eChapters

12.1. Tea

12.1.1. Algal leaf spot: Cephaleuros virescens

Symptoms

• Leaves develop lesions that are roughly circular, raised and purple to reddish brown.

Management

• Removal of infected portions and spraying of Bordeaux mixture

• Improving soil nutrient status by application of nitrogen, phosphorus and potassium

12.1.2. Brown blight, grey blight: Colletotrichum sp., Pestalotiopsis sp.

11.1. Tea

11.1.1. Tea mosquito bug: Helopeltis theivora

Symptoms

• Adults and nymphs suck sap from buds, young leaves and tender stems.

• Punctures appear as reddish brown spots.

• Leaves curl up, badly deformed and shoots dry up.

Management

• Spray clothianidin 50 WDG 120 g/ha or thiacloprid 21.7 SC 375 ml/ha or thiamethoxam 25 WG 100g/ha or bifenthrin 8 SC 500 ml/ha.

10.1. Origin and distribution

• Native to the tropical Africa and grows in the Nepal, India, Bangladesh, Sri Lanka, Cambodia, Laos, Myanmar, Thailand, Vietnam, Malaysia, Indonesia and the Philippines.

• Palm is widespread in Tamil Nadu, Kerala, Andhra Pradesh, Telangana, Odisha, West Bengal, Bihar, Jharkhand, Karnataka and Maharashtra.

• In Tamil Nadu, it is present in Tuticorin, Tirunelveli, Thenkasi, Virudhunagar, Ramanathapuram Madurai, Theni, Salem, Namakkal, Kancheepuram, Chengalpattu, Tiruvallur, Villupuram, Kallakurichi and Cuddalore districts.

• Palm is dioecious in nature.

• Palmyrah was declared as “State Tree of Tamil Nadu” by the Government of Tamil Nadu.

.1. Origin and distribution

• Originated from West Africa.

• Cultivated in Malaysia, Indonesia, USA, Cameroon, Cote d’Ivoire, Ghana, Liberia, Nigeria, Sierra Leone, Togo, Angola and Congo.

• Commercial scale plantation in Malaysia was found in 1917.

9.2. Economic importance

• Produces edible palm oil as well as palm kernel oil.

• Maj or constituent of oil is mono unsaturated oleic acid; rich in carotenoids.

• Unrefined palm oil is a significant source of tocotrienol, part of vitamin E.

• Oil content is 17 to 27% for palm oil, and 4 to 10% for palm kernels.

8.1. Origin and distribution

• Originated in South and South East Asia.

• Cultivated mostly from Pakistan to Papua New Guinea.

8.2. Economic importance

• In India and Sri Lanka, sheaf of betel leaves are traditionally offered as a mark of respect and auspicious beginnings like greeting elders at wedding ceremonies, celebrating the New Year, and offering payment to Ayurvedic Physicians and Astrologers (To whom money and/or areca nut placed on top of the sheaf of leaves are offered in thanks for blessings).

• Consumed in Asia as betel quid or paan with arecanut and/or tobacco.

• Used in cooking usually raw for its peppery taste.

• Medicinal use over a 300 years history in China.

7.1. Origin and distribution

• Native to Tropical America, the Amazon Basin.

• Domesticated in Mexico and Central and South America.

• Cultivated in Karnataka, Kerala and Tamil Nadu mainly as intercrop and multi-storey crop with arecanut and coconut from 1970 onwards.

7.2. Economic importance

• Cocoa is a cauliflorus beverage crop.

• Chocolate, hot chocolate, cocoa powder and dry powder are made

• Cocoa butter (the fat) can be extracted.

• Used in Mesoamerican foods including tejate and Mexican drink that also includes maize.

6.1. Origin and distribution

• Native of America and Brazil.

• Introduced in India during later half of the Sixteenth Century.

• In 2017, Vietnam, India, and Ivory Coast were the major producers.

• Cultivated in Andhra Pradesh, Goa, Karnataka, Kerala, Maharashtra, Odisha, Tamil Nadu and West Bengal; also in few pockets of Assam, Chhattisgarh, Gujarat, Meghalaya, Nagaland and Tripura.

• Cashew is called gold mine of waste lands.

6.2. Economic importance

5.1. Origin and distribution

• Indigenous tree of tropical rainforest of Amazon basin of Brazil and introduced in Asia in 1876

• Malaysia, Indonesia, Thailand and Africa are the main rubber producing countries.

5.2. Economic importance

• Natural rubber is available from Manihot glaziovii (Cera rubber), Ficus elastica (India rubber), Castiolla elastica (Panama rubber), Parthenium argenatum (Guayul), Taraxacum koksaghyz and Hevea brasiliensis (Para rubber).

• Hevea brasiliensis is the most important commercial source of natural rubber.

• After proper chemical treatment, rubber wood provides enough strength and durability of any semi-hard wood available in India

• U sed for the manufacture of useful articles like door and window components, furniture, wall paneling, interior decoration, tool handles etc.

4.1. Origin and distribution

• Native to Indian ocean, Malaysia or Philippines

• Grows in tropical Pacific, Asia, and parts of east Africa.

• Areca is derived from a local name from Malabar Coast of India and catechu is from Malay name caccu.

• Karnataka (40%), Kerala (25%), Assam (20%), Tamil Nadu, Meghalaya and West Bengal are major arecanut growing states.

• India is the largest producer and consumer.

3.1. Origin and distribution

• Origin is in South Asia - Malaysia, Pacific.

• In the Pacific, cultivated on islands in Southeast Asia - Philippines, Malaysia, Indonesia.

• In the Indian Ocean, centre of cultivation is southern periphery of India including Sri Lanka, Maldives and Laccadives.

• In India, coconut palms are grown on the entire coastal belt of Kerala, Karnataka and Tamil Nadu followed by Goa, Maharashtra, Andhra Pradesh, and Odisha.

• Kerala, Tamil Nadu, Karnataka and Andhra Pradesh are the major coconut producing states accounting for more than 90% of area and production

2.1. Chromosome number

• Basic chromosome number for the genus Coffea is n=11

• Coffea canephora-diploid (2n=2x=22)

• Coffea arabica (2n=4x=44 )

2.2. Origin and distribution

• Original domesticated coffee plant is said to have been from Harar and native population is derived from Ethiopia (Abyssinia Plateau) with distinct nearby populations in Sudan and Kenya.

• From where, it was taken to Arabia in 11^th century.

• From Arabia, its seeds were brought to India by Baba Budan in the 17^th Century and were raised in the Baba Budan Hills of Karnataka.

• British planters established large coffee estates near Chikmagalur (Karnataka) in 1826, in Manantody (Wynad) and Shevoroys in 1830 and Nilgiris in 1839.

• Almost the entire production is shared by Karnataka, Kerala and Tamil Nadu, smaller production in Andhra Pradesh, north eastern states and Madhya Pradesh.

• Karnataka is the largest producer accounting for 70% of total coffee production and 60% of the area

• Kozhikode, Waynad, Malappuram, Kollam, Kannur and Palakkad are the chief producing districts in Kerala.

1.1. Origin and distribution

• The oldest known beverage, tea is native of China (Between China and Burma) in South East Asia.

• Known to the Chinese as early as 2737BC, but it was a popular drink in England in 1664 AD.

• Original species, which produce tea, were C.assamica (Assam jats), C.sinensis (China jats) and their natural hybrid, C.assamica subspecies lasiocalyx (Indo China or cambod type).

• Chinese (Small leaf) tea - C. sinensis var. sinensis: Originated in southern China possibly with hybridization of unknown wild tea relatives

• Chinese Western Yunnan Assam (Large leaf) tea

• Indian Assam (Large leaf) tea- C. sinensis var. assamica: Originated from Camellia taliensis in the area where southwestern China, Indo-Burma, and Tibet meet

• Chinese Southern Yunnan Assam (Large leaf) tea: Hybridized with the closely related species Camellia taliensis

• Difference between Assam and China types

8.1. Pepper

8.1.1. Phytophthora foot rot / quick wilt: Phytophthora capsici

Symptoms

• Die back

• Discoloration occurs and rotting progress upwards and downwards resulting in die-back.

• Lateral branches of affected vines break off at nodes and fall off.

• Foot rot or collar rot

• Stem near ground level get infected and rotting and death of vine within 2-3 weeks.

• Affected portion emits bad odour.

• Root rot

• Infection starts at main root or at feeder root.

• Leaves become yellow and defoliate.

7.1. Pepper

7.1.1. Pollu beetle: Longitarsus nigripennis

Symptoms

• Grub feeds on growing tip, tender stem, leaf petiole, spikes and berry.

• Tunneling of tender stem causes drying up of shoot.

• Spikes tunneled by grubs turn black and cause dropping of spikes due to rotting.

• Grubs bore into the berries and feed on entire internal contents.

• Exit holes could be seen on dry berries and turn dark - called ’Pollu’ berries.

6.1. Origin and distribution

• The plant originated in the Tarai region of Uttar Pradesh, India, and at present it is cultivated in Burma, Ceylon, China, Australia and the Pacific Islands.

6.2. Economic importance

• Curry leaves are a rich source of vitamin A, vitamin B, vitamin C, vitamin B2, calcium, and iron, apart from a heavy distinctive odor and pungent taste.

• It helps in the treatment of dysentery, diarrhea, diabetes, morning sickness, and nausea by adding curry leaves to your meals.

6.3. Varieties

• Sen Kaampa, Dharwad-1 and Dharwad-2

6.4. Soil and climate

• Red sandy loam soils with good drainage are ideal for better leaf yield.

• Optimum temperature is 26° to 37°C.

5.1. Origin and distribution

• True or black mustard: Brassica nigra Koch-Self sterile

• White mustard (Yellow mustard) : Brassica compestris, Syn: Sinapsis alba- Self sterile

• Indian or brown mustard: Brassica juncea (L.) Czern

• These three species are commonly used as condiment.

• White mustard is indigenous to Southern Europe, whereas brown mustard is from China introduced to Northern India.

• Black mustard is endemic in Southern Mediterranean region.

• White mustard is widely cultivated in Australia, China, Chili, Denmark, Italy, Japan, UK, Netherlands, North Africa, Canada and USA.

4. 1. Origin and distribution

• Native to Egypt, Syria, Middle East and stretching east to India.

• In India, cumin is mainly cultivated in Western Indian states like Rajasthan and Gujarat.

4.2. Economic importance

• Important spice used in Indian kitchens for flavoring various food preparations.

• The flavor is due to chief constituent cuminol (Cuminaldehyde)

• Volatile oil is up to 2.5-3.5 %.

• Used in various ayurvedic medicines especially for the conditions like obesity, stomach pain and dyspesia.

• Many Latino, Vietnamese, United States and Thai foods recipes have cumin and many chilli recipe includes cumin.

• In India, cumin is a traditional ingredient not only curry, but also kormas, masalas, soups and other recipes.

• Used in some cheeses like Leyden cheese as well as some French breads.

3.1. Origin and distribution

• Originated in the Southern Europe, Mediterranean region and grows throughout Northern, Eastern, and Western hemispheres specifically in Asia, Rumania, North America, Europe, India, Russia, Germany and France.

• In India, cultivated in Rajasthan, Andhra Pradesh, Punjab, Madhya Pradesh, Uttar Pradesh, Maharashtra, Gujarat, Karnataka, and Haryana.

3.2. Economic importance

• The leaf stalks are used both as vegetable and salad.

• A common practice in most Indian households is to have few fennel seeds at the end of every meal to freshen the mouth.

• Used for various digestive problems including heartburn, intestinal gas, bloating, loss of appetite and colic in infants.

• Source of copper, potassium, calcium, zinc, manganese, vitamin C, iron, selenium and magnesium.

• The seeds are used as condiment

• Seeds yield 4-5% volatile with anethole as major constituent.

2.1. Origin and distribution

• Native to South Eastern Europe, West Asia and Mediterranean region.

• Cultivated in Central and Southeastern Europe, Western Asia, India, and Northern Africa.

• In India, cultivated in Rajasthan, Madhya Pradesh, Gujarat, Uttar Pradesh, Maharashtra and Punjab.

2.2. Economic importance

• Culinary use in smaller quantities.

• Used as an herb (Dried or fresh leaves), spice (Seeds) and vegetable (Fresh leaves, sprouts, and micro greens).

• Seeds are used both whole and powdered in the preparation of pickles, vegetable dishes, dal and spice mixes such as panch phoron and sambar powder.

• Balance cholesterol.

• Soothe upset stomach and digestive problems.

• Reduce menstrual cramps.

• Seeds are aphrodisiac effect.

• Reduce appetite.

1.1. Origin and distribution

• Native to Southern Europe and Northern Africa to Southwestern Asia.

• Rajasthan, Andhra Pradesh, Tamil Nadu, Odisha, Karnataka and Madhya Pradesh are major producers of coriander in India.

1.2. Economic importance

• All parts of plant are edible, but fresh leaves and dried seeds are used in cooking.

• May help to lower blood sugar.

• Rich in immune boosting antioxidants.

• May benefit heart health.

• May protect brain health.

• May promote digestion and gut health.

12.1. Origin and distribution

• Indigenous to West Indies (Jamaica), Central and South America. Jamaica is the main producer of allspice.

• In India, there are few trees in Maharashtra, Tamil Nadu, Karnataka and Kerala.

• Available in the Mahendragiri hills of Kanniyakumari, and Kallar and Burliar of the Nilgiris of Tamil Nadu; Ambalavayal in Kerala.

12.2. Economic importance

• It combines the odour and flavour of nutmeg, clove, cinnamon and pepper and hence, called all spice.

• Berry, berry oil, oleoresin, leaf oil are the products of economic use.

• Used in food industry (65 to 70%), domestic use (5 to 10%), production of berry oil (20 to 25%), extraction of oleoresin (1 to 2%), and pharmaceutical and perfume industry.

• Has, anti-microbial, insecticidal, nematicidal, anti-oxidant and deodorant properties.

11.1. Origin and distribution

• Native of Atlantic Coast from Mexico to Brazil.

• Vanilla comes from orchids of the genus vanilla.

• Originally came from Mesoamerica, including parts of modern day Mexico and Guatemala.

• Major vanilla producing countries are Java, Mauritius Tahiti, Seychelles, Madagascar, Indonesia, Mexico, Cameroon and Reunion.

• Madagascar and Indonesia produce two thirds of the world’s supply of vanilla.

• In India, vanilla cultivation is gaining importance in Kerala, Karnataka and Tamil Nadu since early 1990s.

11.2. Economic importance

• Second most expensive spice after saffron

10.1. Origin and distribution

• Native of Tropical Africa and cultivated throughout South East Asia, Australia, America and India.

• Cultivated in Tamil Nadu, Maharashtra, Karnataka, Andhra Pradesh, Madhya Pradesh and Odisha.

10.2. Economic importance

• The fruits are used as condiment or as acidulant.

• Fruits that contain a sweet, tangy pulp, which is used in cuisines around the world.

• Used as an acidic/flavouring agent in the Indian cookery.

• High in tartaric acid, sugar, B vitamins, and calcium.

• Used in traditional medicine and as a metal polish.

• Used for woodworking and oil can be extracted from the seeds.

• Seeds are astringent, aphrodisiac useful in giddiness, vertigo.

9.1. Origin and distribution

• Originate from North America, in particular Central Mexico.

9.2. Economic importance

• Paprika contains capsanthin and capsorubin.

• Used to season and color rice, stews, and soups, such as goulash, and in the preparation of sausages, mixed with meats and other spices.

• There are six paprika American, Bulgarian, Hungarian, Moroccan, Spanish and Yugoslavian.

• In US, sprinkled raw on foods as a garnish.

9.3. Types and varieties

• Types of bell pepper

? Green pepper: Can be a little bitter, but it is very useful, such a fruit reduces the level of cholesterol in the blood. And it has the least calories.

? Red pepper: Is the sweetest and contains the most vitamin C.

? Orange pepper: It is also very tasty, but it contains slightly less vitamin C than red.

8.1. Origin and distribution

• Native land is Central Asia, Middle Asia and Northeastern Iran.

• China produces 80% of the world’s supply

• India, Korea, Spain, Egypt, USA, Thailand and other countries are growing garlic.

• In India, cultivated in Gujarat, Haryana, Madhya Pradesh, Odisha, Maharashtra, Uttar Pradesh and Rajasthan

• India exports fresh and chilled garlic, dried garlic, dehydrated garlic flakes, dehydrated garlic powder, and garlic oil to Bahrain, Bangladesh, Germany, Japan.

8.2. Economic importance

• It contains amino acid allicin.

• Used both as a food flavoring and as a traditional medicine

• Allicin, antibacterial substance, the principle of amoebic dysentery.

• The garlic odour is due to diallyl disulfide.

7.1. Origin and distribution

• Originated from Tropical South East Asia.

• Cultivated in India, China, Jamaica, Australia, Mexico, North and West Africa and Taiwan, Fiji, Mauritius, Brazil, Indonesia, Japan, Malaysia, Philippines, Thailand and Bangladesh.

• In India, cultivated in Gujarat, Kerala, Arunachal Pradesh, Odisha, Meghalaya, West Bengal, Tamil Nadu, Andhra Pradesh and Karnataka.

• Karnataka, Odisha, Assam, Meghalaya, Arunachal Pradesh and Gujarat together contribute 65 per cent to the country’s total production.

7.2. Economic importance

• India, China and the Japanese people use ginger as food

• Used as drug in cold, cough, vomiting, dizziness, hypertension, impaired vision problems, digestion, fever and stomach diseases.

• Dry ginger and pepper along long pepper tea helps to remove mucus in the body for a long time and helps to protect health.

.1. Origin and distribution

• Native of South and South East Asia, from there it is spread to Indonesia, China, Sri Lanka, Pakistan and Pacific Islands

6.2. Economic importance

• Used as condiments.

• Rhizomes are boiled in water, dried, ground into a deep orange yellow powder and used as a colouring and flavoring agent in many Asian cuisines, especially for curries, as well as for dyeing.

• Has a warm, bitter, black pepper like flavor and earthy, mustard like aroma.

• Yellow color is due to curcumin (3-9%)

• Anti-inflammatory and antioxidant properties

• Protect against heart disease

• May prevent cancer

• Ease symptoms of osteoarthritis

• Treat or prevent diabetes

• Treating depression

5.1. Origin and distribution

• Native to the Moluccas of Spice Islands of Indonesia.

• In India, cultivated in Thrissur, Ernakulam and Kottayam districts of Kerala, and parts of Kanyakumari and Thenkasi, Nilgiris (Kallar, Buraliar) districts in Tamil Nadu.

5.2. Economic importance

• Fleshy arils surrounding the nutmeg seed are the source of the spice mace.

• Used to flavour many kinds of baked goods, confectionaries, puddings, potatoes, meats, sausages, sauces, vegetables, and beverages such as eggnog.

• Fresh husks are used for making jelly.

• Nutmegs act as stimulant and carminative.

4.1. Origin and distribution

• Originated in the central hills of Sri Lanka and Malabar Coast.

• Distributed in tropical and subtropical regions of North America, Central America, South America, Asia, Oceania

• Cultivated in Sri Lanka, Malagasy Republic and Seychelles.

• In India, it is grown in one or two locations in Kerala

4.2. Economic importance

• Commercial products are

? Quills: Scraped peel of inner bark of mature cinnamon shoots, joined together with overlapping tubes, hollow of which has been filled with smaller pieces of cinnamon peels.

? Quillings: Broken pieces and splits of all grades of cinnamon quills.

3.1. Origin and distribution

• Native to the Moluccas Islands of Indonesia.

• Although Indonesia is the largest producer of cloves, Zanzibar and Madagascar are the major exporters,

• In India, grown in the hilly tracts of Tamil Nadu, Kerala and Karnataka.

3.2. Economic importance

• Clove taste is imparted by eugenol and quantity of pice required is small.

• Pairs well with cinnamon, allspice, vanilla, red wine, basil, onion, citrus peel, star anise, and pepper corns.

2.1. Origin and distribution

• Queen of spices, native to East Indies/ India, originating in the forests of the Western Ghats in Southern India.

• Also grows in Sri Lanka, Guatemala, Indo China and Tanzania.

• Cultivated in Kerala, Karnataka and Tamil Nadu.

2.2. Economic importance

• Used for flavouring various preparations of food, confectionery, beverages and liquors.

• Used as whole pod, seeds or ground.

• Used in garam masala

• Spice mixture seasons meat and vegetable dishes, and masala chai and Turkish coffee.

• Antioxidant and diuretic properties

• May lower blood pressure.

• May contain cancer-fighting compounds.

• May protect from chronic diseases due to anti-inflammatory effects.

• May help with digestive problems including ulcers.

1.1. Origin and distribution

• Originated in Western Ghats and Eastern Himalayas.

• Cultivated in Kerala, Karnataka, Tamil Nadu, Maharashtra, North Eastern States, and Andaman and Nicobar Islands.

• It is the king of spices.

1.2. Economic importance

• Spiciness is due to the chemical compound piperine

• In foods, used as a spice.

• High in antioxidant and anti-inflammatory properties.

• May benefit for brain.

• May improve blood sugar control and lower cholesterol levels.

• May have cancer fighting properties.

Mushrooming population, subsiding agricultural resources; land and water, people’s concern towards quality of vegetable s/food and changing climate throws several challenges for vegetable production. Conventional management and crop improvement strategies alone can no longer sustain the nation’s as well as global demand. So there is an urgent need to adopt modern biotechnological methods which are multidisciplinary where a large number of tools and elements of conventional breeding technique, genetic engineering, molecular biology, molecular genetics, bioinformatics and biochemistry are utilized and integrated. Biotechnological tools provide three major aspects of genetic improvement viz, application of tissue culture, molecular breeding or marker assisted breeding and genetic engineering.

Perennial vegetables live/survive in field for several years and go on yielding vegetables without much care and attention. They are usually planted on the side of kitchen garden without much interference with tillage operations of other annual crops. Tender leaves, shoots, fruits or tubers of a number of perennial crops are used for vegetable purpose in different agro-climatic conditions. They may be trees or shrubs as in bread fruit, jack fruit, drumstick, etc. or bushes as in colocasia or trailing plants as in yams, chow-chow and ivy gourd.

Temperate perennial vegetables are asparagus, rhubarb, artichoke and seakale. All the above crops have tuberous roots, rhizomes or corm. Above-ground portion may dry up during winter and again sprout during spring. Tuber crops like cassava, elephant foot yam, Colocasia (taro), Dioscorea (greater yam, lesser yam) etc. grown under tropical conditions are also perennials. But for cultivation purpose, they are replanted every year and are treated as annuals.

Vegetables which are consumed raw without cooking are known as salad crops. In temperate regions, a large number of quick growing cool season crops like lettuce, celery, parsley, endive, chicory, chervil, cress, water cress etc. are consumed as raw. Only lettuce and celery are cultivated on a commercial scale in developed countries. Growing awareness on nutritional values of raw vegetables and also health consciousness of people resulted in increased consumption of salad vegetables in tropics too. Vegetables like onion, cucumber, tomato, carrot, radish, beet root, cabbage, capsicum, melon etc. are used as salads without cooking. 

(Hindi: Salad) Fam.: Asteraceae (Compositae)

Lettuce is the most popular salad crop of the world and the most important vegetable crop in temperate regions. The crop is grown mainly under protected structures in temperate countries. Tender leaves and heads are chopped and used as salad along with salt and vinegar.

Leaf vegetables are rich sources of provitamin-A, vitamin-C and minerals like calcium, iron etc. They also provide roughage required in human diet. The Indian Council of Medical Research (1984) recommended a daily intake of 100 g and 40 g of leaf vegetables in the diet of woman and man, respectively. Amaranth, beet leaf, spinach, fenugreek, cabbage etc. are the major leaf vegetables grown in the country. In addition, a number of under-utilized annual crops are also grown as leaf vegetables in specific regions. Tender stems and leaves of a number of perennial crops are rich sources of vitamins and minerals and are used for cooking. The major annual leaf vegetables have a few features in common:

1. Most of leaf vegetables are of short duration and the entire harvest is over within 80-90 days
2. Leaf vegetables are cultivated by direct sowing and by transplanting. In direct sowing, seeds are sown as in nursery and harvested 30 days after. In transplanted method, 25-30 days old seedlings are transplanted at a closer spacing and harvesting is done by frequent clippings or cuttings.

Tropical tuber crops are an important group of subsistence crops in tropical and subtropical zones. Carbohydrates synthesised and stored in the form of starch in underground tubers are used as food by millions in under-developed countries. It is also used as raw material by many industries. Cassava, sweet potato, Chinese potato, edible aroids like elephant foot yam, taro, tannia and yams like greater yam, lesser yam and white yam are major tuber crops grown in India.

Tuber crops are mainly grown as rainfed with minimum cost of production. All are propagated through vegetative means and require fertile and well drained loose soil for proper root development. All roots crops require high dose of potassium for high productivity.Cassava is the most important starchy root crop grown in the tropics and is mainly cultivated in southern peninsular India. Introduced during seventeenth century by Portuguese, the crop played a significant role to overcome food shortage among the low income group of people in Kerala. Underground tuber is rich in starch and mainly consumed after cooking. Processed products like chips, sago and vermicelli made of tapioca are also popular in the country. Being easily digestible, it forms an important ingredient in poultry and cattle- feeds. It is also widely used for production of industrial alcohol, starch and glucose.

Potato is fourth major food crop after rice, wheat and maize in the world. It produces the highest dry matter, well balanced protein and more calories/ unit area and time. Unlike other food crops, potato tubers contain vitamin-C (17 mg/100 g). It provides carbohydrates, minerals, fibre and a number of vitamin-B groups. Potato protein is comparable to that of milk and egg. Unlike European countries, in tropics and sub-tropics, the crop is of short duration and fits well in intensive cropping system. It can be grown in a wide range of climatic and soil conditions and tubers are available throughout the year. Tubers can be left un-harvested in the soil for some time and are also suitable for long distance transport and storage. Several products like chips, flakes, French-fries, finger chips, granule, disc, cubes and flour are made out of potato tubers

Origin and distribution

Potato is a native of tropical South America. Traditionally, it was adapted as a commercial food crop in temperate climate under long day conditions, mainly in Europe. It was introduced to India in 16^th or 17^th Century by Portuguese or the British. 

Radish, turnip, carrot and beet root are the major root crops grown in the country. In addition, root crops like rutabaga, parsnip, salsify, chervil and celeriac are grown in a limited scale in different areas. Though the crops belong to different families, their cultural requirements are uniform. The common features of root crops like radish, turnip, carrot and beet root are:

• In all root crops, the tap root and a portion of hypocotyl develop into fleshy root.
• All root crops are cool season crops and are the best grown during winter in plains and spring-summer in hills of North India
• All crops, except beet root, exhibit two distinct groups, viz., tropical or Asiatic or annual types and temperate or European or biennial types. In beet root, tropical annual types are not available.
• Seeds of annual types are produced in plains. Biennial types require a chilling temperature, after attaining or completion of vegetative phase, for transforming to reproductive phase. Since this chilling temperature is available during winter at high altitudes, seed production of biennial types are practiced only in hills of North India.
• All root crops require well drained loose and friable soil without any clods for raising a good crop. Seeds are sown on ridges or on raised beds for proper development of roots.

Bulb crops include onion, garlic, leek, shallot, welsh onion and chive- all belonging to the genus Allium. This genus was earlier included in the family Liliaceae due to its superior ovary. It was later shifted to Amaryllidaceae as flowers are bom in a bracted umbel on top of a scape. Being the typical genus in the family Amaryllidaceae, a new separate family status was given to all the specious under Allium as Alliaceae.

The common features of bulb crops are:

1. The stem is under ground and rudimentary. The edible portion, bulb is formed by fleshy leaf bases in onion, fleshy axillary buds within thin foliage in garlic, blanched stem and leaves in leek etc.
2. All the bulb crops have a characteristic order due to presence of allyl - propyl - disulphide.
3. All are cool season vegetables and are grown during winter months in plains.

Vegetables belonging to the family Brassicaceae (Syn: Cruciferae) are known as Cole crops. These are the most widely grown vegetables in temperate and sub-tropical zones. The word ‘Cole’ comes from abbreviation of word ‘caulis’ meaning stem. Cole crops are a group of highly differentiated plants originated from a wild plant Brassica oleracea var. oleracea (=B. sylvestris L.) commonly known as “Wild cliff cabbage” or “colewort”, through mutation, human selection or adaptation. Cole crops include cabbage, cauliflower, knol khol, Brussels sprouts, Chinese cabbage, sprouting broccoli, kale etc. of which cabbage and cauliflower are the most popular and widely grown.

Mediterranean region is the centre of origin of Cole crops. From there, it spread to Europe and other temperate and sub-tropical regions. Cabbage, knol khol and curly kale were the first known cultivated types. Cauliflower became widely known in the 18^th century and Brussels sprouts in 19^th century. In the thirties of 20^th century, sprouting broccoli started cultivation particularly in the USA.

Linnaeus in 1753 included all forms of Cole crops in one species, Brassica oleracea. Later the works of many, including Neuwhof (1969) resulted in putting them into different forms as given below:

B. oleracea var. capitata L. - Cabbage

Peas and beans belonging to the family Fabaceae (Syn. Leguminosae) are delicious and preferred vegetables grown throughout the world. These include cool season vegetables like pea, French bean, lima bean, broad bean and tropical vegetables like cowpea, hyacinth bean, winged bean, jack bean, sword bean etc. These are integral components of sustainable agriculture due to their ability to fix atmospheric nitrogen and to improve soil properties. Legume vegetables are rich in protein and essential amino acids and have significant role in combating malnutrition among poor people and vegetarians.

Common features of legume vegetables are summarized below:

1. All legume vegetables are self-pollinated due to cleistogamous nature. Flowers are zygomorphic with papilionaceous corolla, mono-adelphous or di-adelphous stamens.
2. All are direct sown crops and do not respond to transplanting. Since seed size is comparatively bigger and they are closely planted, a high seed rate is required for most of crops.

Okra is predominantly a crop of tropics and subtropics. It occupies fifth position, next to tomato, in area under vegetables in the country with a production of 33.24 lakh metric tonnes from an area of 3.47 lakh hectares (2001-02). The crop is cultivated for its young tender fruits, used in curry and soups after cooking. It is a good source of vitamins A and B, proteins and minerals. It is also an excellent source of iodine and is useful for the treatment of goitre. Fruit is useful against genito-urinary disorders, spermetorrhoea and chronic dysentery. Fruits are also dried or frozen for use during off-season. Dried fruit contain 13-22% edible oil and 20-24% protein and is used as refined edible oil. Dry fruit skin and fibres are used in manufacture of paper, card board and fibres. Root and stem are used for clearing cane juice for preparation of jaggary.

Crops belonging to family Cucurbitaceae are generally known as ‘Cucurbits’. It consists of a wide range of vegetables either used for salad purpose (cucumber) or for cooking (all gourds), pickling (West Indian gherkin) or as dessert fruit (muskmelon, water melon) or candied or preserved (ash gourd). As a group, cucurbits occupy the largest area in India and in other tropical countries. Its use is not primarily because of calories, minerals or vitamins since they are generally low to moderate in nutrients with a few exceptions like bitter gourd (rich in vitamin C- 96mg/100g), pumpkin (vitamin A 1600 IU/100g), Kakrol (high protein 3.1g/100g,), parwal and chow chow (calcium- 531 mg and 140 mg / 100 g respectively). From the nutritional point of view, cucurbit seeds are valued for their high oil and protein contents. Seed proteins of cucurbits are comparable to that of legumes and are richer in methionine.

The family Cucurbitaceae comprises about 117 genera and 825 species in warmer parts. Chakravarthy (1982) estimated 36 genera and 100 species in India.

The family Solanaceae consists of 85 genera, which include both tuberiferous and non-tuberiferous ones. Brinjal (Solanum sp.), chilli (Capsicum sp.) and tomato (Lycopersicon sp.) are the major fruit vegetables under the family. In all genera, fruit is an indehiscent berry.

A key for the identification of the above three genera are furnished below:

A. Anthers connivant in a cone, longer than filaments

B. Anthers dehisce by apical pores or short slits, leaves entire, lobed or pinnatifid - Solanum

BB. Anthers dehisce introsely by longitudinal slits, the tips empty, leaves pinnatiset - Lycopersicon

AA. Anthers not connivant in a cone, not larger than the filaments, dehisce by lateral slits - Capsicum

Vegetables are grown on a limited scale in homesteads for family use and cultivated in an extensive scale for marketing. Depending on the purpose for which they are developed, vegetables gardens are classified into different types, viz., kitchen garden or nutrition garden, market garden, truck garden, garden for processing, garden for seed production and vegetable forcing or protected cultivation.

1. Kitchen garden or nutrition garden

Kitchen garden or home garden or nutrition garden is primarily intended for continuous supply of fresh vegetables for family use. A number of vegetables are grown in available land for getting a variety of vegetables. Most of works are done by family members. Area of garden, lay out, crops selected etc. depend on availability and nature of land. In rural area, land will not be a limiting factor and scientifically laid out garden can be established. In urban areas, land is a limiting factor and very often crops are raised in limited available area or in terraces of buildings. Cultivation of crops in pots or in cement bags is also feasible in cities.

The unique advantages of a kitchen garden or home garden are:

(i) Supply fresh fruits and vegetables high in nutritive value

Diverse soil and climatic conditions prevailing in different parts of the country offer scope for cultivation of a variety of crops in India. Around 250 crops either cultivated or grown under natural habitat are used for vegetable purpose. The crops and varieties vary in their soil and climatic requirements, cultivation practices, resistance to pests and diseases, quality etc.

Considering the climatic conditions for growing vegetable crops and for evolving zone wise technologies and recommendations, the entire country is divided into eight agro- climatic zones under the All India Co-ordinated Research Project (Vegetable Crops) as given below:

Table: Agro-climatic zones and states under each zone

Quite a large number of vegetable crops are grown in the country either on a commercial scale or limited to backyards of homesteads. A few crops have similarity while others have dissimilarity in their climatic and soil requirements, parts used, method of cultivation etc. While describing individual vegetables, there is possibility of repetition in many aspects. In order to avoid repetition, it is essential to classify or group them into different classes/groups. Different methods of classification followed in vegetables are described below:

I. Botanical classification

Botanical classification is based on taxonomical relationship among different vegetables. Plant kingdom is divided into four viz. Thallophyta, Bryophyta, Pteridophyta and Spermatophyta. All vegetables belong to Division Angiospermae of Spermatophyta. It is further divided and two classes viz., Monocotylydoneae and Dicotylydoneae.

Vegetables are defined as edible herbaceous plants or parts of plants consumed as raw or after cooking and are rich in vitamins and minerals, low in calorific value and neutralize the acid substances produced during digestion of high energy foods. Olericulture is a branch of horticulture that deals with production, storage, processing and marketing of vegetables and has its origin when man started growing vegetables for human consumption. The term Olericulture comes from Latin words holus-holeris = any kind of culinary vegetable, pot herb, and cultura = to cultivate.

Vegetable crops include a large number of plants, mostly annuals and a few perennials, grown for their edible leaves, stem, flower buds, flowers, fruits and roots. Vegetables are integral part of a balanced diet and are considered as “Protective foods” as their consumption prevent several diseases. They have a prominent role in combating malnutrition of animals and human beings.