eChapters

The decline of productivity and health of the tress may be due to faulty management i.e. unsuitable site and climate, cultivation of intercrops, inadequate nutrition, improper planting, undesirable planting materials, incidence of insect pest and disease and other biotic and a biotic stresses. The decline of trees are characterized by sparse appearance, yellowing and different type foliage symptoms, undergrowth and sickly appearance, dried-up top growth with small and less number of fruits. The branches of trees start to die from the top to downwards, ultimately resulted poor quality fruits. Such type of decline may be seen in whole orchards, on in a single tree or patches. Senile orchards with poor productivity are now a common problem in temperate, tropical and subtropical fruits. Since most of the fruit trees has long juvenile period, hence going for replanting, rejuvenation may be better option to convert sick tree into productive ones.

Diseases are often the most important constraint to the production of different fruit crops. They directly or indirectly reduce yields by debilitating the plant, and depleting the fruit quality. They range from aesthetic problems that lower the marketability of the harvested product to lethal problems that devastate the overall production. Virtually all fruit crops are affected by one or more serious diseases. Diseases determine how and where a crop is produced, what postharvest treatments are utilized, in what markets the crops are sold, and whether production is sustainable and profitable. Hence, as a fruit crop student one should know have the knowledge of different diseases occurring on major fruit crops, their symptoms and management strategies;

Management system adopted for fruit trees are quite different, especially with regard to nutrient than that adopted for field crops. The shift in management system could be commenced 3-4 years after planting depending on the tree size. Nutrients are required for flowering and fruiting while at the same time trees are allowed to grow and maintain sufficient vigour for producing high yields in following years. To maintain productivity of trees in long run and maintain the sustainability of tree production capacity, application of nutrient should be based on actual requirement and availability of nutrient in the soil. Application of plant nutrients economically at correct time with right amounts in a way that nutrients could be taken up by plants efficiently with minimum losses. The purpose of assessment of nutrient requirement of fruit trees is to keep mineral nutrient levels in the tree with in the desired range to have the growth and development effects and fruiting of trees as desired.

The most important thing in nutrient management for bearing trees is to analyze the importance of timing of nutrient application in relation to tree phenology or growth cycle.

Determination of Specific Gravity

The palatability of the citrus fruit is associated with its internal quality. Measuring specific gravity provide clues to internal quality of the fruit. The ratio of the weight of the fruit to its submerged weight indicates specific gravity. Specific gravity also indicates relationship between fruit weight and volume.

Steps: To determining specific gravity

Record the weight of fruit in air on top loading balance.

Losses resulting from pre harvest and harvest drop of fruits have long been a serious problem to the fruit growers. As the fruits of some species and varieties approach the picking maturity, they tend to loosen from the stalk and considerable quantities may drop prior to and during the picking operation. Such fruits are badly damaged and if salvaged have a very low value compared with those picked from the tree. In certain fruit crops, the problem of fruit drop is very serious. Whereas in some, the fruit drop starts right from the time of fruit set and is severe at a number of stages of fruit development. In some fruit crop serious drop occurs before harvest.

Maturity indices and their adoption at harvesting and in post harvest management of fruits provide a information against quality loss, microbial decay and deterioration of external appeal. Fruit harvesting at proper stage of maturity has direct effect on quality and market value of produce. Stage of harvesting also influence the after harvest enzymatic activities of the horticultural produce, which determines the levels of different pigments, sugars, acids and vitamins in fruits, flowers and vegetables. Maturity can be described as the attainment of a particular size, stage after which ripening takes place. However, horticultural maturity is defined as the stage of development when a plant or plant part possess the prerequisites for utilization by consumers for a particular purpose. Cucumbers, lettuce and peppers are harvested at various stages (Horticultural maturity) prior to reaching physiological maturity, or completion of growth phase.

There are many methods to determine produce maturity. The most common is the size of the individual commodity.Some other commonly used crude methods are colour change, Softening of the tissues (fig,sapota) ease of detachment from the stalk (Sapota, annona), shrivelling of fruit stalk (water melon), time elapsed from the date of flowering to picking maturity, sound by tapping jack and water melon when ripe produce hollow and dull sound on tapping but produce metallic sound if unripe etc. Another physical characteristic is the firmness and it is determined with a pressure tester. Firmness is often correlated with chemical changes that occur during ripening. Chemical characteristics include TSS, acidity, sugar, vitamins and pigments. There are certain test which accurately gives the maturity measurements such as use of colour charts (judge colour), penetrometers (firmness), brix: acid ratio etc. Other recent methods viz. thermal conductivity X-rays and NIR have also come in practice to judge the maturity of fruits and vegetables. Some commonly use maturity indices are given below in some of the important fruits.

Alternate bearing (AB) or biennial bearing (BB) is a major challenge to growers and traders of fruit crops. It is typically initiated by an abnormally heavy crop in trees (on year), followed by a light or no subsequent crop (off year).When on and off year sequence does not follow a systematic pattern it is called periodicity of cropping or irregular bearing. Alternate bearing is assigned due to genetic factor while irregular bearing may be due to lack of good orchard management practices. Alternation becomes entrained and difficult to change unless severe climatic events intervene, or drastic management interventions are made. A heavy “on” crop results in reduced vegetative shoot and root flushing, and less carbohydrate (energy reserves) build-up. Phenomenon of alternation is more prominent in the perennial fruit crops particularly in Anacardiacae (mango and pistachio), Carylaceae (Hazelnut), Oleaceae (olives), Rosaceae (apple, pear, plums, apricot etc), Rutaceae (orange, Tangor, Satsuma etc) and also tamarind, jamun etc. fruit crops. Within a tree species some cultivars are regular while others are alternate bearer e.g. in mango Amrapali is regular while Langra is strongly alternate bearer.

Water is an important input in crop production. It acts as solvent, reactant and used for transpiration and maintaining cell turgidity. Hence, knowledge of soil moisture is essential for making irrigation scheduling. For determining soil moisture status, the commonly used methods and instruments are discussed along with their advantages and disadvantages. The soil moisture can be measured by determining either the soil water content or the soil water potential. The measurement of soil water content is an estimation of the mass or volume of water in the soil, while the soil water potential is an expression of the soil water energy status. The relation between content and potential is not universal and depends on the characteristics of the local soil, such as soil density and soil texture. We can measure soil moisture content both by direct and indirect methods. In direct method, we remove the water from the soil sample by evaporation and the amount removed is determined. This method is popularly known as gravimetric method. We measure property of soil that is affected by soil water content under the indirect methods. Indirect methods employ tensiometric, nuclear (neutron and gamma radiations), electromagnetic (radar and time domain reflectometers), hygrometric (electrical resistance, capacitance, Infrared absorption) techniques besides remote sensing for making soil water models. In the following paragraphs both the methods of soil water measurement has been discussed.

Training and pruning are an important activity in fruit crops to have better frame work and optimum fruiting area. Training refers to giving a desired shape to the plants by tying or staking or supporting over a structure and or selective pruning for a good strong frame work. Pruning refers to cutting of certain portion of plants for maintenance of fruitfulness and quality besides vigour of the trees or vines. Pruning affects the functions of the plants and assists in better fruiting and in getting more quality fruits. It is one of the most crucial operations and require some scientific knowledge regarding bearing behavior of the plants.

There are several planting plans or systems which can be adopted for planting an orchard. The main principle for the layout of orchard is:

1. It should accommodate maximum number of plant per unit area.
2. Provide adequate space for the development of the tree.
3. Ensure convenience in orchard operations.

The various lay out systems used are the following

Plant Growth Regulator (PGR) are diverse group of organic compound other than nutrients, produced artificially or by plants which in low concentrations promote, inhibit or modify the physiological process in plant. Among the PGRs produced by plants are auxins (indole-3-acetic acid and its derivatives), gibberellins, cytokinins, abscisic acid and ethylene.

Application of certain plant growth regulators promotes the process of seed germination, and development of roots in cuttings and layers. Various growth regulators have been used with striking success. Of these auxins such as indole3-acetic acid (IAA), indolebutyric acid (IBA) and naphthalene acetic acid (NAA) have the greatest effect on root formation in cuttings and layers. These chemicals speed up the healing of the wound, induce more roots and their development. They are now used universally in the propagation of many fruit plants. The growth regulators are effective in minute concentration and are usually applied in dilute solutions and dust formulations or rarely in grease bases such as lanolin. Plant growth regulators are generally calculated in the form of parts per million (ppm) or microgram per gram (mg/g).

The packing methods practiced by nurserymen for transport of nursery plants to distant places in India are neither uniform nor efficient. In different parts of the country, various practices are followed which are claimed to have been evolved by long experience of the local nurserymen. They vary according to nature of the plant, the season and the cheapest packing material available at the time of packing.

In many parts of the country, citrus nurserymen uproot plants, tie them in large bundles (with or without soil), keeping the plant tops exposed to air and roots tightly packed or tied in the gunny cloth. The pomegranate and guava plants prepared by air layering are packed as such if they are not already potted in small pots.

Many nurserymen pack the rooted or newly lifted plants in a ball of sticky clay. The ball of earth is then covered with grass and tied as firmly as possible, thus securing the roots against drying. A number of plants, thus prepared, are filled closely in light locally knit bamboo baskets. The baskets are covered thinly with coconut leaves as protection against injury during railway shipment. Mango grafts in pots are packed in light baskets with some cushion of grass to reduce the impact while loading and unloading the parcels on their long journey by rail and road.

Some nursery men use large baskets, woven out of coconut leaves with limp walls or sides. Plants such as coconut, chikoo, guava, mango are packed tightly in these baskets and shipped by truck or rail. This packing is done irrespective of plant containers such as pot or a ball of earth, with or without grass covering. The plants packed in all such fashions are usually damaged and some of them do not survive, unless care is taken during or after transplanting them in the permanent places. For better success, it should be seen that the roots of grown up plants do not get irreparable injury while removing from the bed or the pot. During transport, loss of water by transpiration should be kept at minimum, while the plants are awaiting dispatch or delivery at the railway platform, precaution should be taken against pilferage or damage by animals.

What is Nursery?

Nursery is a place, where seedlings, samplings, trees and other plant material are grown and maintained until they are planted in permanent place. Setting up of a horticultural nursery is a long term venture and needs proper planning for good return.

Establishment of Nursery

To be a viable venture, the nursery should be established in such an area where cultivation of fruit crops is on sizeable area and there is need for a nursery, having demand for saplings. In such area/region, following considerations need to be observed for selecting an appropriate location.

Rootstocks play an important role in the propagation of plants. It may modify form or stature, adapt a variety of a soil, fit in an incompatible climate, impart or resist disease to the scion, increase production, hasten maturity of crop, change the colour of the fruit, effect the flavour of the fruit, shorten life of the tree, increase the size of the fruit, develop vigour, effect salt tolerance and influence storage capacity.

The propagation of plants has been one of the fundamental occupations of mankind since civilization begins. Most of the selected plant would have lost or could have attained undesirable forms if they were not propagated under strict environment conditions. Growth, in all nature, result from the division of cells to form more similar cells. Thus bacteria reproduce by simple division, in higher plants and animals, a new individual is genetically formed only when cell division fallows the fusion of two cells. This is known as sexual reproduction. There are thus two methods of producing new plants, sexual and asexual or vegetative reproduction.

I. Sexual Propagation

Raising of plants by means of seeds is called sexual propagation. There are many plants raised for our garden from seeds. The plants produced through seeds are called seedlings. In sexual method, the sex organs of flower are involved in process like pollination and fertilization, resulting the formation of seeds. eg rootstocks plants of many fruit crops are grown through seed propagation.

1. Mango

Varieties released from I.A.R.I., New Delhi

Malliaka: (Neelum x Dashehari)

This variety was released in 1971. Tree moderate, semi-vigorous to vigorous, moderate spreading, bearing moderately and regular. Fruit large, ovate-oblong; beak slight, sinus absent, peel thick, apricot yellow; flesh firm, fibreless. Fruit quality superb with excellent sugar acid blend., TSS (24-20° Brix), good keeping quality (15 days). It is suitable for table and canning purposes. Maturity during 3^rd – 4^th week of July.

After doing all hard work during fruit production the last operation is harvesting on field. Though it is last operation, it should be done very carefully to get the quality harvest. Harvesting of fruits mainly depends upon the nature of fruit. Here nature refers to the classes of fruits divided on the basis of their respiratory pattern and ethylene production. On the basis of the respiratory pattern the fruits can be divided in to two categories, first one is climacteric and the second one is non climacteric.

1. Climacteric fruits: The meaning of word „climacteric is a critical period or event. Here, climacteric refers to the event of respiratory rise before the ripening phase. Those fruits which show such patterns are known as climacteric fruits (Taiz and Zeiger, 2002) Examples: Mango, guava, apple, banana, sapota, papaya, peach, pear, plum, fig, Annona.
2. Non climacteric fruits: Non climacteric fruits do not exhibit the respiration and ethylene production rise (Taiz and Zeiger, 2002). Examples: Citrus, grapes, pineapple, pomegranate, litchi, ber, jamun, cashew, cherry, strawberry.

Fruit drop is a premature shedding of fruitsbefore harvesting for commercial purpose. There are so many reasons for fruit drop like internal (Hormonal balance, morphological and genetical) and external (biotic and abiotic) factors. Fruit drop is very much serious in some fruits like apple, peach, currant, mango, citrus etc. Fruit drop may occur at various stages of fruit growth,starting right from fruit setting till its harvesting. It may be natural, environmental or pest related.Losses due to fruit drop at various stages have long been a serious threat to the fruit growers. After determining the actual cause of fruit drop, adoption of a suitable control measure can bring relief to the growers. Among different drops, pre-harvest drop is of great economic importance which can cause serious crop loss to farmer.

Fruit is a structure which arises from an ovary or fusion of several ovaries after fertilization and may or may not carry associated floral parts. Fruit formation is an evolutionary mechanism designed to support and dispersal of seed by various agencies.With few exceptions e.g. banana, it is necessary for the flowers to be fertilized to set fruit. Fruit set succeeds the process which involves fusion of male and female gametes inside the ovary and is called fertilization. Fruit setting has long been remained a major problem as is evident from the old Greek literature and wall paintings where male panicles of date palm were being rubbed against the female flowers to get good fruit set.Lack of pollination with compatible source leads to the flowers drop except the flowers which set parthenocarpically. Further if fertilization is affected even then the flower drop and this decision depends upon the internal hormonal levels of the plant and prevailing climatic conditions.On the basis of pollination requirement fruit plants can be autogamous, allogamous or geitonogamous. In case of fruit plants like grape, peach where pollen produced by the same flower affect the fertilization are called autogamous and fruits like apple, kiwi, pistachio necessarily require pollen produced on some other plant or cultivar which are compatible can affect fertilization are called allogamous. Another condition exists where pollen grains from the same plant affect fertilization in flower at different part of the plant e.g. Walnut, pecan nut and is called geitonogamy. Similarly on the basis of compatibility between pollen and stigma, plants can be self unfruitfull, partially self fruitfull and self fruitfull.Self fruitfulness indicates that fruit species or cultivars produce abundant viable pollen grains whose shedding coincides with the receptivity of stigma, pollination is effective and there are no pre and post fertilization barriers. However, partial self fruitfulness and self un-fruitfulness exhibits number of causes. In case of fully self fruitfull types, a solid block of a single cultivar can be raised without making any provision for cross pollination, however it has been reported that provision of cross pollination in autoganmous crops increases the fruit-set. In case of self unfruitful and partially self unfruitful types, provision of cross pollination is necessary to get the fruits. Proper selection of the cultivars is therefore important from the point of fruit yield for which besides overlapping of blossoming season over long periods, the time of maturity, productiveness, market values etc. are of importance. Pollenizer must be a heavy pollen producer to ensure better chances of cross fertilization. Although pollenizers are desirable, their number must be restricted so that these do not become uneconomical because the pollenizer trees occupy space, consume nutrition and take away attention of the fruit grower without any return in yield, which would have otherwise been diverted to the trees capable of bearing fruits. Numerous environmental, edaphic, plant characters affect the fruit set and are discussed as under:

Introduction

Fruits play a vital role in improving human health which are called as protective foods rich in vitamins, minerals, fats, oils, proteins and improves in economy of producers, exporters and industrialists. Fruit crops can be classified into two broad categories i.e. ever green and deciduous trees.

1. Evergreen fruit trees grow under tropical and subtropical climate and they are not dependent on chilling requirement for floral bud differentiation and flowering. Ex: Mango, Citrus, Guava, Sapota, Papaya etc.,
2. Deciduous fruit trees require dormancy during winter season and chilling units for floral initiation and have specialized modifications to protect sensitive growing tissue from unfavourable conditions. Ex: Apple, Pear, Peach, Plum, Apricot, Cherry, Grapevine, Walnut, Almonds etc.,

Water is one of the most important and critical input for agricultural production system. The demand for food grains is increasing day by day due to increasing population. The irrigated agriculture provides the crop water productivity of about 2.5 tonnes per hectare and the overall irrigation efficiency is only about 30%, which is below the world average level. In the above scenario it is necessary to have the irrigation system in which both the crop water productivity and irrigation efficiency increases considerably. Micro irrigation has become the most viable and efficient technology in such a situation. It provides several advantages in the context of crop agronomy, water and energy conservation. Micro irrigation has the potential to achieve the crop water productivity to a desired level of 4 tonnes per hectare and simultaneously maintain the irrigation efficiency above 80%. The total coverage of micro irrigation in the tenth plan is only about 2 million hectare. The task force on micro irrigation (2004) has indicated a potential of 69 million hectare for our country. So there is a tremendous potential available and the coverage of micro irrigation has to be increased to cover more crop and more new areas.

In the words of Leonardo the vinci, “water is the driver of life”. It is said to be the liquid of life or elixir of life. Water availability is essential to consider as commercial orchards must have reliability of supply and cannot produce optimum yields without irrigation. Water management is one of the largest and most important inputs into an orchard. The single environmental component which determines the type of fruit plants to be selected for a specific ecological situation is the moisture status of the region. Different fruit plants preferring diverse moisture status have wide peculiarity in their anatomical and morphological structures as well as various modifications in their water absorbing organs. They are also seen to have varied capabilities to acquire and utilize water efficiently. In the plant system, the rate of dry matter production has a definite relation with the rate of transpirational loss of water and this transpiration ration is calculated on the basis of unit of water required to produce unit of drymatter. However, while calculating the water requirement of fruit plants, a number of factors, in addition to water use efficiency, are taken in to consideration. Naturally water requirement of a particular fruit plants varies with the agro-ecological condition of different places. Moreover the same cannot be equal in an established orchard and a newly planted one. In established orchard, the trees are grown in community where improved water use efficiency lower down the water requirement of the trees.

Growth is the fundamental property of all living organisms. It is an irreversible permanent increase in size, volume or mass of a cell or organ or whole organism accompanied by an increase in dry weight. Where, development is sum total of growth and differentiation. It is governed by both environmental and internal factors. The development of a plant is highly complex phenomena (Table 1).

In nature, plantspecies flowers produce fruits and seeds and the primary objective is to reproduce them. Plant species those are unable to produce viable seeds, reproduce themselves by other means. With a common of these processes they vary in various aspects of flowering and fruiting. The variations may be due to their different growing habits, requirement of different environments, differences in their basic nature etc. Here we are going to discuss different types of bearing habits do exists in fruit crops.

Growth Habit

Growth is quantitative irreversible increase in the existing size of say plant or a shoot or simply a leaf etc. Fruit crops can be classified on the basis of their growth habits in two major classes. One is evergreen and second is deciduous. Evergreens include those plants which bear their leaves throughout the year. Examples are mango, litchi, guava and orange. Whereas, deciduous trees shed their leaves during a part of year (when weather is adverse i.e. during winter). Mostly temperate fruits belong to this category. The presence or absence of leaves makes very big difference in their physiology, their bearing season and pattern etc. These two categories also make a basic group to study them separately with respect to many aspects viz. source and sink relationships, pruning etc.

The damage due to frost in fruit crops has been a problem for farmers since starting from their cultivation. Damage caused by frost is a worldwide problem because if all aspects of crop production are well managed, one night of freezing temperatures can lead to complete crop loss. According to Bagdonaset al. (1978) frost periods in temperate regions are shorter in duration and occur more frequently whereas in subtropical climates it is occurs with slow moving cold air masses. In tropical regions, there is usually no or very less freezing damage except at higher elevations. In subtropical fruits crops, damages occurs mainly during the winter, whereas in deciduous fruit and nut trees, it occur mainly in spring, but sometimes it occurs in autumn as well. The region prone to frost should adjust the date of planting of crop, microclimate, variety and other preventive measure. According to Attaway (1997) in South Carolina, northern Florida and Georgia, orange fruit were commonly grown before 1835, but losses due to frost damage, farmers did not prefer to grow oranges in that regions. The history of frost damage is more sporadic in nature leading to some major losses from time to time. In December 1990 and 1998

Californiacitrus industry suffered two major damaging events of frost which ranged from little damage in some regions to severe damage in the other region. The economic losses to fruit crops were high in the frost occurring in 1990 compare to frost in 1998.

Growing fruits can be fun, delightful experience and a challenging hobby. There are several good reasons to grow fruits. Fruits add beautiful colour and variety to your garden. Large amounts of fruit can be grown in a relatively small area.Store-bought fruits are often picked, shipped, and sold before they are fully ripened and generally stock selections that look prettiest but are not necessarily the best tasting. In addition, fresh garden fruits are a good source of vitamins; minerals, carbohydrates, fibre (Table 1) and will provide your family with flavorful, delicious and nutritious food. As an added bonus, the fruits you grow will taste much better than the fruits you find in the grocery store. Establishment of an orchard are a long term investment and require critical planning, selection of proper location and site, planting system and planting distance, varieties and the nursery plants to ensure maximum production.

Even if you have limited space, you can still enjoy growing fresh fruits in your garden by growing fruit plants in containers. You can grow any fruit tree in a container for a few years and then transplant it. You can also choose a dwarf variety, which is well suited to living in a container. If you carefully choose the kind and varieties of a fruit before you plant, you can harvest dessert-quality fruit from early summer through the fall. Many fruit plants are aesthetically pleasing and are good for “edible landscaping.” Some fruits, such as apple, citrus, blueberries and figs, make outstanding ornamental plants. Some people find a natural setting with plants placed throughout the landscape most aesthetically pleasing. But this makes maintenance more challenging.

Apple (Malus x domestica Borkh) is the most widely grown temperate fruit of the world considered as king of temperate fruit. It is one of the most delicious fruit rich in carbohydrates, minerals like calcium, phosphorus, iron, potassium, vitamin B6 and low in calories. Apples are extremely rich in important antioxidants, flavanoids, and dietary fiber. Apple is recommended to reduce the incidence of dental caries, and the phytonutrients and antioxidants may help reduce the risk of developing cancer, hypertension, diabetes and heart disease. Apple is chiefly used as table fruit. The various processed product like juices, jelly, preserve, canned slices, wine, concentrated juice, cider and powder are prepared from apple fruit.

Bael is one of the oldest and nutritional fruits of India (John and Stevenson, 1979). The tree is very hardy and thrives in almost all types of soil and climate. The ripe fruits of bael are rich in protein, fat, minerals, riboflavin, carotene, thiamine, niacin and vitamin C. The ripe fruit is lucrative while unripe fruit is prescribed for diarrhoea and dysentery (Mitra 1999, Roy, 1996, Singh and Ali, 1992, Singh, 2000). The marmelos in is most probably the therapeutically active principle of bael fruits.

18.1.1 Centre of diversity

The Bael tree has its origin from Eastern Ghats and central India. Its indigenous to Indian subcontinent and mainly found in tropical and subtropical regions. Even though it is native to India, it is found throughout Southeast Asia (Neeraj et al., 2017). The tree is also found as a wild tree, in lower ranges of Himalayas up to an elevation of 500 meters. Bael is also found growing along foothills of Himalayas, Uttaranchal, Jharkhand, Madhya Pradesh and the Deccan Plateau and along the east coast (Sharma et al., 2007).

Pineapple is one of the most important commercial fruits of the world. It is good source of vitamin A, B and fairly rich in vitamin C, minerals like calcium phosphorus and iron. Fresh fruit of pineapple is used as dissert fruit in the form of slices. Fruit is also used for juice, squash, jam, mixed jam and in canned form, fruit cone is used for preparing candy. Some cultivars of pineapple are used for extraction of fibre. The important states of pineapple growing are Assam, West Bengal, Tripura, Kerala, Andhra Pradesh, Bihar, Karnataka and Madhya Pradesh (Bal, 1997).

Cashewnut is an important delicious and dollar earning cash crop of India. This crop was remained neglected due to its poor yield potential and prolonged harvesting season. Cashew was introduced mostly for soil conservation purposes. In the beginning of the 20^th century cashew kernels gained importance in the international trade as edible nut and the crop began to be considered as having commercial value. Cashew is commercially grown for its kernels although cashewnut shell liquid (CNSL) and apples are also valuable by - products. It is considered to be the most important edible nut in the world trade (Ascenso, 1986). India is the largest producer and exporter of cashewnut in the world. Cashew kernel is the rich source of protein, carbohydrate, unsaturated fats and minerals like calcium, phosphorus and iron. Cashew proteins are complete with all essential amino acids. Fats of cashewnut are considered as complete, attractive, easily digestible and non fattening, it can be used by both olds and infants. The cashew apple juice is rich in vitamin C and it has some medicinal properties.

Coconut is a monocotyledonous woody plant belonging to the family Arecaceae or Palmae. It is presumed that the generic name Cocos and popular name coconut are derieved from Spanish word ‘Coco’ meaning “Monkey face” a probable reference to the three scars on the base of the shell resembling two eyes and a nose of monkey face. Coconut is valued most for its nut, the other components are coconut water, kernel, shell and husk. Coconut water is one of the most refreshing drinks which is also known for its medicinal value. It increases blood circulation in kidneys, causes profuse diuresis and eliminates mineral poisoning. It is a good substitute for saline glucose under gastroenteritis conditions. The coconut has been regarded as Kalpavriksha (tree of heaven) because all the parts of the palm is useful to mankind in one way or the other.

The dried kernels commonly called as copra is richest source of vegetable fat i.e. 60 to 67% oil. Coconut is major source of edible oil and it is propagated through seeds. India is largest producer of coir and its product. The coconut plant has about 4-6 years of juvenile phase with 60 years of productive life.

Litchi is a delicious fruit and generally consumed as a table fruit. It is one of the most popular fruits of India which is commonly taken as fresh or in dried forms. Litchi is also recognized as “Queen of the fruits”. Dried litchi commonly known as ‘Litchi nut’ is very popular among the Chinese living all over the world. This subtropical fruit cannot tolerate frost in winter and dry heat in summer. An interesting feature of the litchi plant is the symbiotic growth of Mycorrhiza fungi on roots of the tree. These fungi form nodules on the roots of litchi. The trees and the fungus live together to benefit each other. Litchi makes an excellent canned fruit and highly flavoured squash is prepared from inferior fruits. Besides, fruit, other parts of the plant like leaves, bark and roots are also used for various purposes. In China leaves are used for making poultices, bark and roots for making decoctions for throat gargle.

Date palm is one of the oldest fruits and was known to man many thousand years before Christ. It is staple food of the Arabs. Large quantities of date are imported by India from the Arabian countries. Wild date palm are seen growing even up to an altitude of 1500 M (Pareek, 1990), of course they do not fruit at this altitude every year. Raw sugar and a fermented drink ‘toddy’ are prepared from the sap of this palm. In the Indians valley, date palm is believed to have been introduced by the soldiers of Alexander the great in the fourth century B.C. and some wild groves of seedling date palm are found in the coastal belt in the Kachchh district of Gujarat. Investigations to develop indigenous production of dates in India were initiated during the 1950 by the ICAR at Regional Fruit Research Station, Abohar (Punjab). Some commercial varieties of date palm were introduced from USA, Pakistan and Middle East countries during 1955-1962. The extremely dry areas comprising Jaisalmer, Barmer, Bikaner and Jodhpur in Rajasthan, Abohar in Punjab and Kachchh in Gujarat are the potential regions for the date growing in India.

Pomegranate is an ancient and important fruit. It is grown for its delicious and juicy pink arils (outer growth of seed) which are eaten fresh (Keskar et al., 1993). Fresh fruit is of exquisite quality while its processed products like bottled juice, syrups and jelly are highly appreciated. The juice is considered useful for patients suffering from leprosy. Fruit juice easily fermented and may be used for the production of wine. Juice of wild pomegranate is used in the manufacture of citric acid and sodium citrate for medicinal purpose. Pomegranate is known best for curing the chronic stomach ailment. Seeds of pomegranate contain oil which has a potential for industrial use. Sour aril of the wild types can be utilized for the preparation of anardana.

Aonla has been regarded as a sacred tree in India. The tree is worshipped as mother earth and is believed to nurture humankind because the fruits are very nourishing. It is also known as Amrit phal. Aonla is mainly recognized due to its high nutritive, medicinal and therapeutic properties. It contains high amount of vitamin C (500-1500 mg/100 g), it is also rich in pectin, iron, calcium and phosphorous. Dried fruits of aonla can be is used in curing hemorrhage, diarrhea, chronic dysentery, diabetes, jaundice, dyspepsia, cough etc. Recently, aonla has gained more popularity in arid and semi-arid region of the country because of its hardy nature, prolific bearing capacity and ability to grow under various adversities as a remunerative crop (Shukla et al.2002). It may be an important fruit in future due to its high productivity, suitability in wasteland particularly salt affected soil and sandy soil of arid ecosystem. Aonla is the main ingredient of Chavanprash and Triphala powder which is used for curing different abnormalities. The fruit contains a chemical substance gallic acid and leucoanthocyanin which have antioxidant property.

Ber (chinese date, chinese fig or bore) is an important minor fruit of India. It is hardy fruit tree cultivated all over India and also known as poor man’s fruit. It is most widely cultivated in Punjab, Haryana, Rajasthan, Uttar Pardesh, Madhya Pradesh, Bihar, Gujarat, Maharashtra etc. Ber can do well even under marginal growing conditions and provides quality yields at low cost (Shukla, 1996). Fruits are mostly eaten fresh but the other forms, such as dried, candied, squash etc can also be prepared from ber. Stem bark, root and leaves have some medicinal values. Leaves of ber are used as fodder in dry regions. Ber tree (Ziziphus xylopyrus) is a host plant for rearing the Tachardia laccad a lac insect (Sharma and Kore, 1990).

Guava is also known as the “Apple of the Tropics”. It is very rich and cheap source of vitamin C and also contains a fair amount of calcium. Important guava growing states in the country are Uttar Pradesh, Bihar, Madhya Pradesh and Maharashtra. Allahabad district of Uttar Pradesh has the reputation of growing the best quality of guava fruits in the world (Mitra and Bose, 1990). The importance of guava is due to the fact that it is the hardy fruit which can be grown in alkaline and poorly drained soil.

Grapes are being grown commercially in the tropics. The region between the tropics of Cancer and Capricorn, which was once considered to be unsuitable for growing quality grapes (Winkler, 1962) is producing good quality grapes. Tropical countries, where grapes are grown are South–East Asia (India, Indonesia, Philippines, Thailand, Taiwan, South China and Australia), Central and South America (Brazil, Columbia, Ecuador, Mexico, Venezuela and West Indies) and Africa (Kenya, Nigeria and Zimbabwe). In India, about 90% of grapes are being produced in the tropical region of the peninsular states i.e. Maharashtra, Andhra Pradesh, Karnataka and Tamil Nadu. However, now-a-days grape is becoming popular in North India due to good income. The vines of tropical region grape are evergreen in nature and do not shed their leaves. In this condition, pruning is done twice in a year during April and September–October. But under North Indian conditions, grapes shed their leaves during winter and pruning is done in the month of February.

Citrus constitutes a major group of fruits comprising of mandarins, oranges, lemon, pummelo, grape fruits, tangelo, trifoliate orange, citron, citranges etc. Despite of inter-specific and inter-generic hybrids, Poncirus and Fortunella also belong to genus Citrus. During its long history, citrus has given the world numerous varieties both by open pollination, bud sports and of recently by controlled pollination and artificial induction of bud variation. Citrus fruit cultivation lies between latitude 40 0N also 40 0S where conditions are neither cold nor moist and dry. India is considered to be the home of several citrus species and they are found growing wild in some parts of the country. Many types of citrus still remain unexploited by man and such types are considered as semi wild. The productivity of citrus plant in our country is very low which is 7.65 tonnes/ha as acompared to Spain, Italy and Japan where it lies between 17-35 tonnes/ha. Sweet oranges cover an area of 42.4 thousand ha with an annual production of 510.8 thousand tonnes (Ghosh, 1985).

Papaya is an ideal fruit crop for growing in kitchen garden, backyards of home as well as orchards, especially those places nearer to cities or big town. It is also grown as a filler plant in orchard. The ripe fruits of papaya are consumed throughout the tropics and sub tropics. Fruits are also used in preparation of jam, soft drinks, ice cream flavour, crystalized fruits and syrups. Unripe fruits are commonly used as vegetables. Papain is prepared from the latex of immature fruits. It is proteolytic enzyme used for tendering of the meat, preparation of chewing gum and cosmetics etc. The ripe fresh fruit is rich source of vitamin-A (2500 I.U.), carbohydrates and minerals (Singh, 1969). Papaya on account of producing fruit in a short period after planting has attracted the attention of fruit growers to be cultivated on a large scale in the country. It is known as wholesome fruit which is valued for its nutritional and medicinal properties. Due to its nutritional, industrial and export demand, papaya is recognized the most potential fruit crop for its economic cultivation. The variable sex forms, propagational problems, susceptibility to frost and water logging, fungal and viral diseases are well identified problems in its cultivation. Economically the production life of papaya is 3 years and every time new plantation has to be raised. Papaya being transplanted at closer spacing is highly suitable for high density planting. Now high yielding variety with better fruit quality are needed to boost the production under varied agro edaphological situation.

Banana is one of the oldest fruits and second largest growing fruit crop in the world. It is also known as the Adam’s Fig and Apple of Paradise. Unlike other fruits banana is an herbaceous fruit plant. Banana breeding started in Trinidad, West Indies in 1922 and in Jamaica in 1924 (Shepherd, 1994). The driving force for this breeding programme was to develop improved Fusarium wilt (Fusarium oxysporum F. sp. Cubense) resistant banana for export trade (Buddenhagen, 1990). In 1960 both the programmes were combined under the Jamaica Banana Board. United Fruit Company also started a small breeding programme in Panama in 1920s. In India hybridization work was started at Central Banana Research Station, Aduthurai, Tamil Nadu in 1949. Important banana growing states are Maharashtra, Karnataka, Kerala, Tamil Nadu, Andhra Pradesh, Orissa, Bihar, West Bengal and Assam. Now a days in some districts of Uttar Pradesh, Harichal cultivar of banana is cultivated at commercial scale. In South India banana is extensively used in all auspicious occasions such as wedding, festival and worship. Banana is a good table fruit, besides, the cultivar Nendran is used for cooking, it is also used for preparation of halwa, sweet and chips etc. Main bud or heart of banana bunches is also used as vegetable in India, Thailand, Philippines, Malaysia and Indonesia. Musa textiles is known for strong fibre quality.

Mango is one of the choicest fruits of India, grown over an area of 1.23 million hectares in the country. Mango occupies the same position in India as occupied by the apple in temperate and grape in subtropical areas. In India mango is acclaimed as king of fruits. The name Mangifera was given for the first time by Bontius in 1658, when he referred to this plant as arbor Mangifera (The tree producing mango). Linnaeus also referred to it as Mangifera arbor in 1747, prior to changing the name to its present form (Mangifera indica) in 1753. Mango is good source of vitamin A and C apart from the usual content of minerals and other vitamins. Mango is also considered to have some medicinal properties. Ripe fruits of mango is fattening, diuretic and laxative. Smoke of burning is supposed to cure hiccups and some throat troubles and the kernal is effective against diarrhoea and asthma. Besides table purpose, fruits of mango can be used for the preparation of pickles, preserves, jam, amchur (mango powder), mango leather (ampapad) and mango fool (mango+milk+sugar)

Plant growth regulators are organic substances other than nutrient, which is required in minute quantity to modify the plant growth processes. PGR has very important role in fruit breeding which is used in every facet of crop improvement e.g. multiplication of hybrids/selection through asexual means or by micro propagation, breaking of seed dormancy, growth control, regulation of flowering, fruiting and induction of sterility in reproductive organs etc (Dhatt, 1985). Details of the various uses of plant growth regulators are given as under.

A plant is said to be healthy or normal when it carries out its physiological functions to the best of its genetic potential. These normal functions include division, differentiation, development, absorption of water and mineral from soil and translocation of these throughout the plants, photosynthesis and translocation of photosynthetic product to areas of utilization or storage, the metabolism of synthesized compounds, reproduction and storage of food supplies.

A plant becomes diseased when it is disturbed by pathogen under certain environmental conditions which interfere with one or more of its essential functions. Diseased plant refers to any disturbance brought about by living organism under environmental factors, which interfere with normal function of plant or in other words when any organ and part of plant is not doing their work properly and when either the growth or reproduction is not going forward in natural or regular manner.

India is bestowed with a wide range of agro-climatic and soil conditions. Therefore, almost all types of fruits can be grown in one or the other parts of the country. India is the second largest producer of fruits next to China. In India, fruit crops occupied 6.5 million hectares and it produces 96.75 million metric tonnes of fruits. India has exported fruits worth Rs. 4817.35 crores (692.01 USD Millions) (National Horticulture Board).

Improvement of fruit crops is difficult because of long gestation period, high heterozygosity, scanty information on inheritance pattern, often cross pollination, excessive fruit drop, parthenocarpy and less number of seeds restricting the availability of hybrid seedlings for evaluation. Even though, planned hybridization and clonal selections have been attempted in a number of fruit crops and these efforts have resulted in the development of promising varieties (mango, grape, guava, papaya, sapota, banana, etc). However, systematic and dedicated efforts are still required for the development of ideal varieties through modern tools in fruit crops.

In future, search for desired gene, critical study of inheritance pattern and use of biotechnological tools require due attention in combining ideal characteristics in varietal improvement programme of fruit crops.

Origin of weeds : Weeds originated together with crop plants. They have been there since the man started cultivating crops about 10,000 BC. Man during his stage of development, explored certain crop plant to suit his own taste and fancy and cultivated them as ‘crops’. The unexplored / unwanted / troublesome plants which are interfering with his activities are considered as weeds. About 30,000 plants species have been identified as definite weeds in the World. Which are infesting crop lands, water bodies, gardens, orchards, road sides, railway lines, irrigation channels etc.

Plants are differentiated into

a) Crops: Which meet the needs of human being.

b) Weeds: Which compete or interfere in human affairs.

Jethrotull is the first person to use the word weed.

Harvesting is the act of removing crop from where it was growing and moving it to a more secure location for processing and storage. Some root crops and fruits trees can be left in the field or orchard and harvested as needed, but most crops reach a period of maximum quality that is they ripen or mature and will deteriorate if left exposed to the elements. While the major factor determining the time of harvest is the maturity of the crops and other factors such as weather, availability of harvest equipments, packing, drying, transport and storage facilities.

Economic and marketing issues are often even more important to consider when to harvest commodity. Before harvesting of crop, grower must be sure about demand of the produce.

Harvesting the crop at optimum maturity is critical for reaping the benefits of season long efforts on crop production. After final decision on crop maturity, care must be taken to avoid losses during harvest, threshing, transport and storage. Processing is equally important to keep the produce in good condition for realizing good price.

Crop maturity: There are different types of maturity namely physiological maturity, harvest maturity and storage maturity.

Physiological maturity: It is the stage of development in the life cycle of plant when the plant reaches maximum dry weight. At this stage any further increase in inputs does not produce any gain in yield. There is cessation in growth and grain filling at this stage. Grain at this stage has 40 per cent moisture and 90 per cent produce is matured and this remaining 10 per cent still immature. So farmers should harvest at stage to get maximum benefit.

Problem soils are an important ecological entity of arid, semiarid or humid climate of our country. In India saline and sodic soils are serious threat to produce enough food grains for growing population. The other main problem is acid and acid sulphate soil, spread in one third of cultivated land.

Problem soils are either deficient in plant nutrients or the nutrient availability is inhibited by the antagonistic effect of the nutrient element present in excessive amounts as soluble or exchangeable ions.

Crop adaption is closely related to genetics and plant physiology. Knowledge of basic of biological evolution and genetics is essential for an understanding of crop adaptation. Natural selection, the fundamental basis of adaptation has been atmost importance in determining the characteristic of present day crops and its still of great significance in modern plant breeding.

Ecology and ecosystem: Ecology and ecosystem influences adaption and distribution of crops. As such basic knowledge of ecology and ecosystem is necessary to understand adaptation and distribution of crops for maximum economic yields through efficient use of natural and applied inputs.

Ecosystem ecology is the integrated study of living and non living components of ecosystems and their interactions within an ecosystem frame work. This science examines how ecosystems work and relates this to their components such as chemicals, bedrock, soil, plant and animals.

Ecology is the scientific study of relations that living organisms have with respect to each other and their natural environment. Under ecology we study various ecosystems which are part of the biosphere. An ecosystem includes all the organisms and the non living environment that are found in particular place.

Cropping systems are designed to mimic nature and bring diversity into our farming system. The cropping system should provide enough food for the family, fodder for cattle and generate sufficient cash income for domestic and cultivation expenses.

The objective of any cropping system is efficient utilization of all resources viz., land, water and solar radiation, maintaining stability in production and obtaining higher net returns. The efficiency is measured by the quantity of produce obtained per unit resource used in a given time. The objective of traditional agriculture was to increase the production by two means:

a) By increasing area under cultivation.

b) By increasing the productivity per unit area of the crop.