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Preface “Hidden hunger” or micronutrient deficiency is a pernicious problem around the world particularly in the under-developed and developing countries that is caused due to lack of vitamins and minerals in the human diet which affects the health of about three billion people worldwide. Vegetables are considered essential for well-balanced diets since they supply vitamins, minerals, dietary fibre and phyto-chemicals. In the daily diet, vegetables have been strongly associated with improvement of gastrointestinal health, good vision, reduced risk of heart disease, stroke, chronic diseases such as diabetes and some forms of cancer. Vegetable farming not only stipulates higher per capita income but also attract investment, entrepreneurship and business based on vegetable crops. India envisaged spectacular increase in the vegetable production from 15 million tonnes during 1950 to 169 million tonnes at present. However, the most critical challenge is the attainment of enhanced productivity in the farmers’ fields through input use-efficient and environment friendly manner. This book has been designed to cater the needs of undergraduates and postgraduates of State and Central Agricultural Universities studying vegetable science and horticultural science. This book has been framed to provide the principles for environmental and growth factors, seedling and graft production, nutrient and water management, organic and protected farming, crop protection, post-harvest management and marketing of vegetable crops. Every production aspect of 42 major and minor vegetable crops grown in the tropical and subtropical regions along with information regarding origin and taxonomy, importance and uses, botany, nutritional and medicinal values, plant protection measures and postharvest management have been provided. Long experience acquired through teaching and research on different aspects of vegetable science in the State Agricultural University was put to structure this book however, the contents have been enriched with the information from the number of books and research articles. I gratefully acknowledge the contribution of all the authors of those publications mentioned in the last part of the book.

Historical Account on Vegetable Cultivation in India The vegetables have chequered history in India which dates back to prehistoric period before the arrival of Aryans in India (c. 1500-1000 BC). During the pre-historic times before the arrival of Aryans in India, the Proto-Australoids (Nisada) used brinjal, bottle gourd and watermelon as vegetables. Pea existed in India much before the Aryans came to the country and it was already present in Western Asia prior to its cultivation. The pea, most likely the field pea (Pisum sativum subsp. sativum var. arvense L.) was eaten during the Harappan civilization as evidenced from the archaeological excavations of Mohenjo-daro and Harappa (2500-1750 B.C.) in which carbonized pea seeds were discovered. Pea seeds were also found from Neolithic site (last stage of the Stone age) of Chirand in Bihar (situated 10 Km south-east of Chapra), Chacolithic site (period or Copper Age) of Maheshwar Nevdatoli (c. 1200 BC.) in Madhya Pradesh and part of Osmanabad district in Maharashtra. The presence of seeds of melon along with wheat was also recorded from the Harappan excavation. Plant remains of Chenopodium album, Portulaca oleracea and a few species of Solanaceae, Polygonaceae and Labiatae family during Mesolithic times (Middle Stone Age) were found at Mesolithic site of Damdama, Uttar Pradesh (c. 7000-6000 BC). Wood charcoals of plant remains of Lablab purpureus were found from the early phase of Indus-Saraswati (Sarasvati) or Indus Ghaggar-Hakra civilization (c. 3100-2800 BC). Kundru (Coccinia indica), cowpea and field pea were recorded from Hulas in Saharanpur district, Uttar Pradesh, late Indus valley civilization archeological site. Carbonized seeds of hyacinth bean (dolichos bean), peas, Phaseolus, Vigna and melon from Rojdi in Gujarat and Chenopodium and amaranth from Surkotada, Gujarat (c. 2300-1800 BC), both being the archaeological sites belonging to the Indus valley civilization also suggested the existence of vegetables in India in the pre-historic times. Among the vegetables eaten during the pre-historic period, like brinjal, bottle gourd, watermelon, peas and melon as mentioned earlier, only brinjal has its origin in India while the other were brought from other countries much before the arrival of the Aryans. It is difficult to understand how a few important Indian native vegetables, like cucumber, Luffa (smooth and ridge gourd), pointed gourd and Dolichos bean (Lablab purpureus) were not known at that time. Similarly okra which has a secondary centre of origin in India has not been mentioned in any ancient literature. However, Abelmoschus moschatus called “Lata kasturika” in Sanskrit as a source of perfume has been recorded in Carak Samhita. The use of bottle gourd, which is not a native vegetable, is known from pre-historic times. Its dried fruit-shell is used as a hand jug (utensils) by saints and monks and in musical string instruments, like ektara, tamboora, tanpura, sitar and veena. Even mythological paintings have always delineated Naradmuni with tamboora in his hand and the goddess Saraswati with Veena which suggest the antiquity of bottle gourd in India. However, its date of introduction and the place from where it came remain unrecorded. It is also not mentioned in any iconography of the Medieval period (9th and 10th Century AD).

Food, at the fundamental level, is viewed as a source of nutrition to meet daily requirements at a minimum in order to survive but with an ever greater focus on the desire to thrive. Nutritional security denotes the consumption and physiological use of adequate quantities of safe and nutritious food by every member of the family and encompasses the process of equitable distribution among members of household and communities. This would entail the need to ensure a varied food intake, comprising all the essential macro- and micronutrients (protein, carbohydrates, minerals and vitamins), plant pigments (lycopene, β- carotene, anthocianin, lutein, capsanthin, zeaxanthin, etc.) and other functional phytochemicals (secondary metabolites, like flavonoids, isothiocyanates, glucosinolates, etc.) through a diversified diet. The growing awareness in recent years of the health promoting food has directed increased attention to vegetables as vital components of daily diets. Main Nutrient Components of Vegetables Nutrient components of our food can be grouped into five main divisions, namely, (i) Carbohydrate, (ii) Protein, (iii) Fat, (iv) Vitamins and (v) Minerals. Balanced diet is the food containing all these nutrient components in balanced form to run the physiological process in good tune. So, only eating to one’s heart’s content may not be the criterion of a balanced diet. Our dietary constitution which is mostly cereal based is really alarming. Cereals, which supply chiefly carbohydrate, constitute only a part of the diet. Moreover, the present average carbohydrate supply through cereals is also not adequate. Chief deficiencies in our diet are calories, protein, vitamin A and riboflavin. According to the studies of Indian Council of Medical Research, New Delhi and National Institute of Nutrition, Hyderabad, meager intake of vegetables, the low cost protective foods, is largely responsible for malnutrition among the majority of our population. The dieticians advocate intake of 125g leafy vegetables, 75g other vegetables and 100g root and tuber vegetables (total 300g) everyday to make our diet balanced. In households below the poverty line, per capita vegetable consumption is very low, apprehended to be even lower than 40g per day.

Classification of Vegetable Crops Vegetables are defined as herbaceous plant origin product with no calorific value and providing micronutrients, vitamins, antioxidants, fibre and alkaline reaction inside human body. Vegetable crops are not only botanically different but also their cultural and climatic adaptation also shows wide variability. It is, therefore, necessary to classify the vegetable crops for their easy recognition. Vegetable crops can conveniently be classified “Botanically” for the purpose of vegetable breeding and according to “Method of culture” from the point of crop husbandry. Botanical Classification Botanical classification involves grouping of plants into kingdom, division, sub-division, phylum, sub-phylum, class, sub-class, order, family, genera, species, sub-species and variety. The broadest group in which vegetables are discussed is family. The genus and species constitute the scientific name. Scientific names are accepted worldwide and there cannot be any confusion as per their nomenclature. All vegetable crops belong to the division Angiospermae. The division Angiospermae has two classes: Monocotyledoneae and Dicotyledoneae. The crops used for vegetable purpose in the world belong to 1200 species under 78 families and of them, more than 860 species under 59 families belong to dicotyledoneae and about 340 species under 19 families belong to monocotyledoneae. In the tropical and subtropical parts of the world, about 90 species of vegetable crops are cultivated, but hardly 25 of them are commercially important in terms of market demand, development of variety/hybrid and seed production. In the present botanical classification, over 140 different kinds of vegetable crops under 7 monocotyledoneae and 20 dicotyledoneae families have been included.

Development can be defined as the process and timing of differentiation of the component events causing qualitative changes in form and function of the plant and therefore, manifestation of economic plant parts. Sowing is the beginning of the process, after which plants emerge, grow and develop with or without transplanting and may be harvested in vegetative (e.g., cole, bulb, tuber, root, salad crops) or reproductive phase (solanaceous fruits, peas and beans, cucurbits, okra, etc.). Growth and development of plants is dependent on abiotic (physical) and biotic (biological) factors. Abiotic factors include the physical environmental conditions and biotic factors include animals, insects, and diseases. Each plant has certain environmental requirements. To attain the highest potential yields a crop must be grown in an environment that meets these requirements. A crop can be grown with minimal adjustments if it is well matched with its climate or growing condition. Unfavourable environmental conditions can produce a stress on plants resulting in lower yield. In such cases the environment can be artificially modified, as done in protected structures like poly house, shade net house, etc. to meet the crop requirements. Different abiotic environmental factors viz., light, temperature, water and soil greatly influence plant growth and geographic distribution. These factors determine the suitability of a crop for a particular location, cropping pattern, management practices, and levels of inputs needed. A crop performs best and is least costly to produce if it is grown under the most favourable environmental conditions. To maximize the production of any crop, it is important to understand how these environmental factors affect plant growth and development.

The term ‘Phyto-hormone’ was coined by Thimann in 1948. Phyto-hormones are organic compounds, which are produced naturally in plants, synthesised in one part and usually translocated to the other part where in every small quantity affect the growth and other physiological function of the plants. Auxin was the first hormone to be discovered in plants. At one time, auxin was considered to be the only naturally occurring plant growth hormone however, four other classes of phyto-hormone viz., gibberellins, cytokinin, ethylene and abscisic acid was later discovered. Plant growth regulators include both five specified classes of phyto-hormones (auxin, gibberellins, cytokinin, ethylene and abscisic acid) and other synthetic organic compounds (for example, polyethylene glycol, dinoseb-2-sec butyl 4,6dinitrophenol, proteins and/or amino acids, carboxylic, phenolic acid, humic acids, etc.) having properties of bio-stimulants or bio-inhibitors. Plant growth regulators (PGRs) modify plant physiological processes either by stimulating or inhibiting specific enzymes or enzyme systems to help regulate plant metabolism and thereby enhance yield and product quality. They normally are active at very low concentrations in plants. Importance of PGRs was first recognized in the 1930s. Since then, wide array of natural and synthetic compounds that alter function, shape and size of crop plants have been discovered. Of the many uses of PGRs, effects on yield are often indirect. A wide range of beneficial effects of PGRs on crop growth and yields are: 1. promotion of germination and/or emergence, 2. stimulation of root growth, 3. promotion, mobilization and translocation of nutrients within plants, 4. modification of flowering, 5. increase in stress tolerance and improvement of water relations in plants, 6. promotion of early maturity, 7. increase in disease resistance, 8. retardation of senescence and 9. improvement of crop yields and/or quality.

It is said that “Success of any production system depends on the kind of seed which are sowing”. It is true for the seedlings also beacause healthy seedlings grown in a well managed nursery will decide the yield and consequently the profit. Definition of Vegetable Nursery A vegetable nursery is a place or an establishment for raising or handling of young vegetable seedlings until they are ready for more permanent planting. Why vegetable nursery is needed Some vegetable crops require special cares during their early growth period. There are some vegetables with very small sized seeds. Seedlings of many seed propagated vegetable crops like, tomato, brinjal, chillies, sweet pepper, cauliflower, cabbage, knolkhol, broccoli, Brussels sprout, kale, endive, chicory, celery, lettuce, parsley, onion, etc. are first raised in the nursery beds before transplanted in the main field. Many seed propagated vegetable crops viz., okra, peas, beans, radish, carrot, beet, turnip and all the cucurbits (e.g. bitter gourd, bottle gourd, pumpkin, cucumber, watermelon, muskmelon, snake gourd, sponge gourd, ridge gourd, etc.) are conventionally grown through direct seeding in the main field. However, many cucurbits, particularly in the early season are also grown in India using the seedlings raised in polythene packets.

Plant nutrition is the study of the chemical elements and compounds necessary for plant growth, plant metabolism and their external supply. In 1972, Emanuel Epstein defined two criteria for an element to be essential for plant growth: In its absence the plant is unable to complete a normal life cycle. The element is part of some essential plant constituent or metabolite. This is in accordance with Justus von Liebig’s law of the minimum. The essential plant nutrients include carbon, oxygen and hydrogen which are absorbed from the air, whereas other nutrients including nitrogen are typically obtained from the soil.

Relationship Between Plant and Water Water is the most vital component of the living cells and the basis of plant feeding. Water is also characterized with extraordinary physical properties: it has high specific heat, biggest latent heat of vaporization, very high thermal conductivity and greatest surface tension. Large amounts of heat are tied up with water because of very high specific heat, which contribute to both climatic stability and to heat budgets of the plants and other organisms. Water molecules are integral part of living systems being the solvent for metabolites and structural component of proteins and nucleic acids. In fact, biological macro-molecules cannot exist in their complicated secondary folding or spiralled helixes without the support of hydrogen bonding within their water matrix. The water matrix is also critical for metabolic activity because its properties of hydration permit ready reactivity between molecules in solution as well as between enzymes and their substrates, and the biochemical processes are sensitive to tissue hydration. A reduction of only 20-25 per cent below maximum hydration is sufficient to cause metabolic malfunctioning of many enzymes. It is the substrate for photosynthesis and a product of respiration. Water also helps to buffer plant tissue against fluctuations in the external environment. Plant growth including leaf expansion, organ enlargement, reproductive development and stomata function are all clearly associated with moisture status. Hormonal changes (abscisic acid and cytokinins) in plant body occur with brief reduction in water potential. Water is the also major force in shaping the climatic patterns.

Most of the insect pest and disease (insects, mites, diseases, nematodes, etc.) management problems arise from relying entirely on pesticides for control. Integrated pest management (IPM) is a strategy that draws on a range of management tools with the goal of using the least ecologically disruptive techniques to manage pests within economically acceptable levels. IPM considers the production system in a holistic manner and looks at all aspects of the farming enterprise as potentially increasing or decreasing pest numbers and, where possible, enhancing the activities that reduce these pest populations. Strategy for Integrated Pest and Disease Management The basic IPM strategy involves routine crop monitoring to ensure that pesticides are only applied when needed, as well as to ensure appropriate timing of pesticide applications. The most developed bio-intensive IPM relies primarily on beneficial organisms to manage insect pests. When greater pest control is needed, interventions chosen are complementary to the survival of these beneficial organisms. As other pests are incorporated more and more prevention strategies are adopted which reduces the need for direct control practices.

Weeds are unwanted and undesirable plants which interfere with the utilization of land and water resources and thus adversely affect crop production. Classification of Weeds Weeds can be classified in three different manner based on morphology, life cycle, habitat and origin.

Green revolution technologies such as greater use of synthetic agrochemicals like fertilizers and pesticides, adoption of nutrient-responsive, high-yielding varieties of crops, greater exploitation of irrigation potentials etc. has boosted the production output in most cases. However, continuous use of these high energy inputs indiscriminately now leads to decline in production and productivity of various crops as well as deterioration of soil health and environments.

Protected cultivation can be defined as a cropping technique wherein the micro-climate surrounding the plant is controlled partially or fully as per the requirement of the plant species during their growth period. This cropping technique is the most modern approach to grow different horticultural crops mainly, vegetable crops and flowers for enhancement of both productivity and product quality. This technology has spread extensively the world over in the last few decades. This technology involves the cultivation of different crops particularly, horticultural crops in a controlled environment wherein the environmental parameters like the temperature, humidity, light, soil, water, plant nutrition, etc. are manipulated for enhancement of production as well as product quality even during off-season which ensures additional return to the growers.

Potato Potato, Solanum tuberosum L. under the family Solanaceae (Chromosome No. 2n = 4x = 48) is the most important non-grain food crop in the world, ranking 3rd in terms of total production with over 381 million tonnes per year in (FAOSTAT, 2017), after rice and wheat. It is grown in 150 countries spread across both temperate and tropical regions and at elevations from sea level to 4,000 m. It is extensively cultivated in China, Russian Federation, Ukarine, Poland, Ireland, Great Britain, Germany, Netherlands, France, Spain, South America, India and USA. Potato was brought from Peru to Spain by the Spaniards in 1565 when it was widely grown in Spain and Italy. They were probably brought to England in 1586 by Sir Francis Drake. Potato was introduced in India in early 17th century probably by the Portuguese. Now it is one of the principal cash crops of India. The crop The subsection Potato is distinguished from all other subsections within the genus Solanum by “true potatoes whose tubers are borne on underground stolons, which are true stems, not roots”. The series tuberosa is characterised by “imparipinnate or simple leaves, forked peduncle, rotate to pentagonal corolla and round berries”. The species S.tuberosum is characterised by “pedicel articulation placed in the middle third, short calyx lobes arranged regularly, leaves often slightly arched, leaflets always ovate to lanceolate, about twice as long as broad, tubers with well marked dormancy period” Potato is an annual herbaceous plant and growth habit varies between and within species. The plant has a rosette or semi-rosette habit. The stem is erect in the early stage but becomes spreading and prostrate later on. The leaves are compound and alternate, irregularly odd pinnate. The tuber is an enlarged portion of an underground stem or stolon. Tuber eyes are the buds from which next season’s growth will emerge. Eyes are concentrated near the apical end of the tuber, with fewer near the stolon or basal end. Eye number and distribution are characteristic of the variety. Potato is mainly propagated vegetatively by means of tubers and sometimes by botanical seeds, i.e., true potato seeds. Potato has a terminal inflorescence consisting of 1-30 (but usually 7-15) flowers, depending on the cultivar. The five petals give the open flower a star shape. A flower also has a pistil that generally protrudes above a cluster of five large, bright yellow anthers. The corolla colour varies from white to complex range of blue, red and purple. Flowers are self-pollinated but also cross pollination take place by insect. Seeds are produced in the fruit which is botanically called berry. Potato fruits, stems and leaves contain glycoalkaloids, the toxic compounds, of which the most prevalent are solanine and chaconine.

Cropping system is defined as the cropping pattern followed on a farm and its interactions with farm resources, other farm enterprises and production technology. The yearly sequence and spatial arrangement of crops and fallow on a given area is termed as cropping pattern. India has over 17% of world’s population living on 2.4% of the world’s geographical area. Per capita agricultural land has reduced by 67% from 0.48 ha in 1951 to 0.16 ha in 2008 due to explosive increase in population. In this situation, it is very difficult to get horizontal expansion in vegetable cultivation. Hence, total production per unit area can be increased by increasing the productivity per unit area through (a) growing improved high yielding varieties and hybrids, (b) adequate and scientific crop management practices and (c) increasing cropping intensities following different cropping patterns.

Quality Components of the Produce Various components of quality are used to evaluate the products in relation to specific grades and standards and responses to various environmental factors and post-harvest treatments. The relative importance of each factor depends upon the commodity and its intended use, fresh or processed. The main quality components of vegetables are mentioned below

Marketing is one of the most important factors in determining the success of any vegetable farming enterprise. Marketing includes all the operations and decisions taken by the producers. These decisions range from determining the most marketable crops for production to deciding how to best deliver quality produce to the consumers at a profit. However, contrary to popular belief, marketing does not begin after a crop is produced. Instead, marketing alternatives need to be considered even before the start of production. However, vegetable marketing in India has not yet been organised so far. The long route from the grower to the retailer and ultimately to the consumer involves a chain of middlemen, transport contractors and wholesale merchants. Very often, there arises stagnation of the produce in the peak season or in the year of good production. The large number of intermediaries in the vegetable marketing channel grab maximum share of the consumer’s price and as a result, the producers’ profit becomes marginal. Vegetable cultivation is a capital intensive venture, and huge production alone cannot fetch profit for the growers. Organised marketing, storage and transport facilities are the key factors for making vegetable farming profitable which ultimatily boost vegetable cultivation.

References Bautista, O.K. and Mabesa, R.C. (Eds). 1977. Vegetable production. University of the Philippines, Los Banos. Philippines. Bernard, O.L. (Ed.). 1979. Hawk’s Physiological Chemistry, Tata McGraw Hill. Bhat, K.L. 2007.Minor vegetables, Untapped Potential, .Kalyani Publishers, Ludhiana. Bose, T. K. and Som, M.G. 1986. Vegetable Crops in India , Naya Prokash, Calcutta. Brady, N.C. 1980. The Nature and Properties of Soil. MacMillan Publishing House, INC., USA. Brown, H.D. and Hutchison, C.S. 1949. Vegetable Science, J.B. Lippincott Co., New York. Butani, D.K. and Jotwani, M.G. 1984. Insects in Vegetables, Periodical Expert Book Agency, Delhi. Byrne, R. and McAndrews, J. H. 1975. Pre-Columbian puslane (Portulaca oleracea L.) in the New World. Nature, 253(5494): 726–727. Celine, V. A. 2012. Drumstick. In: Hand book of Vegetables (Eds. Peter, K.V. and Hazra, P.), Studium Press LLC, Houston, Texas, USA, pp. 231-256. Chatterjee, B.N., Maiti, S. and Mandal, B.K.1989. Cropping Systems- Theory and Practice, Oxford & IBH. Chattopadhyay. A. and Hazra, P. 2008. Cluster bean. In: Scientific Cultivation of Vegetables (ed. Rana, M. K), Kalyani Publishers, Ludhiana, pp. 48-61. Dixon, G.R. 2007. Vegetable Brassicas and related Crucifers. CABI, Wallingford, UK, 327p. Donahue, R.L., Miller, R.W. and Shickluna, J.C. 1990. Soils: An Introduction to Soils and Plant Growth, Prentice-Hall of India.