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Durian, an exotic fruit, native to Malayasia and Indonesia, is considered to be the ‘King of all fruits’ in South East Asia. The term ‘Durian’ has been derived from the Malay word ‘Duri’ which means thorn. The fruit has a tough, thick, thorny husk that resembles the husk of jackfruit. The notorious odor has given rise to the unflattering terms like “Civet Cat Tree”, and “Civet Fruit” in India and “Stinkvrucht” in Dutch. Durian is delicious, soft and succulent with a distinctive sulphuric smell. It is characterized by the rich, buttery smooth and luscious flesh. The fruit is distinctive for its large size, unique odour and formidable thorn-covered husk. The fruit is a good source of carbohydrates, protein, dietary fiber and energy. Some of the other durian fruit benefits are their high iron content and lack of cholestrol. It is rich in vitamin B, C and E, as well as in amino acids. The jelly is prepared from over ripe fruits which is sour in taste.

Phoenix dactylifera commonly known as the true date palm, is a palm in the genus Phoenix, cultivated for its edible sweet fruits. The fruit’s English name as well as the Latin species name dactylifera, both come from the Greek word for “finger,” Daktulos, because of the fruit’s elongated shape. The date palm is believed to have originated in the lands around the Persian Gulf. Date palms are said to thrive with their “feet in water and heads in the sun” because they need plenty of ground water but high heat and arid weather to produce fruit. Therefore, date palms grow best in hot and arid climates.

The custard apple is believed to be a native of the West Indies but it was carried in early times to southern Mexico through Central America. The custard apple, is generally rated as “ugly duckling” species among the prominent members of the genus Annona. It is sometimes erroneously termed “sugar apple” or “sweetsop”. The custard-apple is also called bullock’s heart or bull’s heart. The name “Custard Apple” is due to its custard like taste. The fruit has a peculiar aroma which makes a sweet drink and can be used as a milk substitute. Custard apple fruit with a sugary, grainy taste is rich in calories. The fruits are packed with vitamins (A, B and C) and minerals (iron, calcium, magnesium and potassium). The fruit flesh can be scooped from the skin and eaten as is or served with light cream and a sprinkling of sugar. Often it is pressed through a sieve and added to milk shakes, custards or ice cream.

Coconuts are the fruit of the coconut palm, botanically known as Cocos nucifera, where nucifera means “nut-bearing”. The fruit-bearing palms are native to Malaysia and southern Asia. The coconut has been regarded as ‘man’s most useful tree’, ‘mankind’s greatest provider in the tropics’, ‘one of the nature’s greatest gifts to man’, ‘tree of life’, ‘tree of abundance’, ‘tree of plenty’ and the ‘tree of heaven’ or ‘Kalpa Vriksha’ in India. In Sanskrit Kalpa Vriksha means “tree which gives all that is necessary for living” because nearly all parts of the tree can be used in some manner or another. The Indian state of Kerala is known as the land of coconuts. The name derives from “Kera” (the coconut tree) and “Alam” (place or earth). It has great antiquity in India which is also evident from the fact that the part of Malabar Coast, extending from South Kanara to Cape Comorin, is known as Keralam meaning the land of coconut. The coconut industry is intimately associated with the rural life and occupation of the people of Malabar Coast.

Citrus fruits are originated in the tropical and sub tropical regions of South East Asia, particularly in India and China. North East India is the native place of many citrus species. Citrus fruit has been cultivated in an ever-widening area since ancient times. Although oranges are the major fruit in the citrus fruits accounting for about 70 per cent of citrus output, the group also includes small citrus fruits (such as tangerines, mandarins, clementines and satsumas), lemons, limes and grapefruits. Citrus fruits are consumed as fresh fruit or utilized for preparing processed citrus products. Approximately one third of total citrus production is utilized for processing. India ranks sixth in the production of citrus fruits in the world. In India, it is primarily grown in Maharashtra, Andhra Pradesh, Punjab, Karnataka, Uttaranchal, Bihar, Orissa, Assam and Gujarat. Citrus fruits have several beneficial health and nutritive properties. They are rich in Vitamin C and folic acid, as well as a good source of fiber. In addition they contain potassium, calcium, folate, thiamine, niacin, vitamin B6, phosphorus, magnesium and copper.

Prunus avium means “Bird Cherry” in the Latin language, is commonly known as ‘Sweet cherry’. Cherries have pleased the palates of food lovers for centuries. Their ruby-red colour and tangy taste won the hearts of kings, queens and noblemen in the history, making a special place for cherries on their tables. The ultimate celebration of cherries is the National Cherry Festival. It is held every year in July in the “Cherry Capital of the World”-Traverse City, Michigan. This festival originated from a spring ceremony known as the “Blessing of the Blossoms.” Thousands of visitors come from all over the world to celebrate the harvest and of course, eat cherries. A delicious fruit, cherry is rich in protein and sugars. Cherry is an excellent source of minerals like potassium, manganese, magnesium, iron, phosphorous and copper. Good amounts of vitamins (A, B, C and K) are found in cherries. They also contain anthocyanins, melatonin and fibers. It has more calorific value than apple. 

The English name of cashewnut derives from the Portuguese name for the fruit of the cashew tree, Caju. It is native to the coastal areas of north-eastern Brazil. It was introduced in Goa by the Portuguese in the 16th century mainly to control soil erosion and to use in afforestation programmes but now it has become an important cash crop of Goa. The fruit of the cashew tree is an oval or pear-shaped accessory fruit known as ‘cashew apple’ sometimes called a pseudocarp or false fruit which develops from the receptacle of the cashew flower.  The cashew nut is a popular snack with a rich flavour that is often eaten on its own, lightly salted or sugared. Cashew nuts are also sold covered in chocolate. In Goa, the cashew apple is mashed and juice is extracted and kept for fermentation to prepare beverage called fenny. 

Carambola or starfruit is native to Indonesia. The fruit has ridges running down its sides (usually five) which in cross-section resembles a star, hence its also known as starfruit. It has a waxy, golden yellow to green coloured skin with a complicated flavour combination that includes plums, pineapples and lemons. Carambola consists of two main types of varieties viz.  sour and sweet. The sour types contain as much as 1 per cent acid and the sweet types have low acid (0.4 per cent) content with 5 per cent sugars.

The breadfruit is believed to be native to New Guinea. It is grown throughout the tropics. Breadfruit is a staple food in many tropical regions. Raw breadfruit has a very light fragrant taste that is somewhat like a guava, but not as sweet. The texture of raw breadfruit is rather tough and rubbery. It is used more as a vegetable than as a fruit. It can be eaten ripe as a fruit or under-ripe as a vegetable. Soft or overripe breadfruit is best for making chips and biscuits. The dried fruit can be made into flour. Its flour is much richer than wheat flour in lysine and other essential amino acids. Breadfruit is high in calories and contains a good amount of vitamin C and potassium with smaller amounts of calcium, iron and magnesium. The wood is yellowish or yellow grey with dark markings or orange speckles; light in weight; not very hard but strong, elastic and termite resistant and is used for construction and furniture. Fiber from the bark is highly durable and is used for clothing in Malaysia.

Ber is most commonly found in the tropical and sub-tropical regions of the world. Originally native to India, it is now widely naturalized in tropical region from Africa to Afghanistan, China, Malaysia, Australia and in some Pacific regions. The major production regions for Indian jujube are the arid and semi arid regions of India. It is also known as ‘King of Arid Fruits’ and ‘Poor Man’s Fruit’. In Philippines it is called manzana or manzanita (“apple” or “little apple”). Fully ripe fruits are less crisp and somewhat mealy; overripe fruits are wrinkled, the flesh buff-coloured, soft, spongy and musky. 

The word banana is derived from the Arabic word “banan,” which means finger and it is known as “the fruit of the wise”. In the middle ages, the banana was thought to be the “forbidden fruit of paradise”. Bananas are the most popular fruit in the world. Members of the genus Musa are considered to be derived from the wild species Musa acuminata (AA) and Musa balbisiana (BB). It is not a tree, but a perennial herb the leaves of which are usually grouped together, forming a trunk-like structure called pseudostem. The origin of bananas is believed to be Malaysia or India. Bananas are a very important commodity for developing countries, with a clear dual nature as they are at the same time a major staple commodity and a fundamental export commodity. There are almost 1000 varieties of bananas in the world with lot of commercially recommended cultivars. The most commonly known banana is the Cavendish variety, which is usually produced for export markets.

Bael is commonly known as Bengal quince, Indian quince, golden apple, holy fruit, stone apple and bel. It is more prized for its medicinal virtues than its edible quality.  The deciduous tree with trifoliate aromatic leaves is traditionally used as sacred offering to ‘Lord Shiva’. Fruit is a hard-shelled berry and very well-known for its medicinal properties due to marmelosin content. The ripe fruit is tonic, restorative, laxative and good for heart and brain. The pulp is often processed as nectar or squash. A popular drink called “Sherbet” in India is made by beating the seeded pulp together with milk and sugar. A beverage is also made by combining bael fruit pulp with that of tamarind. These drinks are consumed perhaps less as food or refreshment than for their medicinal effects. For medicinal use, the young fruits, while still tender, are commonly sliced horizontally and sun-dried and sold in local markets. The fruit, roots and leaves have antibiotic activity. The root, leaves and bark are used in treating snakebites.

Avocado is a pear-shaped berry, which is otherwise known as alligator pear or butter fruit. The term alligator pear is due to the scaly appearance of some varieties of avocado, especially, the Hass avocados, which possesses black leathery skin. The edible portion of avocado is its flesh, which is yellowish green in colour. This flesh has a slightly nutty flavour with the consistency of butter. Avocado contains vitamins A, C, and B complex that sustain accurate performance of neurotransmitter which makes it as a superior food for the nervous system. Avocados have the highest energy value (245 cal/100 g) of any fruit besides being a reservoir of several vitamins and minerals (calcium and magnesium) that can calm and aid restorative sleep which is essential for nervous system to perform efficiently. Avocado is mainly used fresh, in sandwich filling or in salads. It can also be used in ice creams and milk shakes and the pulp may be preserved by freezing. The end quality of avocado determines its nutritional value. 

Apricot is commonly known as Armenian plum. Its scientific name Prunus armeniaca derives from the assumption that apricot was known in Armenia during ancient times and has been cultivated there for so long that it is often thought to be native of that place. The cultivated apricot has its origin in North-Eastern China, whereas wild apricot, popularly known as ‘Zardalu’, appears to be indigenous to India. Generally, there are two types of apricot, namely, sweet kernel type and bitter kernel type.

Delicious and crunchy apple fruit is one of the most popular fruit favoured by health conscious, fitness freaks who believe in “health is wealth”. It is one of the popular wonderful fruit that contains a long list of essential nutrients that in the true sense are indispensable for human health. The antioxidants in apple have many health promoting and disease prevention properties; thus justifying the adage “An apple a day keeps the doctor away”. Apples help in controlling heart diseases, weight loss and cholesterol levels. Apples do not have any cholesterol instead they have fibre which reduces cholesterol by preventing reabsorption and thus are low in calories. Unpeeled apples provide plenty of nutrients which are present just under the skin. Apples are a good source of minerals like potassium, calcium, magnesium and iron, vitamins of B-complex such as riboflavin and pyridoxine (vitamin B6), vitamin C, folic acid and beta carotene. Apart from this they also contain appreciable quantities of tartaric acid that gives tart flavour to them.

Aonla, indigenous to Indian subcontinent popularly known as Indian gooseberry (Amla), is a fruit with immense nutritional and medicinal value. In fact, aonla, in its processed form is very popular among the social elites. Its fruit is valued very high amongst the indigenous medicinal fruits and has even been recommended by the ancient Ayurvedic system for sound health. Aonla is the second largest source of Vitamin C (600 mg/100 gm) among all the fruits, after Barbados cherry and this is 10 times the amount of Vitamin C present in orange. Vitamin C plays a major role in the health of the teeth and gums. In addition to this, it increases the resistance against pathogenic attacks. Aonla is also rich in fibers (3.4%) that are important for the smooth flow of ingested food in our alimentary canal. It also contains carbohydrates (14%) and vitamin B1 (30 mg/100g of fruit weight). Minerals like iron, calcium and magnesium, which are crucial for the various metabolic reactions in a human body, are also present in ample quantities in aonla. 

Physiological or abiotic disorders are mainly caused by changing environmental conditions such as temperature, moisture, unbalanced soil nutrients, inadequate or excess of certain soil minerals, extremes of soil pH and poor drainage. The distinction between physiological or abiotic disorders from other disorders is that they are not caused by living organisms (viruses, bacteria, fungi, insects, etc.), but they are the result of abiotic situations (inanimate) i.e. their agents are non-living in nature which causes deviation from normal growth. They results in physical or chemical changes in a plant which is far away from what is normal and is generally caused by an external factor. Non-infectious disorders in some cases are easy to identify, but others are difficult or even impossible to recognize. Most of them are non reversible once they have occurred. For the identification of physiological disorders it is important that one must know that:

Multiple Choice Questions

1.    The alkaloids percent in arecanut and betel vine is ……………………
2.    In India average productivity of plantation crops is ……………………..
3.    Largest producer country of rubber is…..............…………………….. 

       Crop                Highest producer state
    301.     Arecanut     (a) Assam
    302.     Cashew nut     (b) Kerala
    303.     Rubber     (c) Andhra Pradesh 
    304.     Tea     (d) Karnataka

1. Tea require months from plantation to reach plucking is:
    (a)    18-20     (b)    22-24     
    (c)    36-40     (d)    30-34
2. Fruit of coffee is:
    (a)    Pome     (b)    Drupe     
    (c)    Berry     (d)    Aggregate

Botanical Name : Piper betel
Family : Piperaceae
Origin : Malaysia.
Chromosome No. : 2n=2x=26 
Useable Part : Leaf 
    ·    Betelvine leaves have a strong pungent aromatic flovour and are widely used as masticatory. 

Botanical Name: Elaeis guineensis Jacq
Family: Arecaceae 
Chromosome No.: 2n= 2x=-32
Origin: Tropical Africa. 
Type of Fruit: Drupe
Type of Inflorescence: Spadix
Useable Part:-Fruit.

Botanical Name: Borassus fabellifier
    ·    Borassus flabellifer - Asian Palmyra palm/Lontar palm/Doub palm/Sea Coconut (Southern Asia and Southeast Asia)
    ·    Borassus aethiopum - African Palmyra Palm (Tropical Africa)
    ·    Borassus akeassii - Ake Assi’s Palmyra Palm (West Africa)
    ·    Borassus heineanus - New Guinea Palmyra Palm (New Guinea)
    ·    Borassus madagascariensis - Madagascar Palmyra Palm (Madagascar)
    ·    Borassus sambiranensis - Sambirano Palmyra Palm (Madagascar)

Two species mostly grown worldwide

Botanical Name: Hevea brasiliensis
Family: Euphorbiacace
Origin: Brazil
Chromosome No.: 36
Useful Part: Latex 
Cera Rubber: Manihot glaziovii
Para Rubber: Hevea brasiliensis
Indian Rubber: Ficus elastic
Panama Rubber: Castiolla elastic
Guayul Rubber: Parthenium argentatum

Chinese big leaf tea (Camellia sinensis var. macrophylla).
Chinese small leaf tea (Camellia sinensis var. bohea)
Shan tea (Camellia sinensis var. Shan)
Indo-China or Cambod tea (Camellia assamica subspecies lasiocalyx)
Indian tea (Camellia sinensis var. assamica)
Family:  Theaceae
Chromosome No.: 2n = 2x = 30
Origin: China (East and South Asia)
Useful Part: Bud and Leaves 

Botanical Name : Cocus nucifera Linn. 
Family : Palmae
Origin : South East Asia and Malaysia. 
Chromosome No :  2n = 32
Type of fruit : Drupe.
Type of Inflorescence : Spadix
Useable Part : Kernel

Botanical Name:  Theobroma cacao L. 
Family :   Sterculiaceae
Origin :  Central and South America.
Chromosome No :  2n=20
Type of fruit : Drupe.
Type of Inflorescence : Dichasial (cyme)
Useable Part : Seed 

Botanical Name : Anacardium occidentale L.
Family : Anacardiaceae 
Origin : North East Brazil in Latin America. 
Chromosome No. : 2n=2x=42
Type of fruit : Droup. 
Type of Inflorescence : Panicles (Both male and  hermaphrodite flowers occur on the same inflorescence)

Botanical Name: Areca catechu L.
Family : Palmae
Origin : India and South Eastern Countries.
Chromosome no. : 2n=32
Type of fruit : One-seeded berry.
Type of Inflorescence : Spadix 
Useable Part : Kernel or endosperm of the seed. 

The term plantation crops refers to those crops which are cultivated on an extensive scale in contiguous area, owned and managed by an individual or a company. The crops include tea, coffee, rubber, cocoa, coconut, arecanut, oil palm, palmyra and cashew. 
    ·    Coconut, cashew nut, cocoa, arecanut, oil palm and palmyra comes under Ministry of Agriculture.

To reduce the dependence on hazardous pesticides in modern agriculture, one of the most promising ways is to use insect-resistant cultivars. When available, planting resistant cultivars is one of our most effective, economically viable and environmentally sound tactics. The underlying concept of using host resistance to our advantage comes from the knowledge that most plants and animals are resistant to most potential insect attackers. Certain physiological, morphological, and/or behavioural characteristics inherited by organisms form a core of defense against species that would otherwise attack them (Pedigo, 2002).

Fresh vegetables are essential part of a healthy diet as it is an important source of vitamins, minerals and fibers. The nutritional content of vegetables varies considerably, though generally they contain little protein, fat and varying proportions of vitamins such as Vitamin A, Vitamin K and Vitamin B6, pro-vitamins, dietary minerals and carbohydrates (Woodruff, 1995; Whitaker, 2001). Vegetables contain multifarious other phytochemicals, some of which have been claimed to have antioxidant, antibacterial, antifungal, antiviral and anti-carcinogenic properties (Steinmetz and Potter, 1996; Gruda, 2005). A balanced diet should contain 250 - 325 g of vegetables and the average human requirement for vegetable is 285 g per person per day (Attavar, 2000). This perception of nutrition makes vegetables as a valued farm output.

Biological control is a strategy which employs utilization of natural enemies to reduce the damage caused by noxious organisms to tolerable levels (De Bach and Rosen, 1991). This is the most benign method for reducing pest population in vegetable ecosystem. It opens an amicable platform for production of organic vegetables with good export value. Since the late 1950s, much of the insect control in vegetables has been based on the use of synthetic chemical insecticides. Insecticides are relatively easy to use and have generally provided effective pest control. It is likely that they will always be a component of pest management programs. But, insecticides have some undesirable attributes. They usually present some degree of hazard to the applicator and other people who may come in contact with them, they can leave residues that some find unacceptable; they can contaminate soil and water and affect wildlife, aquatic life and other non-target organisms, they can interfere with beneficial organisms, such as pollinating insects and the natural enemies of pests. The insects also can develop resistance to insecticide. For these reasons, there is growing interest among farmers, entomologists and gardeners to explore and adopt methods that reduce pesticide use. 

Mites are small arthropods belonging to the subclass Acari (also known as Acarina) and the class Arachnida. The scientific discipline devoted to the study of ticks and mites is called acarology. In soil ecosystems, mites are favored by high organic matter content and by moist conditions, wherein they actively engage in the fragmentation and mixing of organic matter (Nyle and Ray, 2009). Mites are among the most diverse and successful of all the invertebrate groups. They have exploited an incredible array of habitats, and because of their small size (most are microscopic), go largely unnoticed. Many live freely in the soil or water, but there are also a large number of species that live as parasites on plants, animals, and some that feed on mold. It is estimated that 48,200 species of mites have been described (Halliday et al., 2000).

Vegetables are the largest important constituent of our daily diet as well as high value cash crops for small, marginal and large scale growers. These are rich in proteins, vitamins, minerals and dietary fibre which are essential for our normal body functions, prevention of malnutrition and deficiency diseases. Vegetables also play key role in neutralizing the acids produced during digestion of fatty foods and also provide valuable roughages which help in movement of food in intestine. Some of the vegetables are good sources of carbohydrates (leguminous vegetables, sweet potato, potato, onion, garlic and fenugreek) proteins (peas, beans, leafy vegetables and garlic) vitamin A (carrot, tomato, drumstick, leafy vegetables), Vitamin B (peas, garlic and tomato), vitamin C (green chillies, drumstick leaves, cole crops, leafy vegetables and leaves of radish) and minerals (leafy vegetables, drumstick pods etc.). As per dietician recommendation, our daily requirement is 75-125g of green leafy vegetables, 85g of other vegetables and 85 g of roots and tubers with other food (http://AgriInfo.in).

Endowed with varied agro-climatic situations, topography and soil type, India has been a leading vegetable producing country in the world occupying the second position in vegetable production after China with an annual production of 87.53 million tonnes from 5.86 million hectares having a share of 14.4 per cent to the world production. With commercial cultivation of as many as 61 annual and 4 perennial vegetables, India is the most diverse vegetable growing country in the world (Prakash et al., 2006). It is quite encouraging to know that our country occupies first position in cauliflower production and second in onion production. In India vegetables are grown both as mono-cropping (vegetable-vegetable cropping system) and sequential cropping after cereals, oil seeds and pulses. Besides, intercropping of vegetables with upland rice, maize, sugarcane, mango, papaya, banana and other fruit crops are also being encouraged in many areas. Vegetable based farming is rapidly emerging as one of the important  production systems in India  as this enterprise produces  a much higher income than any other type of farming in a shorter period of time. 

Protected cultivation practices can be defined as a cropping technique wherein the micro environment surrounding the plant body is controlled partially or fully as per plant need during their period of growth to maximize the yield and resource saving. Cultivation of vegetables under protective structures such as net houses has become popular in recent years (Kaur et al., 2004; Cheema et al., 2004; Singh et al., 2004). This enables, farmers to produce vegetables in the off-season, when fresh produce usually fetches higher price in the market.

Elephant foot yam, Amorphophallus campanutatus Blume (= Arum campanulatum Roxb.) belongs to the family Araceae. It is also known as elephant yam, Elephant bread, Suran, Sweet yam etc. It is a native to Tropical Asia and is found throughout the plains of the Indian sub-continent and some other parts of South East Asia and Africa growing both wild as well as cultivated. It is a robust herbaceous plant, with an erect solitary stem usually 1-2.5 m in height and bearing at the top one or two tripartite leaves, each part of which is deeply dissected into numerous segments. Towards the end of the plant’s cycle (usually 4-6 years) a large terminal inflorescence is produced, consisting of a short stalk and spathe and a spadix, which emits a malodorous smell, reminiscent of rotten meat.

Leafy vegetables are the herbs that are grown for their edible greens (leaves). Leafy vegetables are also called pot-herbs, greens, vegetable greens, and leafy greens are plant leaves eaten as a vegetable, sometimes accompanied by tender petioles and shoots. They come from a very wide variety of plants. As per Singh and Arora (1978), about 220 species belonging to the families, Amaranthaceae, Chenopodiaceae, Araceae, Asteraceae, Convolvulaceae, Malvaceae, Nymphalaceae, Papilionaceae etc. occur in India. Although most of them are grown wild, a few are regularly cultivated and consumed as cooked vegetables.

Coriander, Coriandrum sativum L. is an erect annual herb belongs to the family Apiaceae. Coriander may also be referred to as Cilantro, Chinese parsley or Dhania. In India it is cultivated in Rajasthan, Gujarat, Madhya Pradesh, Tamil Nadu, West Bengal, Uttar Praesh etc. The leaves of the plant are variable in shape, broadly lobed at the base of the plant. Leaves are slender and feathery higher on the flowering stems. It is a soft, hairless annual plant, surviving only one growing season. Except root all parts of the coriander plant are edible, but the fresh leaves and the dried seeds are most commonly used. It is also used as a condiment for its medicinal properties. Green leaves of coriander are extensively used for culinary purposes for a sweet aroma in cooking.

Curry leaf, Murraya koenigii (Linn.) is one of the most important plants exclusively known for its culinary and medicinal value. Leaves of the plant are widely used for flavouring food in Indian cookery. Leaves are also used in many Indian Ayurvedic and Unani prescriptions (Joseph and Peter, 1985). The whole plant including leaves, stems, flower, fruits and roots are used as tonic, stimulant, anti-flatulent, anti-diabetic, anti-oxidant (Khan et al., 1997) and anti-carcinogenic (Khanum et al., 2000). The plant is also used in curing digestive disorder, kidney disorder, burns and bruises, improving animal fertility, increasing shelf life of meat products, prevention of premature graying of hair and strengthening gums and teeths (Tara and Sharma, 2010). The plant is most widespread all over India and in some places it is grown wild. 

Moringa oleifera Linn. belongs to the family Moringaceae, that consists of only one genus with about 13 species of deciduous trees (Keay, 1989). It is believed to be the native of India-Pakistan-Nepal borders, but now is becoming widely distributed and grown in several countries, particularly in tropical and subtropical regions (Satti et al., 2013). Besides some other species, M. oleifera is recently being the most widely cultivated in numerous countries in Asia, including the Arabian Peninsula, central and south America and in most African countries like Benin, Burkina Faso, Cameron, Senegal, Mauritania, Niger, Nigeria, Tanzania, Uganda, Kenya and Sudan (Nasir and Ali, 1972; Ramachandran et al., 1980 and Parrotta, 2001).

Sweet potato, Ipomoea batatas (Linn.) originated in northwestern South America around 8000 - 6000 BC. The plant is a dicotyledonous, herbaceous, trailing vine which is the only economically important member of the family Convolvulaceae. The plant is generally characterised by starchy, succulent and tuberous storage roots; alternating palmately lobed leaves and medium sized sympetalous flowers which grow individually and vary in colour from white to varying degrees of purple (Austin et al., 1991). It is a perennial plant but is grown as an annual by vegetative propagation usually through vine cuttings and sometimes using either storage roots. Its growth habit is predominantly prostrate with a vine system that rapidly expands horizontally on the ground. The types of growth habit of sweet potatoes are erect, semi-erect, spreading and very spreading.

In countries like India where majority of the population are vegetarians, leguminous vegetables serve as the major source of protein in the diet. In the developing third world countries, especially for the poor, the major protein source in the diet are vegetable legumes. Most leguminous vegetables are rich in phosphorus, calcium, iron and a number of essential vitamins. Crops like soybean, groundnut and Bamabara groundnut are also rich in fats which are needed by the body to absorb vitamin A.

The green pepper or chilli is reported to be the native of tropical America (Thompson and Kelly, 1957). This was widely cultivated in Central and South America in early times and was unknown in Europe prior to the discovery of America. The chilli belongs to the family Solanaceae and genus Capsicum. Only four species are under cultivation, out of which the cultivation of the two, Capsicum pendulum and Capsicum pubescens, are restricted to South and Central America. The other two, Capsicum annuum and Capsicum fruitescens are commercially cultivated throughout the world. Capsicum annuum is the most commonly cultivated species and all green chillies in the market and most dry chillies belong to this group. Most of the small and highly pungent chillies belong to Capsicum fruitescens.

Members of the family Cruciferae commonly used as vegetable include Cabbage, Cauliflower, Broccoli, Brussels sprouts and mustard etc. The genus Brassica is known for its important agricultural and horticultural crops. A dislike for cabbage or broccoli can result from the fact that these plants contain a compound similar to phenylthiocarbamide (PTC), which is bitter or tasteless to some people depending on their ‘taste buds’ (Theresa, 1995). Almost all parts of some species or other have been developed for food, including the root (turnips), stems (kohlrabi), leaves (cabbage), flowers (cauliflower, broccoli), buds (Brussels sprouts, cabbage), and seeds (many, including mustard seed, and oil-producing rapeseed). Some forms with white or purple foliage or flowerheads are also sometimes grown for ornamental purpose.

Tomato, Lycopersicon esculentum Mill. is an important vegetable cultivated throughout the world; both outdoors and under protected structures for fresh market consumption and processing. In India this nutritive rich vegetable is grown over an area of 0.60 m ha with an estimated production of 11.9 mt. Productivity of tomato in India is lower (18.6 t/ha) than the world productivity (27 t/ha) (Anonymous 2009). Tomato is grown in a wide range of climatic conditions across states of Andhra Pradesh, Orissa, Karnataka, Maharashtra, West Bengal, Bihar, Gujarat, Uttar Pradesh and Chhattisgarh. Tomato crop is highly sensitive to environmental stress caused by high temperature and low soil moisture. In fact, temperature is rising in the tomato growing locations and can cause reduced fruit set and lower the quality of fruits.

Okra (Abelmoschus esculentus Moench), otherwise known as Lady’s finger or Bhindi is an annual malvaceous plant and the sixth important vegetable crop cultivated throughout the country mostly in kharif and summer seasons. Though it is reported to be originated from tropical and sub-tropical Africa, but it has gained much importance in India as the secondary centre of origin. India ranked first in okra production in the World and major okra producing Indian states are Uttar Pradesh, Bihar, Orissa, West Bengal, Andhra Pradesh, Karnataka and Assam (Anonymous, 2011).