eChapters

INTRODUCTION

Cashew nut (Anacardium occidentale L.), in the current global scenario, has attained the status of economically important crop with considerable export potential. Ancient sea route traders have been responsible for the spread of cashew from Brazil, its native, to other parts of tropical and sub tropical regions. In the rainforest areas with hot and humid regions of North east Brazil that the people from the long past knew to roast and use the cashew kernels. The owning of cashew trees meant the wealth, prosperity and social status of the family even in those days around 1500 AD in Tropical American region. The commercial importance of cashew nuts was not aggressively known at the time of its initial introduction into Asian and African countries.

INTRODUCTION

Sapota [Manilkara zapota (L) P. Royen] commonly known as chiku in India, is an exotic fruit crop originated in Tropical America. The name sapodilla is derived from the Spanish word zapotilla, meaning “small sapote.” Tree have dark green beautiful radiating canopy with central flag having aesthetic values.It is a popular crop widely cultivated in most tropical countries. The cultivation of sapota is a profitable venture as it does not need much spraying, pruning and it is a long-life fruit tree. Moreover, the fruit fetches good price in market as it ripens in April and May in North India, when mango and litchi fruits are scarce. At international level in India crop attained an important place in fruit industry. In India this fruit species is cultivated only for its delicious fruit for table purpose but in South America, it is cultivated for chickle the “gutta parcha” which is used as base material for chewing gum.This is extracted from bark. Sapota fruit present a climacteric behavior. In India farmer from Bordi village near Gholwad, late Sri Gopal Rao Patil realized the commercial potential of this evergreen and ever fruiting tree and procured a few plants and began to propagate for distribution among poor farmers of this area and within short time it had spread from Palghar in Maharashtra to Amalsad in Gujarat. Subsequently commercial cultivation in his region was helped by lranis and Marwari settlers. The best sapota orchards in this area belong to lranis and Marwaris. It is from this area that this fruit went to various other parts of the country like Andhra Pradesh, Tamil Nadu, and Karnataka, Punjab and Haryana etc. In India crop become very popular among farmers as a cash crop. There is a possibility of extending cultivation of this crop into warm and humid climate of all tropical regions of the world. In India area under this crop increasing every year. Therefore, in recent years, it has attained the status of major fruit in peninsular India. Popularity of this fruit is on increase due to high production per unit area and continuous fruiting throught out the year.

INTRODUCTION

Pineapple [(Ananas comosus (L.) Merr., Bromeliaceae)] is a commercial, tropical American crop, popularly known as “Golden Queen” all over the globe. The name ‘pineapple’ was given in the mid-17th century because of its resemblance to ‘pine cone’. Its botanical name Ananas comes from ‘anana’, the Tupi word for the fruit, meaning “excellent fruit” and comosus means tufted and refers to the stem of the fruit.
 
Pineapple is a monocotyledonous, low-growing,herbaceous and perennial with a spiral of spiny sword-shaped leaves on a thick stem. It has 90 to 100 cm height with spreading leaves, which give the plant a rosette appearance.The plant bears a single fruit terminally on a peduncle protruding out from the centre of the rosette. The fruit is mostly a large juicy fruit containing aromatic, edible, yellow flesh surrounded by a tough segmented skin and topped with a tuft of stiff leaves.

INTRODUCTION

Papaya (Carica papaya L.) is known as wonder fruit of the tropics. It is unique plant, which produces fruits throughout the year. It owes its popularity due to various reasons, i.e., requires less area per tree, comes to bearing in a year, easy to cultivate and has high nutritive and medicinal value. Papaya is an ideal fruit for growing in kitchen gardens, backyard of homes as well as in orchards, especially those near the cities or big towns. India ranks first in production of Papaya in the world with share of 31% of the total production. Its productivity is highest (43.70 t/ha) among the fruits grown in. It is also  India. It is famous intercrop due to its small stature, short life cycle, precocious in bearing and grown extensively as a filler crop in orchards.
 
Papaya is quick growing, bearing fruits within 8-10 months of transplanting and giving yield in same year. Fast growth with high photosynthetic rate, reproductive precocity, low production cost and more output characterize the uniqueness of this fruit. Now a day, the area under this crop is growing rapidly due to its higher productivity. Indeed, papaya cultivation is very profitable if done on modern lines. Demand for its fruits is growing in domestic as well as export markets and require modern technological interventions for commercial exploitation of these fruits. A ready market for its fruits becomes a big bonus for growers. Immediate availability of a selling point and a good price from a buyer encourage the farmers to grow more papaya crop.

INTRODUCTION

Guava (Psidium guajava L.) is an important fruit crop of India. It is a tropical fruit but also grows well under sub-tropical conditions. Guava is one of the commonest fruits liked by all the people and is known as ‘Apple of Tropics’. It is one of the major fruit of India and considered the fifth most important fruit in area and production after mango, citrus, banana and apple. Guava is quite hardly, prolific bearer and highly remunerative fruit which needs relatively less care as compared to other fruits. It excels most of other fruit crops in productivity and food value and as such has wide adaptability to soil and climatic conditions. Guava is such a fruit which is practically grown all over the country on commercial scale and especially in kitchen gardens and near the tubewell premises. The best quality of guava in India is grown in the area around Allahabad. Guava bear heavy crop every year and offer handsome economic return to growers.

INTRODUCTION

Banana (Musa species) also known as ‘Apple of Paradise’ is an important and commercial fruit crop of tropical regions of the world. It is the only tropical fruit traded to the extent, that it is the 5th largest agricultural commodity after cereals, sugar, coffee and cocoa in world market.

The word ‘banana’ is now applied to all table varieties. Formerly, it was applied to ‘Nendran’ banana of Kerala which was however called ‘Plantain’ by Westerners. The English used the word ‘Plantain’ to represent cooking banana while in parts of South India, even sweet fruited clones were called ‘Plantains’. The variant with persistent bracts and male flowers with large fruits held in lax manner and eaten after cooking were grouped under plantains. All other types which had small fruits, held compact in a bunch with softening of the pulp when ripe, dropping of withered bracts and staminate flowers as the banana. In other words plantain are starchy, not sweet and cooked as vegetable. They usually resembles green bananas, are longer and have thick skin. Bananas are sweet, shorter and have thinner skin. They are eaten as a fruit and have yellow colour when ripe.

INTRODUCTION

Mango (Mangifera indica L.) belonging to Family Anacardiaceae is the most important commercially grown evergreen tree of tropical and subtropical regions of the world. Due to its wide range of adaptability, high nutritive value, colorful fruits, richness in variety, delicious juicy taste and excellent flavor, it possesses high commercial value. It is sometimes also called ‘apple of the tropics’. It is believed that cultivation of mango originally started in South East Asia where it is being cultivated for last four to six thousand years. Now, it is cultivated in 112 countries of the world. India has the richest collection of mango cultivars.

INTRODUCTION

As per National Horticulture Database published by National Horticulture Board, during 2014-15 India produced 89.15 million metric tonnes of fruits. This value however differs from the consumption value depending upon the post harvest losses, storage losses or transportation losses. Transportation and distribution of fruits being the most important factor, plays a key role in determining the net income from horticulture trade. It is an essential link in the modern food chain and exists as complex matrix where not only fresh goods finished products are transported but there is also transportation of bulk raw materials. Locally grown produce may be transported directly from farms to retail outlet. For local market, the produce is brought by bullock cart, tractor, trollies. Mainly the long distance transportation is by trucks, rails which is costly. In India the transportation by Railway is much less than the other means. The road transport is 3-4 times more expensive than rail, yet it is preferred for shipment of fresh fruits simply because of the faster movement of perishable commodities.

INTRODUCTION
 
Once a crop is harvested, it is almost impossible to improve its quality. Therefore, proper storage conditions—temperature and humidity—are needed to lengthen storage life and maintain quality once the crop has been cooled to the optimum storage temperature. In modern times, the storage of perishables has become more sophisticated because of the demand for a wide range of fresh fruits and vegetables at all the times of the year and because of need to spread peaks of production over longer periods to maximize profit and reduce waste. But in our conditions, storage of fruits and vegetables is practiced to avoid the low prices during the glut season in anticipation that prices will increase during the lean period or off-season. Certain crops like potatoes and apples can be stored for long period whereas for the crops peach and plum, the storage period is very short. However, for both long-term as well as short-term storage, high level of technical know-how about the crop is necessary for successful storage. There are a few important factors, which need to be taken into account before storage of the produce.

In post-harvest management of horticultural crops, post-harvest treatments play an important role in maintaining the quality and enhancing the shelf life. There are number of treatments viz non-chemical, chemical and biological treatments which are being used commercially depending on the requirement of trade. Fresh fruits are living tissues subject to continuous change after harvest. Some changes are desirable from consumer point of view but most are not. Post-harvest changes in fresh fruit cannot be stopped, but these can be slowed down within certain limits to enhance the shelf life of fruits
 
1. Low Temperature Treatment

Pre-cooling: Pre-cooling refers to the rapid removal of field heat from freshly harvested fruits in order to slow ripening and reduce the deterioration prior to storage and transportation. The major effect of pre-cooling consists in reducing respiration rate, retarding the growth of decay organisms and reduces wilting and shrivelling, since transpiration and evaporation occur more slowly at low temperature. The harvesting of many perishable crops is done at evening or early morning to avoid excessive field heat.

Grading is defined as sorting of fruits into different grades according to the size, shape, colour, and volume to fetch high price in market. Grading of fruits after harvesting is an essential step in post-harvest management. Grading of fruits is done on the basis of physical characteristics like weight, size, colour, shape, specific gravity and freedom from diseases. The known methods of grading of fruits and vegetables are manual grading and size grading. Sizing produce is usually a part of grading and is optional for direct marketers, but may be worthwhile if certain size grades receive a higher price than others. Round produce units can be easily graded by sizing rings. Several types of mechanical sizers are available for small-scale operations. Sorting by maturity can maximize the market value of crops such as stone fruits and mangoes .The grades of different fruits suggested by Directorate of Marketing and Inspection (DMI) are given in Table 1.

INTRODUCTION

Fruits of commercial importance comprise various combinations of tissues that may include an expanded ovary, the seed and other plant parts such as the receptacle (apple, strawberry), bract and peduncle (pineapple). They may develop from a single ovary of a flower as in simple fruits (apple, banana, mango, peach, plum, tomato etc.), number of ovaries of a single flower as in aggregate fruits (strawberry) or from a number of ovaries of different flowers as in compound fruits (pineapple). They are derived from members of a wide range of families of both monocotyledonous and dicotyledonous plants. Inspite the huge diversity in origin, structure, composition and climate adaptabilities that exists among different fruits, there is considerable similarity in the pattern of maturation and ripening that occur in different fruits.

INTRODUCTION

With the change in world scenario from plentiful resources to limited with population increasing geometrically, shrinking land and climate change, the pressure on agriculture is mounting continuously. Meeting the nutritional requirements of population by optimum supply of food is the pre-requisite for sustainability of life under such conditions. Rapid urbanization is causing scarcity of cultivable land. Therefore, the productivity per unit area of the crops needs to be increased manifold. Horticulture, in general, has attained a pride status in the field of modern agriculture. However, radical changes are expected in horticultural practices in near future as the situation in terms of area as well as production is not as comfortable as the food grain production.

INTRODUCTION

The initial care of young seedlings and propagated plants is very necessary and important. Efforts should be made in such a way that the young plants can be propagated and grown to a saleable size with no insect-pests and diseases attack and nutrient deficiency. The supply of healthy plant material to the growers helps in good reputation of a nursery as well as to make fruit crops more profitable.

Sometimes young nursery plants suffers from various problems like attack of insect-pests and diseases, nutrient deficiency, scanty or excessive moisture and stagnation of excess or rain water in the field. The young seedlings/plants require light and frequent irrigation and need special care to make them grow well and to save them from adverse weather conditions. They must be protected from intense heat and cold. The young nursery plants growing on light or sandy soils can exhibit deficiency symptoms of macro and micro elements. Such nutrient deficiencies can easily be corrected by foliar or soil application of desired nutrient.

INTRODUCTION

For survival of young seedlings and rooting of cuttings it is essential that they maintain a healthy water and air balance especially to make up the water lost in transpiration. Water stress within the cuttings hinders metabolic activities and cell regeneration and consequently initiation of roots. So medium should be such that it provides adequate water required for rooting and growth. Also these substrates must provide initial nutrients necessary for plant growth. These should also contain micro-organisms that seedlings may need.

SEED GERMINATION

Germination is the growth of a plant contained within a seed; it results in the formation of the seedling, it is also the process of reactivation of metabolic machinery of the seed resulting in the emergence of radicle and plumule. The seed of a vascular plant is a small package produced in a fruit or cone after the union of male and female reproductive cells. All fully developed seeds contain an embryo and, in most plant species some store of food reserves, wrapped in a seed coat. Some plants produce varying numbers of seeds that lack embryos; these are called empty seeds and never germinate. Dormant seeds are ripe seeds that do not germinate because they are subject to external environmental conditions that prevent the initiation of metabolic processes and cell growth. Under proper conditions, the seed begins to germinate and the embryonic tissues resume growth, developing towards a seedling.

INTRODUCTION

Plant tissue culture is basically in vitro culturing of any type of explants such as leaf, root, bud and stem or even single cell except the seed or embryo on a suitable culture medium under controlled environmental conditions. Plant tissue culture employs the totipotency of plant cells to produce whole plant. The term totipotency was coined by German plant physiologist, Haberlandt (1902) who is known as father of tissue culture techniques.

Definition of Micropropagation

Micropropagation is one of the best and most successful examples of commercial application of tissue culture techniques. The concept of micropropagation was first presented to the scientific community in 1960 by Morel, who produced the virus-free cymbidium through meristem culture. It entails in vitro propagation of plants starting with very small plant parts (0.2-10mm) grown aseptically, followed by their establishment in soil under green house conditions. It is the art and science of plant multiplication in vitro. This technique has been standardized and commercialized for various fruits and vegetable crops.

INTRODUCTION

Plant propagation involves three main aspects: knowledge of mechanical manipulations and technical skills which constitutes the art of propagation; knowledge of plant growth and structures which constitutes science of propagation and knowledge of different kinds of plants and their methods of propagation. The basic objective of plant propagation is to increase the number of desirable types and to preserve the essential characteristics of the plant. Generally, sexual propagation or the seed propagation is used to raise the seedling rootstocks on which to graft or bud the desirable types. The clonal rootstocks are multiplied through vegetative means- layering, cutting etc. Various sexual and asexual methods such as use of seeds, apomicts, specialised plant parts, cuttings, layers, grafts and buds are employed to multiply plants of different fruit crops. In this chapter, the techniques used for raising rootstocks and multiplying the desirable types of different fruits have been discussed.

INTRODUCTION

The propagation of plants has been one of the fundamental occupations of mankind since beginning of civilization. Plant propagation involves the application of specific biological principles and concepts in the multiplication of plants for useful purposes. The present day plant propagation industry is large and complex and involves not only the group that multiplies the plants for sale and distribution, but also a large group of industries that provide services, sell the product, is involved in regulation, provides consultation carries on research or is involved in teaching. The key person with in this complex, however, is the plant propagator who possesses the knowledge and skill either to perform or to supervise the essential propagation tasks for specific plants.

INTRODUCTION
 
Growth and development are often used interchangeably, however, these describe separate events during the life cycle of a plant. To understand these precisely, let us take the example of multicellular organisms like annuals, monocarpic or flowering plants (angiosperms) including fruits, vegetables, flowers etc. which begins their life from a single cell fertilized egg, the zygote. The zygote develops into embryo through the cell division and differentiation. When we sow the seed in garden or pots, in a few days a young seedling emerge. With the passage of time, the seedling grow in size, the number of leaves increases, in perennial plants branching occurs for few years, and after putting forth the requisite vegetative growth plant begins flowering, produces fruits, seeds and finally the plant senesce at certain period. Generally three terms “growth”, differentiation” and “development” are used to describe the different events during the life cycle of a plant.

INTRODUCTION

Plant growth regulators (PGR) are bioactive molecules that modulates the physiological processes in plants and are effective at ultra-low concentrations. Minute alteration in the concentration and bioactive forms of PGRs’ throughout the plant development phases regulate the flowering, fruit set and development. The use of plant growth substances to control fruit set, size, shape, and maturation has become important in agriculture today because they have the ability to increase fruit size, colour, and shape, thereby increasing the marketability. By hastening or delaying maturation the grower can utilize peak demands, avoid unfavourable environmental conditions, and extend the market period. PGRs are applied in fruit crops at all developmental stages for various purposes as discussed below: 

INTRODUCTION

Water is one of the most important inputs essential for tree growth, development and fruit production. Fruit trees need it continuously during their life in optimum quantities. It profoundly influences photosynthesis, respiration, absorption, translocation and utilization of mineral nutrients, and cell division besides some other processes. Both its shortage and excess affect the growth and development of a plant directly and, consequently, its yield and quality. In India, however, rainfall is notoriously capricious, causing floods and droughts alternately. Its frequency distribution and amount are not in accordance with the needs of the particular fruit crops. Artificial water supplies through irrigation on one occasion, and the removal of excess water through drainage on another occasion, therefore, become imperative, if the fruit crops are to be raised successfully. Water management in India, thus, comprises irrigation or drainage or both, depending considerably on the environmental conditions, soil, crops and climate. Applying the proper amount of water at the right time is important for reducing costs and maximizing profits. It is essential, therefore, that there be a scientifically sound method for determining when to irrigate and how much water to apply for optimum crop response and efficient use of resources.

INTRODUCTION

The chemical compounds needed for growth and metabolism in plants are termed as nutrients. Mineral nutrition of fruit plants is a vital soil management practice in an orchard. The nutrients are converted to cellular constituents or used for energy purposes through metabolic process. Broadly the essential plant nutrients may be divided into macro-nutrients and micro-nutrients. Macro nutrients are needed in plants in relatively higher amounts than micronutrients.
 
Macro nutrients: C,H, O, N, P, K, S, Ca, Mg. 
Micro nutrients: Fe, Mn, Cu, Zn, Mo, B, Cl, Ni.
 
Altogether 17 elements are considered essential for normal growth and production of a plant.While elements like cobalt, sodium and silicon have been established as essential elements for some plant species and not all. C-H-O matrix accounts for over 90% of the dry matter and is usually 20 to 50% of the fresh weight of the whole plant. Chloride is a most unusual nutrient as it is often present in plants in high concentrations yet its essential requirement is very much lower. Chlorine like Na and K plays an important role in osmoticum. The nutritional needs of fruit trees can be assessed through leaf and soil analysis, tree growth and cropping, and past experience.

INTRODUCTION
Canopy management is one of the most important management practices in an orchard. It is the ‘art’ of fruit growing involving manipulation of tree canopies to optimize the production of quality fruits. In fact it forms the basis of precociousness, productivity and longevity of the fruit trees. Canopy management is an important aspect of fruit culture due to its effect on yield, quality, vigour, and the prevention of diseases.
 
In orchard, light is critical to the 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, yield and fruit quality. Training and pruning, affects the tree shape and facilitate exposure of leaves to sunlight. 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. Besides, development of strong scaffold system helps the trees to produce heavy crop loads of quality fruits without any major limb breakage.

INTRODUCTION

Soil is one of the most important factors associated with the success or failure of fruit production. Orchard soil management refers to those practices in the soil that aim at getting maximum productivity/production of quality fruits within the limits of soil, water and fertility management over the years. The decision regarding the practices of orchard management should always be taken well in advance before planting of an orchard. The practices for orchard management should be executed in a timely manner during the lifetime of the orchard. An efficient orchard management system always ensures higher return to the grower. However, no single management practice can be recommended for all orchards. The management systems varies from orchard to orchard, locality to locality, soil to soil, from one set of climatic conditions to another set of climatic conditions etc. These systems also have their own merits and demerits. Thus the choice of best suitable system depends on many factors such as climate, topography, rainfall, tree spacing, planting system/ orchard design, root depth of tree, economic condition of orchardists, fertility status of soil and type of main fruit crop etc.However, it should be combined with pruning, nutrient and water management, provision for pollination, fruit thinning and disease and pest management in order to obtain desirable tree growth and vigour with the aim to promote precocity with high productivity. The objectives of an ideal soil management system should be:

INTRODUCTION

The planning of new orchard is very important aspect of fruit glowing which needs special attention and care to make it more profitable venture. The climate and soil of particular area are the major chief natural factors in the orchard establishment. The proper combination of this governs the success of fruit growing
 
A. SUITABILTY OF CLIMATE FOR FRUIT PLANTS

Climate refers to an average condition of the atmosphere over a long period, whereas, the term weather refers to the current and temporary atmospheric conditions of an area. Climate is the principal factor for optimum vegetative and reproductive growth of plants. The success or failure of crop in a particular locality depends upon the prevailing climatic conditions. In our environment it is fundamental force which includes various components of climate like temperature, humidity, wind, light, rainfall, hail and frost. These factors should be taken care of for successful fruit production. All cultivated crops including fruit crops have certain natural threshold limits of the climatic parameters for their normal growth. The important climatic components which affect fruit crop production are given below:

A. PLANNING OF AN ORCHARD

Orchard is a long-term investment and needs proper planning and layout before establishment. Mistakes committed during planning and planting of fruit trees cannot be rectified. While planning and planting a new orchard, it is very important to carefully assess all the factors that will ultimately affect fruit yield and orchard sustainability. The aspects like location and site selection, suitability of soil and subsoil, suitability of fruit crop and varieties, plant spacing, market potential and source of nursery plants must be taken care of seriously. Thus, one should avail of expert advice on the establishment of new orchards and their proper maintenance.

INTRODUCTION

The climate of India is favourable for production of a variety of tropical, subtropical and temperate fruits. The area under cultivation, production and productivity of fruit crops has increased significantly during the last fifteen years. Horticulture has emerged as major area of growth in the agricultural sector and has out performed other crops with respect to production and productivity. The increase in fruit production was improved considerably from 43.0 million tonnes in 2001-02 to 91.4 million tonnes in 2015-16 (Table 1). This increase in production has come from an increase in area under different fruit crops and overall increase in productivity. In this way, India has maintained its second rank in global production of fruits next only to China. The fruit area increased from 4 million hectares in 2001-02 to 6.4 million hectares in 2015-16. On the basis of fruit production, it is estimated that per capita fruits availability in India 190 g per day which is still less than the recommended quantity of 230 g per capita per day.

Q.1.    What is the most fundamental assumption to be followed by random variable for using the standard method of parametric statistics or parametric inference ?

    Answer
    
    The most fundamental assumption required to be followed by random varibale for using the parametric statistics to have statistical inference drawn from certain set of data is that the random variables have normal distribution.

Preliminaries and Test Based on N. P. Lemma
    
More on Testing of Hypothesis

Method of Maximum Likelihood Estimation (M.L.E.)
    
Method of Moments
    
Method of Minimum X²
    
Interval Estimation

Preliminaries
    
Minimum Variance Unbiased Estimator and Cramer, Rao Inequality
    
Minimum Variance Unbiased Estimator (M.V.U.E.) and Black Wellisation
    
Results on UMVUE and MVUE
    
Efficiency and Consistency
    
Consistency
    
Sufficiency and Completeness
    
Distribution Possessing Sufficient Statistics
    
Sufficient Statistic for Several Parameters
    
Completeness of a Sufficient Statistic
    
Some Important Results in Theorem Forms
    
Minimal Sufficient Statistic
    
Results on Complete Sufficient Statistic

Q.1.    Under what situation, the exact sample tests are required to be used and who discovered it first time ?

Test for Significance for Population Mean
    
Test for Significance of Population Proportion

Q.1.    In what sense the analysis of covariance is an extension of ANOVA ?

    Answer
    
    The analysis of covariance is an extension of ANOVA in the sense that it covers the case where observations are taken on more than one variable from each experimental unit. The interest centers on the study variable y which depends upon on auxillary variable x.

Q.1.    What is progeny row trial ?

    Answer
    
    The replicated experiment designed to compare a number of parent plants with respect to any characteristic under study is known as progeny row trial.

Q.1.    Define strip plot design ?

    Answer
    
    There is a variant of the split plot design in which both factors A and B will be applied to the larger strips by dividing the experimental field into as many rows as the number of levels of one factor A and into as many columns as the number of levels of second factor B. Then the two factors will be applied at random to the rows and columns. Such a layout is known as strip plot design.

Q.1.    What is split plot experiment ?

    Answer
    
    If one has to study two type of factors say A and B in the same experiment where A requires larger plot size and B requires smaller plot size then the structure of the experiment will be that of plots within blocks are known as split plots and blocks within replication are known as main (whole) plots. Such a layout of the experiment is known as split plot experiment.

Preliminaries
    
Results on 22 Factorial Experiment
    
23 Experiment in r Replication
    
Confounding

Partialy Balance Incomplete Block Design (PBIBD)
    
Interblock and Intrablock Information

Analysis of Variance
    
Completely Randomised Design (C.R.D.)
    
Randomised Block Design (R. B. D.)
    
Latin Square Design

Q.1.    What is an experiment ?

    Answer
    
    An experiment is a means of getting an answer to the question that an experimentor (researcher) has in mind. This may be to decide which of the several pain relieving drugs that are available in the market, is the most effective or whether they are equqlly effective.
    
    An experiment may be planned to compare the yield of different varieties of wheat. so that the varity giving the maximum yield may be recommended to the farmers to increase their production.

The choice of hormones and drugs acting on reproductive system are important as therapeutic agents during reproductive disorders like anoestrus, metritis, pyometra, repeat breeder, retention of fetal membranes, delayed puberty, ovarian disorders etc.  The administration of specific chemotherapeutic agent is of paramount importance in treating reproductive disorders in dairy animals.  The dosage, route, frequency and indications of chemotherapeutic agents acting on reproductive system are mentioned in tabular form as below.

Reproductive process involves many events that have to occur in a well balanced manner if satisfactory fertility rate is to be achieved. Any adverse  effect of  physiological, morphological  or environmental effect on the male  or  female may result  in failure  of  fertility  or reduced fertility  depending  on the severity of the cause. Apart from this, the role of person who stands between the cow and the bull play an important role. The efficiency of the person handling the semen and depositing in the reproductive tract of domestic animal will influence to a great extent on the conception rate in A.I. programme. It is observed that certain bovine population fails to conceive at a single service or series of services.   Some times there is loss of conceptus during gestation or produces a dead calf or weak calf that will die soon after birth.
 
Consequences of these factors affect cows and may have long calving interval, abortion or sterility, all of which tend to decrease the average daily production of milk.

The various steps involved in frozen semen technology are vital as the quality of semen determines the conception rate.  The key factor enabling the successful long term storage of frozen spermatozoa is maintenance at ultra low temperature.  Effective semen storage depends heavily on good identification and stock control.  Frozen semen can be easily damaged in the process of repeated handling to establish identity.

Several cryogenic agents have been used in many countries for freezing and preservation of bovine semen like solid carbon-di-oxide (-79°C), liquid air (-183°C), liquid helium (-268°C) and liquid nitrogen (-196°C).  Liquid nitrogen is 4th coldest substance known and its small amount is converted into a very large amount (near about 700 times) of its volume when exposed to atmosphere.  It is a colourless, odourless, non-irritant, non-toxic, non-caustic, non-corrosive, non-inflammatory and inert gas having boiling point -196°C temperature.  Being a liquid it comes into good contact with the surface of the semen straws and constant storage temperature is maintained throughout the straw and due to these properties LN2 is most widely used refrigerant in the world.

There is no rapid direct test to determine fertility of semen sample. During freezing and thawing of semen 20-80% of the spermatozoa become immotile or die. In addition to this, there may be damage to spermatozoa by disintegration of sperm cell membrane and acrosome leading to loss of intracellular enzymes.   The only reliable method to evaluate the semen is to inseminate a cow and get a calf at the end of gestation period.  Now-a-days new methods have been developed for in-vitro assessment of fertility of spermatozoa.  Some of these methods are exhaustive, time consuming, need for a full fledged analysis and difficult under field conditions.

Production is based on reproduction and health of reproductive system. Economy of livestock industry is directly attached to the maintenance of high fertility in the herd so controlling the reproductive diseases in cattle is a must.  Reproductive health may be disturbed by reproductive infections like Brucellosis, Leptospirosis, Infectious bovine rhinotracheitis and Bovine viral diarrhea.

A typical repeat breeder cow or buffalo is an apparently normal cycling cow / buffalo with normal genitalia which has failed to settle to services or inseminations during three or more consecutive estrus periods. These animals can neither be considered as sterile nor can settle to subsequent services.  Age of the repeat breeder should not have exceeded beyond 12 years.

The causative factors for repeat breeder animals fall in two main categories as failure of fertilization and early embryonic death.