacent to the microwave region, has low energy and may be used for rotational spectroscopy. The names and classifications of these sub regions are conventions, and are only loosely based on the relative molecular or electromagnetic properties.

Infrared spectroscopy exploits the fact that molecules absorb specific frequencies that are characteristic of their structure. These absorptions are resonant frequencies, i.e. the frequency of the absorbed radiation matches the frequency of the bond or group that vibrates. The energies are determined by the shape of the molecular potential energy surfaces, the masses of the atoms, and the associated vibronic coupling.

A Scanning electron microscope (SEM) is a type of electron microscope that images a sample by scanning it with a high-energy beam of electrons in a raster scan pattern. The electrons interact with the atoms that make up the sample producing signals that contain information about the sample’s surface topography, composition, and other properties such as electrical conductivity.

The types of signals produced by an SEM include secondary electrons, back-scattered electrons (BSE), characteristic X-rays, light (cathodoluminescence), specimen current and transmitted electrons. Secondary electron detectors are common in all SEMs, but it is rare that a singlemachine would havedetectors for allpossiblesignals. The signals result from interactions of the electron beam with atoms at or near the surface of the sample. In the most common or standard detection mode, secondary electron imaging or SEI, the SEM can produce very high-resolution images of a sample surface, revealing details less than 1 nm in size. Due to the very narrow electron beam, SEM micrographs have a large depth of field yielding a characteristic three dimensional appearance useful for understanding the surface structure of a sample.

Electron Microscope

An electron microscope is a type of microscope that uses a particle beamof electronstoilluminate a specimen and createa highly-magnified image. Electron microscopes have much greater resolving power than light microscopes that use electromagnetic radiation and can obtain much higher magnifications of up to 1 million times, while the best light microscopes are limited to magnifications of 1000 times. Both electron and light microscopes have resolution limitations, imposed by the wavelength of the radiation they use. The greater resolution and magnification of the electron microscope is because the de Broglie wavelength of an electron is much smallerthan that of a photon of visible light.

The electron microscope uses electrostatic and electromagnetic lenses in forming the image by controlling the electron beam to focus it at a specific plane relative to the specimen. This manner is similar to how a light microscope uses glass lenses to focus light on or through a specimen to form an image.

X-ray scattering techniquesarea family of non-destructive analytical techniques which reveal information about the crystallographic structure, chemical composition, and physical properties of materials and thin films. These techniques are based on observing the scattered intensity of an X-ray beam hitting a sample as a function of incident and scattered angle, polarization, and wavelength or energy.

Nanoparticle characterization is necessary to establish understanding and control of nanoparticle synthesis and applications. Characterization is done by using a variety of different techniques, mainly drawn from materials science. Common techniques are electron microscopy (TEM, SEM), atomic force microscopy (AFM), dynamic light scattering (DLS), x-ray photoelectron spectroscopy (XPS), powder X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF),ultraviolet-visible spectroscopy and dual polarisation interferometry.

Whilst the theory has been known for over a century (see Robert Brown), the technologyfor Nanoparticle trackinganalysis (NTA) allows direct tracking of the Brownian motion and thismethodtherefore allows the sizing of individual nanoparticles in solution.