eChapters

Cocoa (Theobroma cacao L.) is the third important beverage crop grown for its seeds known as beans, used mainly in chocolate industry. It is the source of cocoa butter and cocoa mass.

Coconut is the most beautiful and useful of palms known to mankind. Coconut is unique, producing a host of products and by products with distinctive applications at home and in industry. It is essentially an oil seed crop providing all amenities for human life, which include food, energetic beverage, medicine, fibre, wood, shell and a variety of raw materials for production of array of products of commercial importance. In view of its versatile uses and affinity to Indian culture, it is rightly called the “tree of heaven” or “Kalpavriksha”.

Coffee (Coffea species) occupies a pride of place, in the international trade of commodities, next to petroleum in trade volume and money value. Coffee is also the second important popular beverage for its aroma and mild stimulant action. Its dried beans are roasted, ground and brewed to make a stimulating & refreshing beverage. Its production forms the backbone of more than 60 developing nations. Use of coffee has evolved from original chewing of leaves and beans of the plant to relieve pain, hunger and fatigue to the present more sophisticated uses, like espresso and decaffeinated coffees. Its use was first discovered in Arabia around mid-15th century.

The oil palm (Elaeis guineensis Jacq.) is recognised as the cheapest edible oil-yielding crop and has become one of the major oil crops in the world. The most productive oil-bearing crop, oil palm yields about three times the oil yield of coconut, seven times that of rapeseed, and ten times that of soybean. In terms of world production, palm oil maintains second place after soybean as a source of vegetable oil and has overtaken other crops such as rapeseed, sunflower, groundnut, and cottonseed. Under good agricultural management, a hectare of oil palm yields 5 to 7 tonnes of oil / year (Henson, 1991). The crop is unique in producing 2 distinct types of oil- palm oil and palm kernel oil- used for culinary and industrial purposes. Being rich in b-carotene, palm oil contributes substantially to nutritional and energy requirements of masses.

Palmyra (Borassus flabellifer L.) is a tropical dioecious palm adapted to arid zone tracts. Though it is a versatile plant which yields many edible and non-edible products it is a less exploited species. It is used for sap, fruit, seed, leaf and fiber and timber products. From nutritional point of view, fruit pulp and seed shoot flour are the most important.Successful promotion of these as foods for general consumption depends on subjecting the fruit pulp to a debittering process, and the seed shoot flour, to initial detoxification processes (Thabrew and Jansz, 2004). Palmyra palms are the most numerous palms in the world after coconut palm (Fox, 1977). Despite this, they are the least studied of all the palms.

Natural rubber, cis-l,4 polyisoprene, produced in the milky cytoplasm (latex) of specialized cells called laticifers in certain plants is one of most important biological macromolecules, which is used as an industrial raw material for the manufacture of a variety of products. Natural rubber is found in the latex of over 2000 species of plants belonging to 311 genera under 79 families. However, Hevea brasiliensis, also known as Para rubber tree after the Brazilian port of Para, is the only commercial source of natural rubber mainly because of its abundance in latex, quality and convenience of harvesting. Hevea was first used as a source of rubber by the French.

Tea is the most important non-alcoholic beverage worldwide gaining further popularity as an important ‘health drink’. It is consumed as a morning drink by 2/3^rd of world population. Tea was used initially as a medicine and subsequently as beverage and now has proven to be a potential raw material for pharmaceutical industry. Tea is mainly consumed in the form of ‘fermented tea’ or ‘black tea’, ‘non-fermented’ or ‘green tea’ and semi-fermented or ‘oolong tea’ are also popular in Japan and China. Green leaves are also used as vegetables such as ‘leppet tea’ in Burma and ‘meing tea’ in Thailand.

1.1 Spice – definition and uses

Spice is defined as “a strongly flavoured or aromatic substance of vegetable origin, obtained from tropical plants, commonly used as a condiment”. A spice is a dried seed, fruit, root, rhizome, bark or vegetative substance or flower bud used in nutritionally insignificant quantities as a food additive for the purpose of flavoring. Spices are distinguished from herbs, which are leafy, green plant parts used for flavoring purposes. Herbs, such as basil or oregano, may be used fresh, and are commonly chopped into smaller pieces; spices, however, are dried and usually ground into a powder (http://www.reference.com/browse/wiki/Spice). American Spice Trade Association (ASTA) defines spices as “any dried plant product used primarily for seasoning purposes”. Included are tropical aromatics (pepper, cinnamon, cloves, etc.), leafy herbs (basil, oregano, marjoram, etc.), spice seeds (sesame, poppy, mustard, etc.) and dehydrated vegetables (onions, garlic, etc.) (http://www.astaspice.org/spice/frame_spice.htm). Many spices have other uses like food preservation, medicine, religious rituals, cosmetics, and perfumery or as vegetables.

1.0 INTRODUCTION

Soil fertility can be considered to be a measure of the soil’s ability to sustain satisfactory crop growth, both in the short and longer-term. Organic farming recognizes the soil as being central to a sustainable farming system. It could be argued that organically managed soils require a higher level of baseline fertility because shortfalls cannot be made up by applications of soluble fertilizers. Soil fertility is determined by a set of interactions between the physical and chemical environments of the system and by biological activity. Organic matter is linked intrinsically to soil fertility, because it is important in maintaining good soil physical conditions (e.g. soil structure, aeration and water holding capacity) and is an important nutrient reserve. Organic matter contains most of the soil reserve of N and large proportions of other nutrients such as phosphorus and sulphur.

1.0. INTRODUCTION

The plant nutrient cycling depends on micro organisms that constitute major components of the biosphere. Although less than one per cent is cultured, a tremendous diversity exists in their populations. Transformation of nutrients from soil to plants is brought about by soil microorganisms. Latest molecular techniques enable scientists to understand and appreciate the diversity and help to utilize the beneficial effects of microbial diversity for increased productivity. Among soil organisms intense activity is found in and around rhizosphere of plants because of the presence of the secreted nutrients such as carbohydrates, amino acids and other cellular components present at the growing tip of roots. These root colonizing micro organism form symbiotic, associative, or parasitic relationship with the plants. These organisms have evolved mechanisms to occupy and reside in the specialized niche. These mechanisms are often utilized both for growth enhancement and disease suppression. The host also plays an important role in selecting its own microflora for the rhizosphere similar to the probiotic microflora of human gastrointestinal tract (Haas and Keel 2003).

1.0 INTRODUCTION

Infestation by insect pests is a major factor responsible for the low productivity of spice crops in India. Spice crops such as black pepper (Piper nigrum L.), cardamom (Elettaria cardamomum Maton), ginger (Zingiber officinale Roscoe) and turmeric (Curcuma longa L.) are infested by many species of insect pests, some of which cause severe crop losses. Adoption of integrated pest management (IPM) schedules in which biological control forms a major component is more relevant in these crops since excessive use of insecticides could lead to pesticide residues in the produce and other ecological hazards. Spices are high-value and export-oriented in nature and pesticide residues are the most important non-tariff barriers on trade in these produces. There has been a renewed interest during the past decade in developing environment–friendly crop management schedules in sustainable agriculture including spice crops, reflecting the increasing concern over pesticide misuse.

1.0 INTRODUCTION

“Biological control is the reduction of the amount of inoculum or disease producing activity of a pathogen  or parasite  in its active or dormant state, by one or more organisms, accomplished naturally or through manipulation of the environment, host or antagonist or by mass introduction of one or more antagonists ” (Baker & Cook 1974). The biological world is a vast interacting network of living organisms in a state of dynamic equilibrium, reflecting changes in their physical environment and their relations to each other. Organisms exhibit many type of interactions in the process of achieving biological balance.  An organism may exert no effect on another or it may stimulate or inhibit the growth or development of the associate, it may stimulate or inhibit the formation of resting spores of the associate or it may enforce dormancy or cause lysis of the associate (Cooke & Baker, 1983).

1.0 INTRODUCTION

The bacteria in the genus Ralstonia, Xanthomonas, Agrobacterium, Xylella, Pantoea, Leifsonia, Curtobacterium, Enterobactor, Pseudomonas, Corynebacterium, Erwinia cause the most important bacterial diseases of crop plants. Few of them are directly responsible for post harvests losses during storage or transit and many of them are known to cause disease in the field. These diseases are economically important due their potential to cause crop failure in crops including spice crops. Among the bacteria genus Ralstonia is very important owing to its broad host range across the plant kingdom. Traditionally bacterial diseases of crops are prevented by the principle of ‘Disease Avoidance’ rather than disease control in the field. Their fast rate of multiplication, selective host and rapid spread in the field makes the disease control one of the challenges in the production system. The organic strategies are very well fit in the disease avoidance in the field. The preemptive strategies works exceedingly well for management of bacterial disease in any crop. Few genus such as Ralstonia, Enterobacter and Xanthomonas have been frequented in spice crops.

1.0 INTRODUCTION

Plant parasitic nematodes are among the major soil-borne crop pests that cause significant economic losses to a wide variety of crops. They cause an estimated annual crop-yield loss of US$78 billion worldwide which warrants for effective control strategies (Sasser and Freckman, 1987). Nematodes have the greatest impact on crop productivity when they attack the roots of seedlings or young plantlets (Ploeg, 2001). Nematode feeding also creates open wounds that provide entry to a wide variety of plant-pathogenic fungi and bacteria. These microbial infections are often more economically damaging than the direct effects of nematode feeding.

1.0 INTRODUCTION

Black pepper popularly known as ‘King of spices’ or ‘Black gold’ is one of the important and earliest known spices produced and exported from India. Its original home is the dense evergreen forests of Western Ghats in south India. The flavour and fragrance of this oriental spice had a magic spell in human civilization and culture since very ancient days. Expeditions in search of pepper led to the discovery of new trade routes.

1.0 INTRODUCTION

Cardamom (Elettaria cardamomum Maton.) acclaimed as the ‘Queen of Spices’ is the true cardamom belonging to the family Zingiberaceae. The cardamom of commerce is the dried ripe fruit and is one of the most important valued spices next only to saffron. It is native of evergreen forests of Western Ghats of South India. Cardamom is a shade loving plant (Pseophyte) thriving well in elevations up to 600-1200 m above MSL under an average annual rainfall of 1500-4000 mm and temperature range of 10-350C. India has been the world’s largest producer of cardamom until 1979-80. Later, Guatemala emerged as world’s premier producer and the exporter of cardamom accounting for about 90 per cent of the global trade. Cardamom is also grown lesser extent in Sri Lanka, Papua New Guinea and Tanzania.

1. INTRODUCTION

Ginger (Zingiber officinale Rosc.) is a perennial herb and the economic part is underground stem (rhizome), which is used as a spice. It is native to tropical South-East Asia, introduced into the West Indies, African countries and other tropical belt of the world. The ginger rhizome is harvested between 6 and 12 months after planting and used as spice in the fresh condition,  peeled and split dried or powedered forms. Ginger is utilized widely as a spice, for pickles, candies and as a medicinal herb. The anti-inflammatory and anti-nausea qualities of ginger have applications in the pharmaceutical industry. Ginger and supplements derived from ginger have received attention for the treatment of chronic inflammation. Administration of ginger has resulted in decreased symptoms of rheumatoid arthritis (Srivastava and Mustafa, 1992) and gingerol (a component of ginger) has been reported to have anti-inflammatory actions (Kiuchi et al., 1992; Tjendraputra et al., 2001).

1.0 INTRODUCTION

Turmeric (Curcuma domestica Val. (syn. C. longa Koenig non L.) is an important spice, a native of India and South East Asia. Chikarmane et al. (2003) by analyzing historical patterns of movement of South Asian and Southeast Asian people known to have used turmeric suggested that turmeric was introduced into Southeast Asia via Indian colonization in the early Christian centuries. An increase in colonization events from South India during this time was because of discoveries in navigational science and desires to expand civilizations, rather than military conquests. The cultural expansion from South India supports the introduction of turmeric cultivation to Southeast Asia via human means. These human migratory patterns are compared to a phylogenetic analysis of DNA sequence data within Curcuma, and suggested that key locations such as the Isthmus of Kra were important not only to human movement but to species evolution in Curcuma (Chikarmane et al., 2003).

1.0 INTRODUCTION

Vanilla is one of the most popular and widely used flavour materials in the world and it is the most expensive spice traded in the global market after Saffron (Crocus sativus L). The major consumers of vanilla beans currently are the developed countries with the US, France and Germany absorbing about 80 per cent of the world imports. Among them, the US imports 50-60 per cent while the latter 10-15 per cent each. They are also main re-exporters of both vanilla beans and processed products. The total area under vanilla cultivation in the world during 2002 was 38,066 ha with the production of around 4956 metric tones and increased to 76,440 ha with a production of 10, 360 tons during 2005 (FAO, 2007). The major vanilla producing countries are Madagascar, Comoros, Indonesia, Mexico and Reunion (Table 1). Area under vanilla in India during 2002-03 was 2545 ha with the production of 92 tonnes. (Spices Board, 2003) and increased to 5370 ha with a production of 196 tonnes during 2004-05.

1.0 INTRODUCTION

Among tree spices, nutmeg (Myristica fragrans Houtt) belonging to the family Myristicaceae is the most important, providing two spices, i.e. the nutmeg (dried seed) and the mace (dried aril covering the seed). The latter is more important. Nutmeg is cultivated mostly in the tropical areas of Indonesia and West Indies. The world annual production of nutmeg and mace is around 12000 tonnes and 2000 tonnes, respectively (Krishnamoorthy and Rema, 2001). A native of the Moluccas (The Banda Islands of East Indonesia), nutmeg is presently cultivated in several countries such as Grenada, Malaysia, Papua New Guinea, Sri Lanka, Fiji, some Caribbean Islands, Africa and China including India. Of late, Brazil also started its cultivation. The Indonesian nutmeg known as East Indian nutmeg shares 75% and Grenadian known as West Indian nutmeg shares 25% of world market and they are major suppliers in the world. The East Indian nutmeg is highly aromatic which is preferred by the USA. West Indian type is of mild flavour and is preferred in Europe. The major importers are USA, Canada, Japan and European countries. In USA, the oil is generally preferred whereas the Europeans consume it as whole spice.

1.0 INTRODUCTION

Capsicum or chilli including paprika belonging to family Solanaceae, is a native of new world tropics and sub tropics. Within the genus Capsicum, mainly five species have been recognized as domesticated namely, Capsicum annuum, C. baccatum, C. chinense, C. frutescens and C. pubescens. Most of the commercially cultivated chilli cultivars as well as paprika belong to the species C. annuum. The cultivated Capsicum was introduced to India and Southeastern Asia in the 17th century by the Portugese. The name Capsicum is possibly derived from the Greek word ‘Kapso’ meaning ‘to bite’ referring to the dominant pungency stimulated by the spice, while ‘Paprika’ means plants of the genus Capsicum, in the Hungarian language. ‘Paprika’, is defined in the world market as non-pungent (sweet) brilliant red ground Capsicum powder, derived from the thick flesh dried red pods, with most of the seeds and veins removed. Both chilli and paprika are widely consumed as vegetable and spice all over the world. Mostly, the cultivars grown in Asian countries are pungent, while less and non-pungent cultivars are more common in European countries. Chilli of commerce is the dried pod, while it was pericarp (outer skin of the dried fruit) for paprika.

1.0 INTRODUCTION
 
Coriander is a native of southern Europe and Asia Minor. In a treatise, Farrell (1999) has described coriander as indigenous to the Near East and Mediterranean region of North Africa and Southern Europe. According to early Sanskrit writings, coriander was known as far back as 5000 BC for its cultivation in India. Persia grew coriander 3000 years ago for adding fragrance to hanging garden of Babylon and seeds were found in Egyptian tombs of 960 BC. It has been used as an ingredient to traditional and folk medicine in the Middle East and Asia for more than 2000 years. There is archaeological evidence of coriander cultivation from Early Bronze Age in Macedonia (Fragiska, 2005)

1.0 INTRODUCTION

Fenugreek is one of the oldest cultivated spice crops of the world and grown for its medicinal value and forage in India, Western Asia and Nile valley since remote antiquity. In Egypt, it has been cultivated since 1000 BC and is part of the Indian diet for over 3000 years. Fenugreek is used as an important component of holy smoke in Egyptian incense. It is found growing wild in parts of northern India and cultivated all over the subcontinent for its green leaves and seeds. Fenugreek is a native of south-eastern Europe and Western Asia.  India is also said to be a native of fenugreek (Shanmugavelu et al., 2002) and found growing wild in Kashmir, Punjab and upper Gangetic plains.

1.0 INTRODUCTION

The fennel (Foeniculum vulgare Mill.) is important seed spices belonging to family Apiaceae, and a native of Southern Europe and Mediterranean area. Later it spread to the far East and far north in Europe. To the ancient Greeks, fennel represented success and so it was called “Marathon” in reference to the battle, fought in fennel field where the Greeks defeated the Persians in 490 B.C. Fennel was also a symbol of success to the Romans. During the thirteenth century in England, fennel was considered as a royal spice and was served to kings with fruits, bread and pickled fish seasoned with fennel seeds. Fennel was even described by Longfellow in his poem The Goblet of Life. According to early Sanskrit writings, fennel has been described as Madhurika and was known as far back as 2000 BC for its cultivation in India.

1.0 INTRODUCTION

The cumin (Cuminum cyminum Linn.) belonging to family Apiaceace is an important seed spice believed to be indigenous to northern Egypt, East Mediterranean region, Iran, Turkey  and India (Amin, 2003; Raghavan, 2007). It is popularly known as safed jeera and is one of the most common spices of daily use in the Indian sub-continent. Cumin is well known to ancient civilization. It is one of the oldest spices known since biblical times, valued mostly for their digestive properties and for flaovouring bread and other dishes during the periods of ceremonial fasting. As early as 5000 BC, Egyptians preserved the bodies of their kings by mummifying them with cumin, anise and marjoram.

1.0 INTRODUCTION

The crop production is as old as human civilization, it is an art, science and business. In the world of ‘Fast Food,’ food safety is a watch word. To accomplish safety food to consumers and fair price to producers through appropriate market channels, the concept of Good Agricultural Practices (GAP) has evolved in recent years. The stakeholders include governments, food processing and retailing industries, farmers, and consumers, who seek to meet specific objectives of food security, food quality, production efficiency, livelihoods and environmental benefits in both the medium and long term. GAP offers a means to help reach those objectives.

1.0 INTRODUCTION

The most significant factors distinguishing organic farming from eco-farming are the existence of production standards and certification procedures. Certification of organic farming is the procedure by which a written assurance is given by the certification agency that a clearly identified production or processing system has been methodically assessed and conforms to the specified requirements. It is a process certification rather than a product certification. Certification and labelling is usually done by an independent body to provide a guarantee that the production standards are met.  In case of organic products, certification is an acknowledgement that the products are produced according to organic production standards of certification bodies or associations or of the country. Organic production system is a land use system in accordance with set standards to the location specific conditions by integrating practices that foster cycling of resources, promoting ecological balance and conserve biodiversity. The prime principles of organic farming are,

Taxonomy is the science of identifying (discovering), describing, naming and classifying organisms. It is a complex summing up of knowledge starting with thorough analysis to base the synthesis that will end up in the name of a taxon. Correct identification of biological taxa is a necessary prerequisite to all other enquiries about the biological world. Taxonomists attempt to divide the world of living things (biodiversity) into distinguishable entities (taxa-such as species, genera, and families), develop tools (e.g., identification keys) to allow others to recognize and identify these taxa, and organize the described taxa within a hierarchical classification system that reflects evolutionary relationships. The outcomes of taxonomy are, therefore, very practical in terms of providing tools to facilitate identification, an infrastructure for organizing biological information, and a universal language for communicating information about the identity and classification of biological entities. Thus, naming and ordering of objects into groups is probably the most fundamental step in the development of scientific principles. Taxonomy identifies and enumerates the components of biological diversity providing basic knowledge underpinning pest management (Ramaraju and Pratheep, 2008). 

Brinjal (Solanum melongena Linn.) is one of the widely used vegetable crops and is popular in many countries viz. Central, South and South-East Asia, some part of Africa and Central America (Gurubban, 1977). It is also known as the aubergine, eggplant, melongene, guinea squash etc. Various data indicate that from the several species that evolved in Africa, one (Solanum incanum), gave rise to a distinct species which spread to South-East Asia as the wild ancestor of Solanum melongena (Lester, 1998). It was domesticated in India from the species Solanum incanum and India or Indo-China region is recognized as the centre of the eggplant diversity (Vavilov, 1951). Solanum melongena is a delicate, tropical perennial often cultivated as an annual in temperate climates. The fruit is botanically classified as a berry and contains numerous small, soft seeds which are edible, but have a bitter taste because they contain nicotinoid alkaloids. This is unsurprising as it is a close relative of tobacco.

‘Cucurbits’ is a term coined by Liberty Hyde Bailey for cultivated species of the family Cucurbitacae (Robinson and Decker-Walters, 2004). Presently, the term has been used not only for cultivated forms, but also for any species of the family Cucurbitacae. Among vegetables, the cucurbits form one of the largest groups with their wide adaptation from arid climates to the humid tropics. The family consists of about 118 genera and 825 species. In Asia, about 23 edible major and minor cucurbits are grown as vegetable. They are grown in summer and rainy seasons in India and even in winter in some parts of southern and western India as both annual and perennial crops. 

Potato is one of the major non cereal food crops in the world and ranks fourth after rice, wheat and maize. Due to its high production potential per unit area and time, the crop has been recorded for sustaining millions of lives during the times of war and hunger. Native of South America, this crop was introduced into India in early seventieth century. Currently India ranks 3rd for area and 2nd for production in the world [AICRP (Potato) Bulletin No. 2]. Potato is generally grown as rabi crop during October to December in gangetic plains of India but in hills it is grown almost throughout the year as commercial cultivation. In some states like Karnataka, it is generally grown during kharif season.

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).

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.

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.

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.

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.

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.

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).

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. 

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.

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.

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.

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.

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. 

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).

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).

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. 

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.

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).

A horizon: i) The surface soil horizon of a mineral soil having maximum organic matter accumulation, maximum biological activity or eluviation of materials such as iron, aluminium oxides and silicate clays. ii) A mineral horizon that formed at the surface or below an O horizon, obliterating all or much of the original rock structure and (a) characterized by an accumulation of humified organic matter intimately mixed with the mineral fraction and not dominated by properties characteristic of E horizon or B horizon. See also B horizon, C horizon.

Abatement: Refers to reducing the degree or intensity of greenhouse-gas emissions.