eChapters

Bougainvillea is relatively pest-free. Worms, aphids, and moths might be an issue. Sometimes it gets attacked by spiders which can be controlled by using miticide and by the fungus Phytophthora which is checked by spraying Blitox (copper oxychloride) (Sharma 1996, Banerji 2010). Although it is normally pest-free plants, but may suffer from worms, snails and aphids. The larvae of some Lepidoptera species also use them as food plants, for example the giant leopard moth (Hypercompe scribonia). Leaf spot disease caused by Cercosporidium bougainvillea has been reported in the U.S.A. (Sobers and Martinez 1966, Sobers and Seymour 1969). When compared to B. spectabilis, B. glabra has been reported to be resistant or only slightly susceptible to the leaf spot disease (Pal and Swarup 1974). Cercosporidium bougainvillea has been reported in Colombo by Pardo-Cardona (1998) and in Indonesia by Kobayashi and Oniki (1994). The disease can be controlled by spraying copper Carbendazim at the rate of 1 g/l at an interval of 10-15 days. Fusarium wilt caused by Fusarium oxysporum in bougainvillea has been reported in Italy (Polizzi et al., 2010). Bacterial leaf spot caused by Pseudomonas andropogonis has been reported in Brunei, Darussalam (Peregrine and Ahmad 1982, Sivapalan and Hamdan 1997) and U.S.A. (Walker 1991, Walker and Hodge 1991). This can be controlled by spraying copper oxychloride at the rate of 3 g/l at intervals of 10-15 days.

Bougainvilleas is a multipurpose plant due to the variation in habit, growth and colour pattern of different cultivars and are grown as pot plants, standard, hedges, bush, climber, bonsai, landscape, as an espalier, factory gardens, institutional gardens, municipal gardens, terrace garden, wind curtain, topiary, pergola and various other multipurpose. Bougainvillea in an urban landscape trained as a “standard”. It is used as an accent plant, a specimen plant, in hanging baskets, in containers, and for bonsai. Bougainvillea is used to decorate all public, home gardens, play ground and office corridor. About 300 cultivars (150 of which were bred in India) have been derived from 4 species, viz. Bougainvillea peruviana, B. glabra, B. X buttiana and B. spectabilis,through hybridization and natural or induced mutation. Indian-raised cultivars are listed in categories for growing as climbers, bushes, hedges, standards and pot plants and are also grouped under bract colour  (Nagpal 1990, Singh 1990, Singh et al. 2015, Sharma et al. 2015, Kumar et al. 2007, Mathur 2000, 2001, 2007, 2015, Richard and Erin 2002, Simon 2005). It is tolerant to a number of adverse conditions like dry soil, saline soil, pollution etc. Bougainvilleas are sprawling climbers and shrubs. They naturally bloom in the spring and seem to bloom harder in drier years. It is very good plant for desert gardens. It can be used as vines, shaped into bushes, into ground cover. Most suitable for landscaping.  Bougainvillea plants can grow easily on walls. Internode length has a strong influence on bougainvillea growth habit and characteristics in the landscape. They are pollution and drought tolerant and very ideal for landscaping of industrial region as well as for road dividers. They are very hardy plants and specially suitable for growing in rocky and arid areas where other ornamental floweing plants do not  easily thrive well (Fig. 10).

While much has been written about the taxonomy of wild plants, the cultivated plants have always been looked at with suspicion by taxonomists. There might have feeling that cultivated plants are not natural and therefore fall outside the orbit of a taxonomist. It may be that taxonomy of cultivated plants is more difficult due to their extensive distribution needing wide sampling, rampant hybridization and high mutation rate, leading to diversity in their variation patterns. One of the principal advantages of the study of cultivated plants is that more often we know their genetic-evolutionary race history, together with its reasons and diversity. There is, therefore, a need to take up, what may be called as Hortorium Taxonomy, i.e. taxonomy of the cultivated plants so as to put the subject on a proper footing as a prelude to writing a ‘Flora of the Cultivated Plants of India’. The related wild species together with the elemental, basal or parental species of a cultivated species should be classified according to the rule of the International Code of Nomenclature for Cultivated plants based on the cultivar concept. A cultivar is not to be confused with a botanical variety.

Early reports are always path finders for future research. Earlier studies at CSIR-NBRI on characterization of bougainvillea is so important that it should be highlighted for researchers. Horto-taxonomical description of the leading Bougainvillea species/cultivars have been prepared according to their affinities to the species and hybrid seedlings (Sharma 1986a,b, 1996, Srinivas 1995, Khoshoo 1971a,b, Zadoo et al., 1975a, Jayanthi 1999). 
Abraham Kavoor : Bougainvillea x buttiana, tall, vigorous growth, young branches greenish-coppery, leaf blade ovate, green; thorn long, straight; bracts ovate, yellow-orange.
Abhimanyu : B. peruviana, bud sport of ‘Arjuna’, medium, drooping; branch greenish-coppery; leaves variegated, leaf elliptic, green; thorn long, straight, bracts elliptic, red-purple.
Aida : B. spectabilis, hybrid seedling of B. spectabilis (Lancaster 1940, Calcutta), tall, growth vigorous, young stem greenish coppery, tomentose, leaf blade ovate, base acute, apex acute to acuminate, coppery, old dark green, puberulent, thorn straight, bract young carmine changing to rose madder, elliptic, apex obtuse, profuse blooming, ideal as shrub, and pot culture.

The bougainvillea varieties reported from India have been mentioned above. The exact origin of all the varieties are not available. Breeders, sometimes, do not disclose the origin of varieties. An attempt has been made to trace out the mode of origin of different varieties as per available information (Anonymous 1981, Sindhu 2015, Sindhu and Swaroop 2015, Singh 1999, Singh et al., 1999, Nirody 1932, Sharma 1961, 1962, 1963, 1964, 1968, Sharma 1969, Pancho 1963, 1967, Marigowda 1957, Pancho and Elisco 1959, Pancho and Capinpin 1961, Pancho et al., 1961). Information available is not complete in most cases. Following abbreviations have been used – Hybrid Seedling (HS), Bud Sport (BS), Induced Mutant (IM) :

Characterization of Germplasm / Hybrids, Varietal identification, mutants etc.

Accurate identification of plants is desired for patent protection of plant varieties. Accurate characterization is also necessary to trace out the parents of new varieties. Use of present day molecular markers in addition to the classical methods provides more positive identification of new cultivars. RAPD and other molecular techniques have been used in a variety of plant materials for such studies (Sneath and Sokal 1973, Saitou and Nei 1987, Demeke et al., 1992, Selvam and Rajasekaran  1993, 1994, Dubouzet, et al., 1997, 1998, Hallden, et al., 1994, Hu and Quiros 1991, Jain et al., 1994, Matsumoto and Fukui 1996, Williams et al., 1990, Wolff et al., 1995). RAPD technique has been used in the genus Bougainvillea. It is often difficult to distinguish both mutants and hybrids and sports having a common progenitor, or progenitors themselves. Therefore, the industry needs a DNA-based fingerprinting technique to distinguish mutants or cultivars reliably. Reports are available on investigation about the molecular systematics and genetic differences for better understanding of varietal relationships in bougainvillea (Chatterjee et al., 2007, Kumar et al., 2006, Kumar et al., 2014, Hammad 2009, Pavan Kumar et al., 2015). 

Cytogenetics helps in solving intricate problems of evolution of economic plants and their relationship with relevant wild ancestors. Ornamental plants provide very interesting material for evolutionary studies. Such a study would reveal the nature of the evolutionary steps and clarify the changes that the breeding system and chromosomes underwent. The genetic and cytogenetic reasons for the diversity in ornamentals would also be unraveled. Such a study also helps to chalk out a meaningful breeding methodology for genetic improvement. A systematic programme of genetics and plant breeding of ornamental plants was started at CSIR-NBRI. The objectives of the programme were both basic or creative (experimental analysis of the causes of variation and evolution) and applied or productive (experimental synthesis of new and novel variation with better putative parents). Evaluation of colchiploids of ornamentals with different genetic systems was being carried out at CSIR-NBRI, with a view to explore the possibility of their introduction in floriculture trade. Superiority of polyploid cultivars, in general, has been the main factor, which has induced gardeners to raise artificial tetraploids. Most of the garden forms are of hybrid origin, raised over a number of years and named differently by different workers and nurserymen. More often than not, there is no authentic record of their ancestory and they show a great deal of morphological and cytological polymorphism (Khoshoo 1968, 1990, Datta and Banerji (1995). 

For crop improvement and more specifically to develop new varieties a number of plant breeding methods are available. CSIR-NBRI from very beginning selected all available techniques and standardized their practical application for all ornamental crops. All crop specific basic information was collected/generated for successful application of techniques for development of new varieties by creating genetic variability. Ornamental plant species fall into two main categories. In the first group the plants that are capable of sexual reproduction, but are commercially propagated vegetatively. The second group of plant species are the apomicts. In obligate apomicts hybridization fails to generate any variability. For development of new variety creation of genetic variability is pre-requisite. Breeder should have all up-to-date knowledge about all the available techniques and their merits and demerits for improvement and development of new varieties.

Considering the economic importance of chlorophyll variegation in floriculture trade attempt was made for cytological, anatomical and biochemical analysis of chlorophyll variegated mutants for better and clear understanding of origin of chlorophyll variegation (Kirk and Tilney-Bassett 1967, Datta et al. 1995). Following chlorophyll variegated mutants and their respective original varieties were analysed –

‘Los Banos Beauty’ (LBB) : Original double bracted Bougainvillea with green leaf.

Floriculture has become very important industry as a result of science based techniques and steady supply of improved plant materials. One of the major constraints of floriculture industry is non availability of large scale quality planting materials. Conventional methods of propagation can not meet the increasing demand of propagating materials. Micropropagation is perhaps the most widely used biotechnology tool for large scale propagation of floricultural crops. This economic proposition has led to intensive practical research to evolve tissue culture techniques for mass propagation and production of virus-free plant material.  Since most of the ornamental crops are highly heterozygous, their seed progeny is not true-to-type. Conventionally in these plants vegetative reproduction method is followed to produce genetically identical plants at commercial scale. But the main constrain of this method is that only a limited number of plants can be raised in a year from a single mother plant and often fail to meet the market demand. Therefore, most of the modern floriculturists follow the micropropagation technique for rapid multiplication of ornamental plants.

World trade of fresh cut flower is increasing day by day. Fresh flowers lose their freshness and quality both during travel and also during and after arrangements due to flower specific short vase life. Such deficiencies can be ameliorated through application of nutrient additives to vase water. Use of preservative solutions has been known for many years to increase the vase life of cut flowers. Different methods like use of holding, pulsing and bud opening solution, growth regulators, gamma irradiation, pre-cooling, cold storage, packaging etc. are already in practice in the flower trade to ensure the garden fresh quality of flowers to consumers (Singh et al., 2001). The floral business is expanding in a big way, nationwide.  Sales of cut flowers are rising faster through retailers as every state has entered into development of supermarket chains. Cut flower sale through retailers is  a booming business. Retail growers and Wholesale growers are the major players in our country for domestic market. Retail market suffers from logistic bottlenecks. Retailers do not have any background scientific knowledge to increase the vase life of cut flowers. Flower buyers are very choosy and prefer quality bloom with longer vase life.

New varieties of bougainvillea have been developed in India at different research institutions, nurseries, botanical societies and also by individual efforts. Details have been mentioned above. New varieties developed at CSIR-NBRI need special mention. 

CSIR-NBRI has developed a number of new varieties by using various available breeding tools viz. through spontaneous mutation, classical breeding, chromosome manipulation and induced mutation (Banerji 2007, 2008, Banerji and Datta 1986, 1988, 1993, 1996, Banerji et al., 1987, Data and Banerji 1990, 1994a,b, Datta 1992b, 2004, Nath et al., 1983, Ohri 1995, Sharma 1996, Zadoo et al., 1975b, Jayanti et al., 2007, Roy et al., 2015).

There are different crop specific societies in different countries for registering new varieties. This does not provide any intellectual property right. It serves as a documental proof of new variety, author, mode of origin, place and date. For example, there is The American Rose Society which serves as the International Cultivar Registration Authority for Roses; The Royal Horticultural Society, International Registration Authority for the genus Dahlia; Indian Agricultural Research Institute, New Delhi -110 012, India for Bougainvillea. Each society either follows the rules set forth by the International Code of Nomenclature for Cultivated Plants or they are having their own rules and regulations for registration (Anonymous 1981, Choudhury 1973, Singh 1983, 1986, 1987, 1999, Singh et al., 1999, Sindhu 2015, Singh 2007). Newly evolved Bougainvilleas are being registered by the Division of Vegetable Crops and Floriculture, Indian Agricultural Research Institute, New Delhi, since 1966. A check list of all the existing important cultivars based on the available information from literature as well as from amateurs, professional traders and other sources from different countries are available.

As mentioned above Bougainvillea is one of the most widely grown important perennial ornamental shrubs with numerous attractive plant colour (leaf) and shape, and bract colours and shape. It is very popular for its multipurpose use. Inspite of beautiful bract colour it can not be enjoyed as cut flower as its shelf-life is very limited. Bracts start drooping within few minutes after cut from the main plant. Dehydration techniques have been developed at CSIR-N.B.R.I., Lucknow, by which flowers and foliage retain their fresh look for several months or even years after dehydration. Their original shapes, colour and size remain as they were before dehydration and, thus, making them highly suitable raw materials for interior decoration and may be enjoyed for a long time and can be used for any occasion. NBRI has standardized two methods viz. Press Drying and Embedding (drying through embedding in sand and silica gel and drying using hot air oven, microwave oven and solar cooker). Bougainvillea leaves and bracts can be dehydrated beautifully by both the methods and the dried products are utilized for preparation of different types of commercial decorative items. 

Introduction

From the very early days human beings depend on animals and animal products for food and other requirements. In dairy and poultry farms high yielding animals are reared. These high yielding animals are produced by hybridization experiments. Previously the animals were developed basing on unscientific methods. Before the discovery of principles of heredity human beings have selected the animals with required characters and learned to develop the plants having the selected characters. This phenomenon is called Artificial selection. However, an increased knowledge of biology, especially genetics, has helped in improving the quality of animals and animal products as per the human requirements.

Domestication of Livestock

Domestication (from Latin domesticus) is the process whereby a  population  of  animals  or plants is changed at the genetic level through a process of selection, in order to accentuate traits that benefit humans. It differs from taming in that a change in the phenotypical expression and genotype of the animal occurs, whereas taming is simply the process by which animals become accustomed to human presence. In the Convention on Biological Diversity, a domesticated species is defined as a “species in which the evolutionary process has been influenced by humans to meet their needs.” Therefore, a defining characteristic of domestication is artificial selection by humans. Humans have brought these populations under their control and care for a wide range of reasons: to produce food or valuable commodities (such as wool, cotton, or silk), for types of work (such as transportation, protection, and warfare), scientific research, or simply to enjoy as companions or ornaments. Plants domesticated primarily for aesthetic enjoyment in and around the home are usually called house plants or ornamentals, while those domesticated for large-scale food production are generally called crops. A distinction can be made between those domesticated plants that have been deliberately altered or selected for special desirable characteristics and those plants that are used for human benefit, but are essentially no different from the wild populations of the species. Animals domesticated for home companionship are usually called pets while those domesticated for food or work are called livestock or farm animals.

Definition of Breed

A breed is a group of animal’s related similar characters like general appearance, size, features and configuration etc. A group of individual which have certain common characteristicsthat distinguish them from other groups of individuals is known as Species.

There are certain inherited traits (characters) in various species of livestock which are economically important. These traits have to be improved for increased production like milk, meat, egg, wool, etc.

Introduction
Statistics is a field of mathematics that pertains to data analysis. Statistical methods and equations can be applied to a data set in order to analyze and interpret results, explain variations in the data, or predict future data. A few examples of statistical information we can calculate are:
Average value (mean)

Quantitative Versus Qualitative Inheritance

There is a continuum of traits being inherited as a Mendelian trait with simple inheritance and traits having quantitative inheritance without well separated classes and with many genes involved.
Classification of traits in relation to mode of inheritance and environmental tolerance are shown in Figure 1.2. First there are the well known traits with simple Mendelian mode of inheritance. The trait with quantitative genetic inheritance is caused by segregation of many gene pairs, each with small effect. At the same time the trait is influenced by a lot of minor environmental effects.
Diseases will often be ‘either/or traits’ as the simple Mendelian traits. Cases in which the severity of the disease has a normal distribution can also be found. In many production diseases the disease only occurs when a genetically prone individual is exposed to adverse environmental effects. Figure 1. Classification  of traits in relation to mode of inheritance  and environmental tolerance. 
 

Gene Frequency

A population, in the genetic sense, is not just a group of individuals, but a breeding group and the genetics of a population is concerned not only with the genetic constitution of the individuals but also with the transmission of the genes from one generation to the next. In the transmission the genotypes of the parents are broken-down and a newest of genotypes is constituted in the progeny, from the genes transmitted in the gametes. The genes carried by the population thus have continuity from generation to generation, but the genotypes in which they appear do not. The genetic constitution of a population, referring to the genes it carries, is described by the array of gene frequencies, that is, by specification of the alleles present at every locus and the numbers of proportions of the different alleles at each locus. If for example, A1 is an allele at the A locus, then the frequency of A1, is the proportion or percentage of all genes at this locus that are the A1 allele. The frequencies of all the allele at any one locus must add up to unity, or 100 percent. 

The amount of variation is measured and expressed as the variance. When values are expressed as deviations from the population mean the variance is simple the mean of the squared values. For example, the genotypic variance is the variance of genotypic values and the environmental variance is the variance of environmental deviations. The total variance is the phenotypic variance of the variance of phenotypic values, and is the sum of the separate components. 

The concept of value, expressible in the metric units by which the character is  measured. The value observed when the character is measured on an individual is the phenotypic value of that individual. All observations of means, variance, or covariances, must clearly be based on measurements of phenotypic values. In order to analyse the genetic properties of the population we have to divide the phenotypic value into two componants. 
The first division of phenotypic value is into components attributable to the influence of genotypic and environment. The genotype is the particular assemblage of genes possessed by the individual, and the environment is all the non-genetic circumstances under the term ‘environment’ means that the genotype and the environment are by definition the only determinants of phenotypic value. The two components of value associated with genotypic value and the environmental deviation. 

Estimates of heritability use statistical analyses to help to identify the causes of differences between individuals. Because heritability is concerned with variance, it is necessarily an account of the differences between individuals in a population. Heritability can be univariate–examining a single trait – or multivariate – examining the genetic and environmental associations between multiple traits at once. This allows a test of the genetic overlap between different phenotypes: for instance hair colour and eye colour. Environment and genetics may also interact, and heritability analyses can test for and examine these interactions (GxE models).

In genetic studies it is necessary to distinguish two causes of correlation; is chiefly pleiotropy, though linkage is a cause of transient correlation, particularly in populations derived from crosses between divergent strains. Pleiotropy is simply the property of a gene whereby it affects two or more characters, so that if the gene is segregating it causes simultaneous variation in the characters as affects. For example, genes that increase growth rate increase both stature and weight, so that they tend to cause correlation between these two characters. The degree of correlation arising from pleiotropy expresses the extent to which two characters are influenced by the same genes. But the correlation resulting from pleiotropy is the overall, or net, effect of all the segregating genes that affect both characters. Some genes may increase both characters, while others increase one and reduce the other the former tend to cause a positive correlation the latter a negative one. So pleiotropy does not necessarily cause a detectable correlation. The correlation resulting from environmental causes is the overall effect of all the environmental factors that vary; some may tend to cause a positive correlation, others a negative one.

Selection is an important tool for changing gene frequencies to better fit individuals for a particular purpose. It may be defined as a process in which certain individuals in a population are preferred to others for the production of the next generation. Selection is of two kinds

The response to selection is the change produced in the population mean through selection. This is achieved through selecting as parents of the next generation, individuals with highest genetic merit and whose progeny will, as a group, have the highest possible genetic merit for the trait in question. 

Individuality tells us what an animal seems to be; his pedigree tells us what he ought to be, but the performance of his progeny tells us what he is
Effectiveness of selection depends on ability to recognize those animals, which possess superior inheritance. Those superior animals must be mated together for the production of offspring. The aids available to estimate the breeding value of an animal is through the phenotype of an animal or its relatives.

An animal breeder usually interested in various economic traits and when wishes to improve them in the herd/flock, he has three general methods at his disposal. Tandom method, independent culling level method and  index selection method.

Tandom Method

It involves selection for one trait at a time and until it reaches at a satisfactory level, and then for a third trait etc. This method is applicable only when the different traits in question are entirely independent or positively genetically associated to each other. Its effectiveness decreases with the increase in number of traits. This method is least desirable of all the methods.

Open nucleus breeding system is considered to be a best approach to bring genetic improvement in livestock. This system was first introduced New Zealand for faster genetic improvement of sheep. The milk recording under field condition is quite expensive.  Moreover, farmers are not under any obligation to retain the animal till the lactation is completed.  The generation interval is also very large as it takes about 6-7 year by the time complete record on progeny testing programmes in developing countries is available, so that the effective genetic improvement is small.  Use of best proven bull on the elite cow, which are best 5-10% of the cow for genetic improvement of the population. The net genetic gain in the herd considering the actual genetic improvement from various parents off spring path is around 0.7% per annum.  Considering these situation in develop countries it has been proposed that ‘nucleus’ herd be created where males from the best cows are obtained.  The nucleus herd would be open in the sense that the lowest yielding cows are culled every year and are replaced by procurement of that many high yielding cow from farmers herd.  The nucleus herds are utilized entirely for production of males for breeding purposes in the population.

Progeny testing in India was introduced in the late 1950’s the first sire index in our country was suggested by Krishnan (1956) which was, however, similar to the herdmate and contemporary comparison methods. Robertson and Rendel (1954) stated that an efficient method of sire evaluation should satisfy two conditions: 

The aim of mating systems are either to increase or decrease the homozygosity of the progeny compared with the parents or in some cases, to maintain the degree of homozygosity unchanged. This aim constitutes the basis of the following classification of mating systems:

Heterosis, hybrid vigor, or outbreeding enhancement, is the improved or increased function of any biological quality in a hybrid offspring. The adjective derived from heterosis is heterotic.Heterosis is the occurrence of a superior offspring from mixing the genetic contributions of its parents. These effects can be due to Mendelian or non-Mendelian inheritance.

General Selection Procedures for Dairy Breeds
Selection of Dairy Cows
Selecting a calf in calf show, a cow in cattle show by judging is an art. A dairy farmer should build up his own herd by breeding his own herd. Following guidelines will beuseful for selection of a diary cow. Whenever an animal is purchased from cattle fair, it should be selected based upon its breed characters and milk producing.
History sheet or pedigree sheet which are generally maintained in organized farmsreveals the complete history of animal.The maximum yield by dairy cows are noticed during the first five lactations. So generally selection should be carried out during First or Second lactation and thattoo are month after calving.?Three successive complete milkings has to be done and an average of it will givea fair idea regarding production by a particular animal.
A cow should allow anybody to milk, and should be docile.?It is better to purchase the animals during the months of October and November.?Maximum yield is noticed till 90 days after calving.

Cattle Breeding Policies and Programmes in the Planning Process

It is necessary to see how the issues relating to Cattle Breeding have been dealt with in the successive Plan periods starting from the First Five Year Plan. It is seen that, while the issue of surplus cattle has been handled in different ways in the various Plan documents, some discussing this issue at great length and other remaining completely silent on the subject, other issues such as cattle development, genetic improvement and breeding etc., have also received varying degrees of emphasis in the different Plans. 

Introduction
India has vast animal genetic resources with a wide variety of indigenous farm animals including cattle. The cattle breeds have evolved over generations to adapt to the agro-climatic and socio-economic needs of the people. Domestic animal diversity is defined as the spectrum of genetic differences within each breed and across all breeds within each domestic animal species, together with the species differences; all of which are available for the sustainable intensification of food and agriculture production. The domestic animal diversity has evolved over millions of years through the processes of natural selection forming and stabilizing each of the species used in food and agriculture. Over the more recent millennia the interaction between environmental and human selection has led to the development of genetically distinct breeds. Selection processes, directed by both humans and the environment, together with the random sampling processes causing genetic populations to drift over generations, have accelerated the development of the diversity within species leading to the creation of distinct genetic differences amongst breeds.

The cashew nut (Anacardium occidentale L.) belongs to Anacardiaceae family which also includes the mango, pistachio and poison ivy (Nakasone and Paull, 1998). Anacardium contains 8 species all of which are native to the coastal parts of north eastern Brazil (Azam-Ali and Judge, 2001). Cashew nut tree provides food, employment, income and the wood is used for carpentry mainly in the construction of boats and ferries while other products derived from it include firewood and charcoal (Akinwale, 2000). Cashew resins are also used in the manufacture of insect repellents and natural insecticides, while different tree parts have medicinal value as they are used to cure various diseases (Cavalcante et al., 2003). The cashew tree is a sprawling broad-leafed evergreen, well adapted to poor soils and dry sandy locations, drought resistant, but grows best on well drained sandy soils with pH of 4.5 to 6.5 (Aliyu, 2004). It favours temperatures between 15 to 35°C and rainfall over 400 mm with elevation of up to 1000 m above sea level.

Cashew has a long history as a useful tree but only in the current century, it became an important tropical horticultural crop. Small-scale local exploitation of cashew for its nuts and cashew apples is the pattern for more than 300 years in Asia and Africa. It was not until early years of 20^th century that international trade in cashew kernels began with first exports from India. Although with slow beginning, cashew became an important commercial crop in the last couple of years. In India, use of cashew apples and nuts was started by local people, and accounts from Africa are similar; making cashew wine/liquor possessing a common practice in both Asia and Africa (Johnson, 1973).

Cashew, an evergreen tree, produces both nuts and apples, has become a crop of importance owing to the highly valued kernel and wide adaptability to varying agro-climatic conditions. India is one of the largest producer, exporter and consumer of cashew in the world. Today, cashew has become a crop of high economy and has moved from a crop of waste lands to commercial crop, even in organized sector (Singh, 1998).

Global Scenario

Globally, India’s share in the cashew area and production is 20 per cent and 16 per cent, respectively. India occupies the largest area followed by Ivory Coast (19%), Brazil (16%), Indonesia (12%), Vietnam (7%), Nigeria (7%), Benin (5%), Guinea-Bissau (5%), Mozambique (2%) and Philippines (1%). The highest production was from Vietnam (30%) followed by Nigeria (19%), India (16%), Ivory Coast (11%), Brazil (5%), Indonesia (3%), Philippines (3%), Guinea-Bissau (3%), Benin (2%) and Mozambique (2%). Sometimes back, India was credited as largest producer, processor and exporter of cashew in the world but as other cashew producing countries also acquired the know-how of processing and entered in the international market, currently the India’s share in the International market has shrank to 30 per cent only. On the other hand, the domestic consumption in India has increased considerably, owing to largest consumption of cashew kernel. Every year, over 7-8 lakh tonnes of raw cashew nut are imported mainly from African countries and exporting cashew kernel to USA and UK after processing (Saroj, 2013).

Soil
Cashew is grown on a wide variety of soils in India. It comes up well in all types of soils at an altitude up to 700 m. It cannot stand in water logged or saline soils. It can come up in very sandy soils also. Adoption of cashew has been found in wide variety of soils from coastal sands to degraded laterites. The worst soils, not suited to other crops, are normally allotted for cashew. In Sri Lanka and Philippines, it is grown in alluvial soils. Cashew comes up well even in volcanic soils of Indonesia, Fiji and some part of Philippines. Cashew is not suitable in heavy clays, water logged conditions and ill drained soils. It is grown abundantly in loose sandy soils particularly in South India, East Africa and Brazil. In Karnataka and Kerala, it grows well in poor laterite soils. Cashew prefers well-drained aerated sandy loam soils with adequate moisture. Coastal plains and plateau are very good for cashew cultivation.

In India, cashew is mostly grown on laterite and red soils and coastal sands. The tree has an extensive root system, which helps it to tolerate a wide range of moisture levels and soil types, but commercial production is only advisable in well-drained, sandy loam or red soils with slight acidic pH (4.5-6). The cashew tree can flourish in the sand of open beaches, but it grows poorly in heavy clay or limestone.

Though cashew can be grown on a variety of soils, a well-drained 1-1.5 m deep soil having a water table between 2 and 10 m depth and pH of 5.6 to 7.0 is preferred. Laterites, red and coastal soils rich with organic matter are best for cashew growing. Even the marginal soils can be used for cashew cultivation but the waterlogged condition should be avoided as the cashew is very susceptible to it (Farooki and Sreeramu, 1999).

Anacardium occidentale is a medium-sized tree, spreading, and evergreen, much branched; grows to a height of 12 m. When grown on lateritic, gravelly, coastal sandy areas, it rarely exceeds 6 m and develops a spreading habit and globose shape with crown diameter to 12 m but, if grown inland on loams; it reaches 15 m tall and is much branched, with a smaller (4-6 m) crown diameter. The root system of a mature A. occidentale, when grown from the seed, consists of a very prominent taproot and a well developed and extensive network of lateral and sinker roots. Leaves simple, alternate, coriaceous, glabrous, obovate, rounded at ends, 10-18 x 8-15 cm, with short petiole, pale green or reddish when young and dark green at mature. Rai and Vatsala (1985) studied the dermal morphology and stomatal ontogeny of Spondias pinnata Kurz., Lannea coromandelica (Houtt.) Merr., Anacardium occidentale L., Holigarna arnottiana Hook. F. and Mangifera indica L. are studied. The cuticle is thick in H. arnottiana, A. occidentale and M. indica, but is thin in S. pinnata and L. coromandelica. Based on the shape of epidermal cells, the five species are categorised into three: cells in both upper and lower epidermis sinuous (A. occidentale, H. arnottiana, S. pinnata); upper sinuous and lower polygonal (M. indica) and upper polygonal and lower sinuous (L. coromandelica). Stomatal ontogeny aperigenous (L. coromandelica), paramesoperigenous (A. occidentale) and anisomesogenous (M. indica, H. arnottiana). S. pinnata is peculiar in that it possesses three different types of stomata, aperigenous, hemiparamesoperigenous and paramesoperigenous; whereas, in all the other four species, only one type of stomatal ontogenesis exists. Except S. pinnata, all the other species possess epidermal appendages. Unicellular trichomes occur in A. occidentale and H. arnottiana, and multicellular glandular trichomes in A. occidentale, M. indica and L. coromandelica. The multicellular hairs are found in A. occidentale in specialized pockets in two rows on either side of the major veins - a unique feature which is reported for the first time.

Cashew research in India dates back to 1950’s when Indian Council of Agricultural Research sanctioned ad-hoc schemes in the then composite Madras, Travancore, Cochin and Bombay States. Thus, Kottarakkara (Kerala) in 1952; Ullal (Karnataka in 1953 and Vengurla (Maharashtra) in 1957 came into being as pioneering cashew centres in the country. More research schemes were started with ICAR’s assistance in 1955 at Bapatla (Andhra Pradesh) and in 1956 at Deragaon (now shifted to Kothiali) in Assam. During the period, Central Food Technological Research Institute, Mysore and National Chemical Laboratory, Pune were also engaged in developing technologies for economic utilisation of cashew apple and Cashew Nut Shell Liquid (CNSL). In the second phase of strengthening cashew research in India, the ICAR started All India Spices and Cashewnut Improvement Project in 1971 linking countrywide network among different research centres. Collection, conservation and evaluation of germplasm, hybridization and selection, vegetative propagation, and nutritional studies were the primary areas under this programme.

Maharashtra, the first state was to release cashew variety under the name Vengurla-1 through Dr. Balasaheb Sawant Konkan Krishi Vidyapeeth, Dapoli in the year 1974. So far, 8 varieties have been released from Regional Fruit Research Station, Vengurla (M.S.), of which, Vengurla-4, Vengurla-6, Vengurla-7 and Vengurla-8 are widely accepted for commercial plantation.

Cashew being a highly cross pollinated crop, planting of seedling is not recommended. In the past seed propagation was in vogue, which has resulted into large variation in plants due to highly heterozygous nature. However, it is seldom practiced now-a-days except to raise the rootstock materials. Selection of seed is very important for raising rootstock material. Seed nuts which are heavy and sink in water should be selected for raising seedling. Seed nuts should be collected from high yielding trees. Seed nuts collected from the current season’s crop during March, April and May are the best for seed production as they have been found to give high percentage of seed germination. Studies conducted to investigate the time taken and germination percentage revealed that heavy nuts (sunken in water) gave 92 per cent germination on 14-17 days, whereas floating nuts took 14-22 days and gave 64 per cent germination (Krishnamurthy et al., 1985).

Pattern of Growth Flushes in a Bearing Tree

Two or three peak periods of growth are usually observed in a bearing cashew tree, even though under favourable conditions the stray shoot growth may occur almost every month. The pattern of growth of a bearing tree consists of a generative flower flush (reproductive) and a vegetative flush. The vegetative flush, consisting of lateral shoots, always develops soon after the main crop has matured. Flowering is terminal and is universally preceded by the vegetative flush.

There are two types of branching in cashew, intensive and extensive.

The emasculation and pollination in any crop depend on its floral structure and biology. Cashew is basically andromonoecious (polygamo monoecious) crop with staminate and hermaphrodite flowers appearing in the same inflorescence or panicle (Rao and Hassan 1957). The hermaphrodite/bisexual/perfect and male flowers occur intermediately in the same panicle in three or four phases viz., Male – Mixed – Male or Mixed – Male – Mixed– Male. Distinct phases depend on genotype and environmental factors. The tree shows considerable variation in the duration of different phases. The hermaphrodite flowers are bigger in size than staminate or male flowers (Damodaran et.al., 1965). Male flower always exceed the bisexual flowers. The flowers produced early in a panicle are mostly male (Rao and Hassan 1957; Damodaran et. al., 1965). Most of the perfect flowers are produced about one month after the first flower occurred in the panicle (Bhat et al., 1998).

Selection of Site and Land Preparation

Cashew is a hardy plant; it thrives well on wide range of soil. While selecting the land for cashew, soils with water logging and excessive salinity of alkalinity should be avoided. Otherwise, soil depth, slope, stoniness, soil fertility and water availability seem to impose very little limitation. For establishing new plantations, land preparation should begin with the first pre-monsoon rains. The area should be cleared of bushes and other wild growth before digging pits for planting.

Planting Season

Planting of soft wood grafts is usually done at the beginning of monsoon season (June-July). Therefore, land preparation such as clearing of bushes and other wild growth, digging of pits for planting, should be done during pre monsoon season (April-May).

Various studies have demonstrated that the cashew tree responds to the application of mineral nutrients, though the responses are significantly affected by plant age, the genotype utilized, the conditions of cultivation, soil and climate and of the crop management (Barros et al., 1984; Ghosh, 1990; Ximenes, 1995; Bezerra et al., 1999; Crisóstomo et al., 2005). The crop develops well under semi-arid conditions, in which the problems associated with water availability and salt excess in the root environment are common. These two factors interfere with the acquisition of nutrients, in that the levels of nutrients in the plants are affected both by direct effects on absorption and transportation processes and by indirect effects associated with a reduction of growth of the various plant organs including the root system. The effect of salinity on plant nutrition depends on the types of salts that predominate in the cultivation environment which can result in a deficiency of essential nutrients and an excess of toxic ions. These changes under salt stress are accompanied by a loss of structural and functional integrity of the cellular membranes, a reduction in activity of various vital enzymes, and a diminished capacity of the roots to absorb nutrients (Zhu, 2001). On the other hand, water deficit reduces the extraction of nutrients from the soil, limiting the solubilization of nutrients in the root environment and altering the morphology of the root system (Kramer and Boyer, 1995). It should be added that the effects of excess salt and water deficit depend on various factors, including the species under study and the stage of development at which the plants are submitted to these.

Canopy management is the manipulation of tree canopies to optimize the production of quality fruits. The canopy management, particularly its components like tree training and pruning, affects the quantity of sunlight intercepted by trees, as tree shape determines the presentation of leaf area to incoming radiation. An ideal training strategy centres around the arrangement of plant parts, especially, to develop a better plant architecture that optimizes the utilization of sunlight and promotes productivity. Light is critical to growth and development of trees and their fruits. The green leaves harvest the sunlight to produce carbohydrates and sugars which are transported to the sites where they are needed – buds, flowers and fruits. Better light penetration into the tree canopy improves tree growth, productivity, yield and fruit quality. The density and orientation of planting also impact light penetration in an orchard. Generally, in close planting, quicker shading becomes a problem. An east-west row orientation results in more shading as compared to the western and southern orientation of trees. Strong bearing branches tend to produce larger fruits. The problem of a fruit grower is initially to build up a strong and balanced framework of the trees, then equip them with appropriate fruiting. Obviously, pruning in the early years has to be of a training type to provide strong and stocky framework with well spaced limbs or any other desired shape.

Pruning in young tree during initial stage help to form a strong frame work for better growth and development of the tree. However, on long term way, the tree becomes huge with gigantic canopy results in to problem of majority of agronomic operation, plant protection and harvesting of crop. Top working provides an opportunity to control the growth of tree and makes the tree productive with manageable canopy, in old and senile orchards.

Top working is a technique evolved to rejuvenate the unproductive and senile cashew trees. Poor yielding trees of 5-15 years of age can be successfully rejuvenated by top working. The unproductive trees are to be headed back to a height of 1.00 m from the ground level in October-November. The stem should be sawed off to avoid stump splitting. Soon after beheading, the stumps and cut portions should be given a swabbing with carbaryl 50% WP (50 g each per litre of water) or Bordeaux paste. Sprouts emerge 30-45 days after beheading. Sprouting will be profuse in young trees. So, it is better to keep only 4-6 healthy shoots on beheaded tree spreading in all directions and similarly the sprouts which come out from ground level (most probably water shoots) also removed frequently. On 30-45 day old shoots, graft scions of high yielding varieties following soft wood grafting technique. On each tree, 4-6 grafts are to be done to ensure at least 3-4 successful grafts per tree. The best season for grafting is March-April. Thinning of the extra shoots arising from the stumps should be done to obtain better growth of the grafts. Removal of sprouts below the graft joint and removal of polyethylene strip from the graft joint should be done. Top working is simple and can be done by farmers themselves after getting proper training. The top worked trees start yielding right from the second year of top working. Early bearing can be treated as one of the best advantages of this technique. The major disadvantage associated with top working is the huge casualty of trees due to stem borer attack. Intensive care and management to ward off stem borer is essential. As such adoption of top working on a larger scale would be difficult.

In the field of agriculture/horticulture, various irrigation systems are being employed to fulfil the water requirement for better growth and development of the tree. Since, cashew is hardy plant which can sustain in rainfed conditions of warm and humid region; it has very good potential to produced higher nut yield. Of the various irrigation methods, drip irrigation system is best method in the areas where natural resources of water is limiting factor. It is well known fact that this system has many advantages.

During the first year after planting, protective irrigation is recommended at 15 days interval during winter and at 8 days interval during summer season. At each irrigation, 25 litres of water to be given per graft. The studies on mulching and irrigation were under taken with a view to determine fruit retention. It was observed that black polythene mulch with irrigation @ 60 liter of water per tree at 15 days interval showed beneficial effect on increasing fruit retention (66.15%) over control. Cashew is grown under rainfed conditions. However, supplementary irrigation during summer months, especially during January-March at fortnightly intervals @ 200 litres/plant proved to double the yield. This is evident from the research results obtained at NRC-Cashew, Puttur (Karnataka).