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Since the dawn of civilization, the human species had an intimate association with fruits, roots, nuts and other vegetables that sustained them through the ages. This mutualism continued and flourished through domestication and organized culture of horticultural crops. Pretty long before, homestead gardening had been evolved in different parts of the globe independently to become a part of tradition in almost every society. Plant domestication by all likelihoods started around the human settlements. The obvious reasons for this were man’s need, better supply of water and organic household wastes and protection against destruction or grazing by animals, that’s why the prospective horticultural enterprise of homestead gardens all over the world is still the most enduring and sustainable form of family food production system and very important micro-units for conservation of plant genetic resources. The traditional and indigenous endeavour of the tribal people for conservation of land races also noteworthy contribution from one generation to the next. Though cereals are staples for most of the world population, there has been sustained emphasis on horticultural crops, particularly vegetables, all over the world during last few decades. The possible reasons are:

The basic feature of the Pre-British India was a village, which was economically a water-tight compartment fulfilling the three basic functions of economy, i.e., production, distribution and consumption, within the village community without outside world dependence, except the salt and kerosene. Every village was a self-sufficient unit with dependence on agriculture carried out by community people of different castes having the occupational specialization with interdependence, viz. jajmani system and alike.

Developments in the means of communications and the opening of Suez Canal in 1869 introduced fundamental and far-reaching changes in the social system and economic life of Indians by transforming self-sufficient village economy to new modes and means based on competition, market and price mechanism. This change was deliberated by Britishers for meeting the requirement of raw material and the diversification to tea, jute and indigo took place. Cotton also got importance but agriculture did not find place for vegetables. Famines were very common and crop production depended on monsoon rains to the large extent. Britishers developed cotton, jute and mineral trade for their vested interests.

Britishers emphasized the development of railways for better mobility of their troops, commercial crop produce and minerals but the Report of Famine Commission 1901 bitterly criticized the Government for the step-motherly treatment given to irrigation facilities as compared to railways. The irrigation policy of the Government in 19th century was determined purely from concerns for adequate returns on investment and profit was of Rs. 81 lakhs after paying 4% interest on amount invested on irrigation development in 1896-97. Irrigation Commission was established and a sum of Rs. 42 crore was spent on irrigation by 1911. By 1930, about 30 million acres were brought under canal irrigation, which was far larger than the irrigated area in any other country of the world. Even in the USA, the area under canal irrigation was two-third that of India. Vegetables cultivation did not find place in Indian agriculture and also in diet of villagers. Their cultivation remained restricted to the periphery of the urban centres for meeting the demand of upper class elites only.

Agriculture is a generic term used to include various types of farming systems, single to multiple crops under various agro-climatic conditions thereby covering crop husbandry, animal husbandry, vegetable growing, floriculture, horticulture, fishery, poultry, goat rearing, piggery, rabbit rearing, sericulture, forestry, vermi-composting, etc. Indian agriculture is a symbiosis of various production systems, a way of life or a tradition, which for the centuries have shaped the thoughts, the outlook, the culture, and the social and economic force of rural life. It is well known for its multi-functionalities of providing employment, cultural heritage, livelihood, social security, family bondage, nutritional and food security. Although agriculture is the main stay of the Indian economy and supports nearly two-third of the work force, yet this is not a highly rewarding enterprise for a large majority of farmers who hold small and marginal size holding. At the same time, the size of the land holding is on a gradual decline, while contribution of farmwomen is on an increase as men go elsewhere in search of better jobs. This sector holds and will continue to be central to all strategies of socio-economic development of the country. A farmer is a multi-purpose entrepreneur (Rajavanshi, 2007).

The importance of vegetables in human nutrition is now well known all over the world. Vegetables are rich and comparatively cheaper source of minerals and vitamins. Their consumption in sufficient quantities provides taste and palatability, increases appetite and provides fair amount of fibre. Besides, they provide many specific chemical substances, which are essential for growth, reproduction and for the maintenance of good health and also beneficial in protecting against some degenerative diseases (Prior and Cao, 2000; David, 2005; Elison and Levin, 2006).

Apart from their nutritive value, vegetables probably do more than any other groups of food to add colour, texture and flavour to our daily diet. Majority of the population in India is vegetarian, and thus, vegetables form an essential item of food for both the rich and the poor people. National Nutrition Monitoring Bureau (1997) surveys indicated that the daily intake of most foodstuffs in Indian households, except for cereals and millets, is much below the recommended dietary allowances (RDA). The diets provided negligible amount of protective foods. It was found that consumption of green leafy vegetables (< 10 g) and other vegetables (70-80 g) per day, which are rich source of micronutrients, are woefully inadequate. However, as per the RDA, an adult man should consume 200 g roots and tubers, 100 g green leafy vegetables and 100 g other vegetables (Table 1) in a day. In addition, fresh fruits (100 g) as available in different seasons should be consumed regularly for the prevention of chronic diseases (NIN, 1998).

Olericulture, a Latin word, is used to designate the science, culture and management of vegetable crops. In India, about more than fifty vegetable crops are grown in different parts, depending on their climatic requirement. A number of vegetables have similarity in their method of cultivation, which makes the package of practices followed by the farmers for their cultivation very complicated and brings about a lot of repetition. Whichever the method is adopted for the classification of vegetables can systematize the preparation and presentation of the material to some extent and can avoid the unnecessary duplication of some of the principles and methods of vegetable cultivation. In different vegetables, different plant parts are used as food in different forms and they belong to different botanical families with varying cultural and climatic requirements but common insect-pests and diseases along with their common control measures.

Various methods may be used to classify all the vegetable crops into different categories but no single method of classification would be useful to serve the purpose for different groups of scientists like taxonomists, botanists, physiologists, horticulturists, agronomists, and breeders. Under field conditions, the classification based on cultural practices has been proved the best adaptable and very useful for the growers. Vegetable crops can be classified in the following ways for the convenience of different groups of scientist and growers:

Olericulture, a Latin word, is used to designate the science, culture and management of vegetable crops. In India, about more than fifty vegetable crops are grown in different parts, depending on their climatic requirement. A number of vegetables have similarity in their method of cultivation, which makes the package of practices followed by the farmers for their cultivation very complicated and brings about a lot of repetition. Whichever the method is adopted for the classification of vegetables can systematize the preparation and presentation of the material to some extent and can avoid the unnecessary duplication of some of the principles and methods of vegetable cultivation. In different vegetables, different plant parts are used as food in different forms and they belong to different botanical families with varying cultural and climatic requirements but common insect-pests and diseases along with their common control measures.

Various methods may be used to classify all the vegetable crops into different categories but no single method of classification would be useful to serve the purpose for different groups of scientists like taxonomists, botanists, physiologists, horticulturists, agronomists, and breeders. Under field conditions, the classification based on cultural practices has been proved the best adaptable and very useful for the growers. Vegetable crops can be classified in the following ways for the convenience of different groups of scientist and growers:

In view of fast development of industrial sector and rapid urbanization, the vegetable gardening of various types has great scope for providing food and nutritional security, promoting health, solving employment problem and raising the economic status of an individual and the country as a whole. In many of the developing countries, protein-energy malnutrition is the most important health problem, which has long-term ailing consequences. Iron and vitamin A deficiencies are also potent contributors towards morbidity, mortality, underweight and stunted growth of individuals. Vegetables from homestead gardens can combat these dreaded social nuisances. In many cases, indigenous vegetables, gathered or grown wild, are more nutritious than foreign high value exotic species (Drescher, 1998). Various types of vegetable farming are being practiced the world over depending on the area available and objectives for the disposal of the produce. Based on the mode of disposal, the vegetable gardening can be categorized into two types:

The importance of fruits and vegetables in human nutrition is well known. Vegetables are a rich and comparatively cheaper source of minerals and vitamins. Besides, their consumption in sufficient quantities provides taste and palatability, increases appetite and provides a fair amount of fibers. These are currently reckoned as an important adjunct for the maintenance of good health and beneficial in protecting against some degenerative diseases, thus, they form a vital part of human diet. Besides, vegetables now a day are being considered as an asset for providing a good source of income to the growers.

Vegetables originated in different parts of the world, some came from tropical or subtropical countries and others from temperate zones, some from humid areas and others from climates that are more arid. Most of the countries in the world are gifted with varied agro-climatic environments for growing an array of vegetable crops to combat the present imbalanced diet of a vast population of the world, particularly in the developing countries. Production of vegetables in developed countries is much higher, for instance in Japan, nearly 40% of the diet of the people is vegetables. To meet out the full dietary needs of the common man, to eliminate malnutrition, deficiency of minerals and vitamins and also to relieve the stress for increased production of cereals, there is a greater need for growing vegetables on larger scale. As such, for increased production of nearly 247 known vegetable crops, a sound knowledge of the various aspects of vegetable production technology, environmental stresses and constraints, techniques of raising, pre- and post-harvest technology, marketing and seed production techniques is of utmost importance. Breeding and selection of new cultivars have allowed for a greater adaptability to less favourable growing conditions than was possible in the past but the inherent agroclimatic requirements of a specific kind of vegetable have not changed materially. Time or season of planting of a particular vegetable crop is determined by its environmental requirement. Knowledge of specific agroclimatic conditions required for a particular crop could enable the grower to select the best season of planting in any particular area (Singh et al., 1991).

Seed is the basic input of agriculture, and its importance has now well recognized in the food supply chain since the warranty for production could be succeeded only based on the availability of seed. Seed becomes the quality seed, on possession of specific characters, viz. germination, vigour, purity and health status, hence, seed production becomes the specified scientific technology with the foreseeing of quality and storability in addition to productivity. From time immemorial, seeds are being imposed with some management techniques for improvement in seed quality and thereby the productivity. These seed management techniques are known as seed treatments. Generally, seed treatment is the application of biological, chemical agents and physical techniques to the seed in order to obtain the benefit of plant protection, production and invigouration. Basically, seed treatments are intended to improve the quality of seeds since nothing can substitute poor quality seed, no matter how lavishly other inputs are spent on the crop established from such seeds. Even for a resource poor farmer, high quality seed would be a great advantage because it ensures the best utility of all inputs in addition to the augmentation of yield increase by 15 to 20%.

In general, seed treatment could broadly be classified into physical and physiological treatment. Physical treatment is external seed treatment, while physiological is impregnation of needy substances into the seed through various seed management techniques. Some of the germination augmenting physiological seed treatments are seed fortification, seed hardening, seed priming, dry permeation and pre-germination. In addition, some of the seeds are imposed with special treatments such as dormancy breaking treatment such as soaking in water, mechanical scarification, acid scarification, bio-scarification, scorching, warm stratification, cold stratification and electrical seed treatment. The common physical seed treatments are seed pelleting, seed coating/film coating and seed colouring. Seeds are also imposed with some other physical treatments that can act on the physiology of the seed such as irradiation, magnetic and electrical seed treatment. In addition, irrespective of seed, seeds are given with protective treatment when they are taken for storage, which are commonly termed as pesticide seed treatment. Seeds are also given with corrective treatment at their initiation reduction with seed quality characters during storage, which are termed as mid storage correction.

Nursery management is indeed a very important operation in successful growing of vegetables especially those, which are raised through seedlings in properly managed nursery beds. Raising nursery from seed provides an easy and convenient way to nourish tender young seedlings in a well-managed small and compact area. The nursery area can be conveniently protected from natural hazards, seed borne diseases and insect-pests and can be well managed economically. Some of the vegetable seeds are very costly, for which it is necessary to raise nursery in the most-optimum conditions. In areas where land holdings are small (in hills), nursery raising helps in making economical use of land for about one month and provides enough time to mature for previous crop, harvesting, threshing and land preparation for next crop. Most of the vegetable crops like cabbage, cauliflower, tomato, eggplant, sweet pepper, hot pepper, onion, celery, parsley, lettuce, etc. can successfully be raised through seed by growing them in the nursery and then transplanting in the field.

“A vegetable nursery is a place or an establishment for raising or handling young vegetable seedlings until they are ready for more permanent planting.”

Nursery can be maintained either for personal or commercial purpose, and each has its own advantages and disadvantages. Seedlings raised for own planting will be true to type, sound and healthy. On the other hand, seedlings purchased from outside may not be true to type, vigorous and healthy and may not arrive at destination in due course of time.

After attaining green revolution, nutritional security is of utmost importance in the current agricultural scenario. Vegetables play a key role in providing nutritional security in the country. They are important and readily available source of mineral nutrients and vitamins and play a vital role in the financial economy of the majority of small and marginal farmers. Further, these roles are becoming more transparent in the light of agriculture diversification as the vegetables have many agro-economic advantages and can fit into varying cropping systems under diversified conditions. After China, India is a leading vegetable producer but the productivity of vegetables per unit area is very low compared to other developed countries. Poor crop stand establishment is one of the factors responsible for low productivity. Yield and productivity can be improved by using advanced technology on the field preparation, optimum sowing conditions, correct nursery practices and planting methods.

Almost all the vegetable crops are propagated by seed, except a few. Crops are raised either by direct seeding in the field or by transplanting seedlings raised in nurseries. Direct seeding is the placement of seeds at desired depth into the final location where soil environment is ideal for optimum germination and crop stand establishment. On the other side, transplanting refers to removal of actively growing seedlings from one place to another with the purpose of having them continue their growth in the new location until harvest.

The vegetable crops like peas, beans, cowpea, okra, beet leaf, spinach, fenugreek, coriander, carrot, radish, turnip, beetroot, etc. are sown directly in the field, while tomato, eggplant, hot pepper, sweet pepper, onion, leek, sweet potato, cabbage, cauliflower, broccoli, Brussels sprout, kohlrabi, kale, lettuce, celery, parsley, rhubarb, squashes, etc. are first sown in the nursery beds where seedlings are raised and then transplanted in the main field. Both direct seeding and transplanting are practiced in most of the cucurbits like gourds, cucumber, melons and pumpkin.

The directly sown vegetable crops do not respond to transplanting because their embryonic roots do not produce lateral fibrous roots after uprooting unlike transplanted crops where numerous fibrous roots are generated, thus, making the plant to absorb more nutrients.

Soil fertility and crop production can be maintained only by efficient and judicious management of nutrients addition to the soil from external sources. Of the two sources most widely used all over the world, one is organic in nature- the organic manures, simply called manures, and the other comprises the synthetic or naturally occurring chemical fertilizers, simply called fertilizers. A brief account of manures is described hereunder:

The word manure came from Middle English manuren meaning to cultivate land, and initially, from French word manoeuvre meaning hand work alluding to the work which involved manuring land. The term manure originally meant that which was worked by hand (Fr. manoeuvre), but gradually, came to apply to any process by which the soil peroperties could be improved. Prominent among such processes was that of directly applying manure to the land, manure in this sense being what is now called farmyard manure or dung, the excreta of farm animals mixed with straw or other litter. Ronald Fisher seems to have used the word manure systematically for what we would call fertilizer today.

Uses of Manure

Manure has been used for centuries as a fertilizer for farming since it is rich in nitrogen and other nutrients, which facilitate growth of the plants. Liquid manure from pig or hog operations is usually knifed (injected) directly into the soil to reduce the unpleasant odours. Manure prepared from hogs and cattle is spread on fields using a manure spreader. Due to the relatively lower level of proteins in grasses, which herbivores eat, cattle manure has a milder smell than the dung of carnivores, e.g., elephant dung is practically odourless. However, due to the quantity of manure applied to fields, odour can be a problem in some agricultural regions. Poultry droppings are harmful to plants when fresh but after a period of composting are valuable fertilizers.

The dried manure of animals has been used as fuel throughout history. Dried manure (usually known as dung) of cow was and still is an important fuel source in countries such as India, while camel dung may be used in treeless regions such as deserts.

Many materials can be applied to the soil as source of plant nutrients but the term fertilizer is often used to refer to relatively soluble nutrient sources with a high analysis or concentration. Commercially available fertilizers supply essential elements in a variety of chemical forms but many are relatively simple inorganic salts. Advantages of commercial fertilizers are their high water solubility, immediate availability to the plants, high concentration and low price per unit of nutrient, and the uniformity and accuracy with which specific amounts of available nutrients can be applied. Since they are relatively homogeneous compounds of fixed and known composition, it is fairly easy to calculate precise application rates and attain relatively consistent performance. This is in contrast to organic nutrient sources, which are a much greater challenge to manage because of their variable composition, variable nutrient availability and patterns of nutrient release that are greatly affected by temperature, moisture and other conditions that alter biological activity.

The solubility of commercial fertilizers can sometimes be a problem since soluble nutrients may move out of farm fields when applied in excess or large rains occur soon after fertilizer application. Soluble nutrients can be lost by leaching on well-drained soils and through tile outlets or in runoff on poorly drained soils. Denitrification can cause large losses of nitrate-N from water-saturated soils in wet springs.

Increasing soil cation exchange capacity by increasing organic matter reduces the movement and loss of some nutrients, although not nitrate-N (an anion). Management practices that synchronize nutrient availability with crop demand and uptake also minimize losses. Both application timing and the amount of fertilizer applied are important. Splitting fertilizer application into several small applications rather than a single large one is especially important to limit nitrogen leaching on well-drained sandy soils. Split nitrogen applications can also reduce nitrogen losses in runoff or from denitrification on poorly drained soils. Excess nutrient applications can be eliminated or at least significantly reduced by soil testing on a regular basis, setting realistic yield goals and fertilizing accordingly, accounting for all nutrient sources such as legumes, manure and other amendments and using plant analysis as a monitoring tool for the fertilizer program.

Increasing food need, decreasing land availability and concurrently attenuating synthetic nutrients supply envisage the use of alternate supplementary inputs for the cultivation of crops. India is among the few nations where systematic farming started thousands of years ago. It was not only the source of income but was also a way of life. Agricultural activities and the techniques adapted to suit local needs and conditions. Different farming systems were followed by the farmers in different areas according to their needs and weather conditions. The produce was usually shared with other communities of the society involved in other professions. Almost all the nutrients removed by the crops were recycled to the soil directly or indirectly (Yadav and Mowade, 2005). In economic terms, the system followed by the then farming community was highly cost effective since all the inputs needed were locally available and practically no expenditure was incurred except labour. The traditional agriculture was though less productive but self-sufficient. With the advent of modern scientific discoveries, agriculture also changed its face, and with the introduction of high yielding varieties, synthetic fertilizers and effective plant protection measures through chemicals, Indian agriculture made rapid strides in the shape of Green Revolution. As an upshot of Green Revolution, the grain production increased two and a half folds in about three decades with a marginal increase in net-area under cultivation.

India is a major exporter of vegetables with 10th position in the world. In the past, the Dexport of Indian vegetables was restricted to potatoes and fresh onions, however, now, the Government of India finds great opportunities for expanding exports of several vegetables including lettuce, fresh peppers, tomatoes, squashes, gherkins, etc. Under World Trade Organization (WTO) regime, the development of stronger seed industry and improved production technology will give India a competitive edge in global market. New opportunities and challenges are emerging every day in the dynamic and global vegetable-based industries. However, such opportunities can be harnessed only if assured quality, in terms of organic farming and reduced pesticide residues, is maintained (Shanmugasundaram, 2004).

Mulching is a practice of covering the surface of soil with plastics, organic and non-organic materials like straw, grasses, sands, stones (boulders), synthetic plastics, etc. to reduce evaporation and to moderate wide fluctuations in diurnal soil temperature, especially in the root zone environment. It controls external evaporability and reduces energy supply to the evaporating site by cutting off solar radiation falling on the ground. Its main function is limited to control first stage of drying, which helps in improving moisture status and reducing soil temperature (Loy and Wells, 1975), besides checking seedling mortality and improving crop stand. It also suppresses weed-flora and reduces weed competition with crop for water and nutrients making them available in greater quantities for crop plants. Moreover, mulching helps in increasing downward movement of water, and its storage deep in the profiles escapes evaporation due to reduction in thermal gradients and exchange of vapours. The effectiveness of mulches in conserving moisture has generally been found to be higher under more frequency of rainfall, drought conditions and also during early period of plant growth when canopy cover remains scanty.

Most of us consider weeds to be the troublesome, competitive, aggressive, undesirable, unsightly elements of the plant world. We hate weeds since desirable plants cultivated by us are deprived of food, water, sunlight and space by these plants. They can easily colonize an area and thrive even under non-ideal conditions of growth and may affect human welfare adversely. It is perhaps due to this that the saying, when weeds win all the people lose, has come into existence.

The terminology committee of the Weed Society of America gives the simple definition of weed as a plant growing where it is not desired. King (1974) in his book Weeds of the World observed that ‘‘a plant classed as a weed in one region where it has few, if any, uses may when growing in another region, possess some very valuable uses, or in few cases may actually be cultivated’’. For instance, Bermuda grass (Cynodon dactylon) is a highly troublesome weed in crop fields, but in village pastures, it is a much sought for forage grass. Quack grass (Agropyron repens) is a very good soil binding grass on erodable non-crop lands but it is a serious weed when it infests crop fields and orchards. Campbell (1923) considered weeds as ‘honest, independent competitors for food materials in the struggle for existence’. He pointed out that the term, weed has developed in the minds of people not according to specific qualities or by a definite concept in the mind of man, but by human caprice, e.g., corn is a cultivated crop, hence, desirable plant in a corn field. However, if a corn plant grows in a Soya bean field, it is considered a weed by the Soyabean farmer. Sometimes, two persons may differ about the weedy nature of a plant at the same place and time, e.g., water hyacinth (Eichhornia crassipes) is a weed for fisherman but it is a plant of aesthetic value for a city dweller.

Thus, a corollary to the above definitions of weed is that weeds are those plants, which grow out of their place, interfere with the utilization of natural resources, prolific, persistent, resistant, competitive, harmful and even poisonous in nature and can grow under adverse conditions.