Taxonomy, Cultivation and Other Practices of Haridra

 

1.   Taxonomy

 

Curcuma longa Linn.

 

Zingiberaceae

 

2.   Distribution

 

·     A genus of about 70 species of rhizomatous herbs distributed in India, Siam, Malay Archipelago and N. Australia. About 30 species occur in India of which a few are of economic importance.

 

·     A genus of rhizomatous herbs distributed mainly in the Indo Malaysian region. About 18 species occur in India of which a few are important spice plants including the Turmeric and Zedoary.

 

·     The plant is a native of Southern Asia (probably India) and is cultivated extensively throughout the warmer parts of the world. It is grown on a large scale in India, China and East Indies. It is cultivated in almost all the States in India, particularly in Madras, Bengal and Bombay. . The main regions of cultivation in Madras are Guntur, Cuddapah, Krishna, Kerala . In Maharashtra , the chief area of cultivation being Satara district.

 

·     There are several varieties of turmeric distinguished by the names of localities in which they are grown. References are found to two cultivated varieties in the reports of various States, but as differential local names are applied it is difficult to say whether the same two varieties are meant in every case. Two varieties are cultivated in  Maharashtra one giving a hard and bright coloured rhizome, and the other, a somewhat softer, larger and a lighter coloured rhizome. The former is more commonly employed in dyeing and the latter as a condiment (Ambekar, Bull. Dept. Agric., Bombay,No.146, 1927, 85). The two varieties cultivated in Assam and Bengal are Deshi and Patani (Patni in Bengal), the latter having a better colour and flavour (Leafl. Dep. Agric., Assam,No.17, 1939). China nadan and Perum nadan are grown in Bhavani and Erode Talukas of Tamil Nadu State, the former being more extensively cultivated because it grows more vigorously and its rhizome has a sweeter aroma (Rajaratnam, Madras agric. J.,1923, 11, 42). Turmeric cultivated in the hills is reported to be a better quality than that raised in the plains. It is stated that the same variety when grown in the plains and on the hills shows distinct differences in quality and yield (Narasimham, Madras agric. J.,1931, 19, 256). Chennai turmeric is highly esteemed in the market.

 

3.   Description

·     A perennial herb, 2-3 ft. high with a short stem and tuffted leaves; the rhizomes, which are short and thick, constitute the turmeric of commerce. Turmeric is used both as a colouring material and as a condiment. The characteristic yellow matter, distributed throughout the plant, is especially concentrated in the rhizomes.

 

4.   Cultivation

 

 

·     In rare cases, however, as many as a dozen roots may form tubers in a single plant. The tubers are of varied shapes and sizes, the common ones being almond-shaped, 1-6cm x 0.5-2.5cm; and are rich in starch. The production of these tubers was found to be conditioned by varietal differences, soil factors and agronomic practices. Also it was found that when finger rhizomes were used as seed material, there was a significantly higher production of root tubers. Although histologically these tubers are not pathological, their formation has an adverse effect on the yield of rhizomes (Reddy & Sarma, Andhra Agric J, 1957, 4, 96; Sarma & Ramesam, ibid, 1958, 5, 216).

 

·     The crop requires a hot and moist climate, a liberal water supply and a well-drained soil. It thrives on any soil-loamy or alluvial-but the soil should be loose and friable. Gravelly clayey and stony soils are unsuitable for the development of rhizomes. In tracts of heavy rainfall, as in the west coast, it is grown as a rainfed crop. In other areas, it is cultivated under flow or filt irrigation. Turmeric can be successfully grown in paddy fields on raised beds beyond the reach of stagnant water. It is usually rotated with Eleusine coracana Gaertn. (ragi), Oryza sativa Linn. (paddy), Saacharum officinarum Linn (sugarcane) and other crops. It is rarely cultivated as a pure crop; it is usually grown mixed with castor, maize, ragi, onions, brinjal, tomato, etc. Short duration catch crops like French beans (Phaseolus vulgarisLinn.) are sometimes raised in turmeric fields in Ceylon (Paul & Fernado, Trop. Agriculturist,1941, 97, 10).

 

·     The field should be well prepared by ploughing and turning over to a depth of about one foot and liberally manured with farm yard and green manures. Sometimes tank silt is applied or cattle and sheep penned on the fields. Potash and organic manures are beneficial (Rao, Madras Agric. J.,1949, 36, 323; Nair, Allahabad Fmr,1946, 20, 146). After the manure is spread and the field is ploughed 3-4 times till a good tilth is obtained, ridges are made, 9-10 in. high and 18-20 in. broad with channels between rows for irrigation. Sets or fingers of the previous crop with 1 or 2 buds are planted 3 in. deep at distance of 12-15 inches in April-August at the rate of 1,500-1,800 lb. per acre (Narasimham, loc. cit.; Lakshmanan, Madras Agric. J.,1949, 36, 267). Field experiments in Sri Lanka have shown that plants spaced 6 in. x 6 in. yield significantly more of rhizomes than plants spaced 12 in. x 12 in. or more. The plants drive well in partially shaded areas, but shade adversely affects the yield (Paul & Fernando, Trop. Agriculturist, 1944, 100, 9). Weeding and hoeing are necessary at intervals. The crop is ready for harvesting in about 9-10 months when the lower leaves turn yellow. The rhizomes are carefully dug up with hand picks. The yield is very variable, ranging from 12,000 to 22,000 lb. of green or raw tumeric per acre, but yields as high as 25,000 lb. per acre have been recorded (Madras Agric. J.,1937, 25, 25.).

 

·     Curing and preparation for the market: The rhizomes, which are brownish yellow in colour, consist of a central bulbous portion bearing a number of finger-like lateral offshoots. The bulbous and finer-shaped parts are separated, and the long fingers which generally command a high price in the market, are broken into convenient bits. They are freed from adhering dirt and fibrous roots and subjected to a process of curing and polishing. The curing consists in cooking and rhizomes in water until they become soft. A few leaves of turmeric are usually added to the water in the cooking vessel. Addition of a little cowdung is said to intensify the colour of the product. The cooking should be thorough as otherwise, the product is liable to insect attack. The duration of cooking varies in different localities from about 30 min. to 6 hrs. (Ramanna, Mysore Agric. J.,1935, 15, 136). The cooked rhizomes are allowed to cool gradually, and spread out in the open to dry with intermittent turning over to ensure uniformity in drying. The dried rhizomes are either rubbed on a rough surface or are trampled upon to remove the outer skin and to give them an attractive colour and polish.

 

·     Various improvements in the cooking vessels and heating furnaces, and in the method of polishing the product, have been suggested. The Sindwahe furnace used in Kurnool distict for making jaggery has been employed for cooking the rhizomes, using dried leaves of turmeric as fuel (Madras Agric. J.,1938, 26, 444). A polishing drum (2 ft. long x 3 ft. diam.), of expanded metal, horizontally mounted and rotated by a handle at 30 r.p.m. has been designed by the Madras Agricultural Department. The expanded metal is covered on the outside with a light wrapping of woven wire to prevent the small pieces from falling through. It can take in a charge of 70 lb. of turmeric, and the polishing is complete in 7 minutes (Madras Agric. J.,1938, 26, 79). Sprinkling of water during the polishing is said to improve the colour (Karunaratne, Trop. Agriculturist, 1937, 89, 350). The yellow dust obtained during polishing is used as manure for paddy fields.

 

The outturn of the dried product varies with the quality and ripeness of the raw tubers and ranges from 17 to 25% of the fresh material (Yegna Narayan Aiyer, 285). Cured and finished turmeric is brittle; it has a shining yellow colour on which its market value depends In some areas a special treatment is given to improve the appearance of the product. This consists in soaking the material for 10 min. in an aqueous extract of tamarind to which has been added a paste of turmeric. In Mysore, The poorly developed red branches of the rhizomes of one variety are separated, cut into pieces and utilized, without curing, for preparing Kumkum.

 

·     Area And Production : Turmeric is one of the five major spices of India and ranks high in its export earnings, being next only to black pepper and cardamom. It is cultivated throughout the length and breadth of the country. The area and production of turmeric has gone up and down in different years. As per official statistics, c 3.5 lakh tonnes of turmeric were produced from an area of c 1.17 lakh hectare in 1991-92. India has a prime position in the world production of turmeric. It is estimated that 80 per cent of the world production is coming from India, although nearly 95% is consumed within the country. About 18 states in India cultivate turmeric. However, turmeric cultivation is largely confined to South and Eastern India. It is grown as a rainfed and irrigated crop in fourteen states of the country. Of these, Andhra Pradesh, Tamil Nadu, Orissa, Karnataka and West Bengal contributed c 90% of the production. As an irrigated crop it is grown in Andhra Pradesh and Tamil Nadu. It is grown on a large scale in Andhra Pradesh ( accounting for c 42% of the production) and in Tamil Nadu (c 11%) ; Orissa, Karnataka, West Bengal, Maharashtra, Bihar, Kerala and Assam are the other states growing the crop. It is grown to a small extent in the lower and mid- hills altitudes in Meghalaya and Himachal Pradesh.

 

·     In Andhra Pradesh, turmeric is cultivated mainly in five regions, viz. Nizamabad, Karimnagar, Guntur, Cuddapah an Adilabad districts with Nizamabad contributing to nearly 20% of the state produce. In 1991-92, Andhra Pradesh was the largest producer of turmeric followed by Orissa (George, Indian Spices, 1993,30 (2-3), 22; Venkataraman in Nair et al, 5; George & Velappan in Nair et al, 207; Randhawa, et al, J Res, Ludhiana, 1973, 10, 45; Sriramarao, in Nair et al, 213).

 

·     Breeding And Varieties  : One of the most important problems facing the turmeric crop is its duration of 7 to 9 months. Therefore, the main objectives of breeding work on turmeric are (1) evolving short duration varieties; (2) breeding soft-rot resitant varieties; (3) breeding varieties with high yield, high oil and curcumin content; (4) to overcome the reasons for sterility; and (5) to collect wild forms for breeding work.

 

·     An All-India survey conducted by Central Plantation Crops Research Institute (CPCRI) Kasaragod, Kerala in collaboration with National Bureau of Plant Genetic Resources (NBPGR), New Delhi and Himachal Pradesh Agriculture University has enabled to collect c 120 accessions of turmeric. They are being multiplied and preliminary studies have revealed that there is a wide variability for quality and yield characters. Hybridization with C. aromatica should be carried out to obtain types possessing high yield, and high curcumin and oil contents (Venkataraman in Nair et al, 5; Nair et al, 15).

 

·     Genetic variability and correlation studies were conducted on ten genotypes of turmeric to assess the genetic parameters and degree of mutual association in respect of yield and yield determining characters. The characters such as  yield of cured turmeric, number of primary fingers and yield of secondary fingers showed a good amount of variability, high magnitude of heritability and appreciable expected genetic advance. The yield of cured turmeric was found to be significantly correlated with yield of secondary fingers. The significant relations of quantitative characters and with those of primary fingers of secondary fingers with each other suggested the scope for obtaining a good response to selection through direct as well as indirect selection. In another study on 14 cultivars of turmeric, highly significant differences among the genotypes, for characters like yield/plant, fingers/plant and weight of single finger, were observed. Yield/plant and finger/plant had high genotypic coefficient variation coupled with high value of genetic advance and moderately high heritabilities. It indicates that selection may effectively be based on these characters and then phenotypic expression would be a good indicator of genotypic potentiality (Jalgaokar et al, Indian Cocoa, Arecanut Spices J, 1990-91, 14, 20; Nandi, Indian J Agric Sci, 1991, 61, 941).

 

·     Eight turmeric varieties belonging to C. longa and C. aromatica were crossed. Seed setting was observed in eight of the eleven crosses tried and in the variety `Nandyal' by open pollination. The germination of these seeds were ranged from c. 17 to 100% per cent and the seedlings only produced tubers during the first year of growth (Nazeem & Menon, S Indian Hort, 1994, 42, 161).

 

·     For multiplication of promising clones and for breeding resistance to major diseases, tissue culture technique was tried on clone `15B'. As many as 25 shoots per explant were obtained at a rate much faster than normal seed propagation (Shetty et al, in Nair et al 39).

 

·     Climate & Soil : Turmeric is grown generally as an annual crop. It requires a warm and humid climate. It is cultivable from sea- level up to 1200 m. Turmeric thrives in well-drained, fertile, sandy and clayey, black red or alluvial loams, rich in humus and uniform in texture and easily workable. It cannot stand water-stagnation or alkalinity. On heavy soils, it can be grown on raised beds [Venkateswaran, 207; Handbook of Agriculture, 1980, 1184; Nair, in Nair et al, 63; Adhate, Farmer, 1958, 9 (12), 21].

 

·     Preparation of land:- The land is deeply dug or ploughed 4-6 times to bring the soil to a fine tilth. With the last ploughing, manure is incorporated. Where the soil is porous, it is divided into beds of 1-2m width and convenient length with a spacing of 30cm between the beds for drainage channels. In case of the irrigated crop and where the soil is non-porous, ridges and furrows are prepared and the rhizomes are planted in pits on shallow beds on the tops of ridges or on both the sides of the ridges. Mulching the bed with green leaves is an important practice beneficial to the crop when planting is done on raised beds. Two or three mulchings are given, the first immediately after planting and the second and third at intervals of 40-50 days (Handbook of Agriculture, 1980, 1185; Venkateswaran, 207).

 

·     Seeds and Sowings: Turmeric can be propagated through seeds and rhizomes, but it is generally done through rhizomes as using seeds is not economical in commercial cultivation. Mother rhizomes as well as fingers are used as planting materials. Studies conducted to determine the most suitable planting material have revealed that generally mother rhizome is the most suitable planting material. However, in case of var. `Tekurpeta' transplanting of 30 day old sprouts were equally productive. In case of vareity - `Lakadong', half mother rhizome (18-20 g) showed remarkable tolerance against Taphrina leaf spot disease, although the yield was low as compared to full mother rhizome. In another trial, however, half mother rhizomes (35-44g), were found the best planting material in terms of fresh rhizome yield, cured produce yield and curcumin content. The mother rhizome is cut into two, each having at least one sound bud; fingers cut into 4-5cm long pieces can also be used as planting material [Nair in Nair et al, 65; Nair et al, 62; Govind & Gupta, New Bot, 1989, 16 (1-4), 65; Umrani et al in Nair et al, 79; Singh & Kar, Indian Cocoa, Arecanut Spices J, 1991, 14, 153; Philip, ibid, 1983, 7, 8; Handbook of Agric, 1980, 1185].

 

·     Soaking of rhizomes, of cultivar `Co 1' and `BSR 1' , in 0.2 per cent potassium nitrate recorded early germination, enhanced sprouting percentage and seedling vigour. Finger rhizomes were found early sprouting than mother rhizome (Balashanmugam & Vanangamudi, Madras Agric J, 1992, 79, 209; Balashanmugam et al, S Indian Hort, 1993, 41, 152).

 

·     The conventional method of propagation has a number of drawbacks, viz. c. 2 months dormancy period of rhizomes, only 5-6 plants can be obtained from each rhizome; and a sizeable percentage of the produce has to be put aside as seed material. To overcome these problems tissue culture technique was tried for propagation of some high yielding cultivars - `Duggirala', `Tekurpeta', `BSR-1', and `Co. 1', giving high success percentagee (Nadgauda et al, Indian J Exp Biol, 1978, 16, 120; Keshavachandran & Khader, S Indian Hort, 1989, 37, 101).

 

·     The time of planting of turmeric varies with the cultivar as well as the agroclimatic condition of the area. The turmeric is generally planted between mid-April and August. The short-duration varieties are planted in the second fortnight of May, the medium duration ones in the first-fortnight of June and the long durations between 15th June and 15th July. Besides, when fingers are used as seed, planting should be done by first-fortnight of July; but with cut mother rhizomes, planting as late as first week of August does not affect the yield. Studies conducted at Tamil Nadu revealed that turmeric planted at 1st June gave highest yield of 40,000 kg/ha. In general yield decreased with late planting. However, in Rewa, Madhya Pradesh, planting on 16th May gave best yield from the mother rhizome [Nair in Nair et al, 65; Umrani et al in Nair et al, 79; Handbook of Agriculture, 1980, 1185; Sarma & Murthi, Andhra Agric J, 1965, 12 (3), 84; Balashanmugam et al, Indian Cocoa, Arecanut Spices J, 1989, 12, 124; Barholi et al, Gujrat Agric Univ Res J, 1992, 17, 172].

 

·     The optimum spacing for sowing turmeric is 30-35cm x 20cm for beds and 45-60cm x 25-30cm for ridges and furrows. Rich black loam soils require wider spacing than light soils. A seed rate of 2000-2500 kg/ha may be adopted depending on the spacing given. In mixed cropping the seed-rate is much less; in fruit gardens it may be as low as 400-500 kg/ha. The seed material is dipped in Aggalol (0.3%) soln for 30 minutes and then air-dried. The treated material is dibbled behind country ploughs and then covered [Rao, Indian Spices, 1975, 12 (2), 2; Rajput et al in Nair et al, 83; Ramachandran & Muthuswami, S. Indian Hort, 1984, 32, 143; Handbook of Agriculture, 1980, 1185; Nair et al, 62; Venkateswaran, 208).

 

·     Manures & Fertilizers: Turmeric needs heavy manuring; light soils are more heavily manured than heavy soils. Usually 40-50 tonnes of Farm Yard Manure (FYM) is applied as a basal dressing. About 1200-1800 kg of groundnut cake is applied in 2 split doses, the first after planting and the remaining a month and half later. Alternatively NPK fertilizers at 30:30:60 kg/ha may be applied in split doses of 30 and 60 days after planting. Tank silt or cattle or sheep penving is also done to supply the bulky organic manure. In Tamil Nadu, higher rate of NPK 187.5:62.5:125 k/ha after a basal dressing of 25kg of FYM gave the best results with respect to growth, yield and quality of turmeric. However, studies have shown that K at 90 kg K2O/ha in four splits (basal, 60, 90 and 120 day after planting) recorded the highest yield. Application of 90 kg N and 60 kg P2O5 /ha was found optimal for turmeric var Co.1 in Tamil Nadu. In Orissa, in addition to 10-15 tonnes/ha FYM, a fertilizer dose of 90:60:60 kg/ha of NPK was found remunerative. In Simla hills, due to scarcity of FYM in the hilly regions, a fertilizer requirement of 150:50:50 kg/ha NPK proved to be the best and significantly increased the yield of the crop. After every manuring operation, the plants are earthed up. It was observed in a study on nutrient removal by turmeric, that in Kerala condition, the crop was mainly potassium and nitrogen-exhausting, while it removed Mg and P to only a small extent.However,application of 160 kg N/ha gave the maximum yield of fresh rhizome with variety `Sugandham'under terrace cultivation in Mizoram conditions [Venkateswaran, 208; Handbook of Agriculture, 1185; Rao, Indian Spices, 1975, 12 (2), 2; Nair et al, 62; Purseglove et al, II, 539; Hort Abstr, 1986, 56, 4478, 4479; Balashanmugam & Subramanian, S Indian Hort, 1991, 39, 139; Muthuvel et al, ibid, 1989, 37, 61; Sahu & Mitra, Fertil News, 1992, 37 (10), 59; Randhawa et al, J Res, Ludhiana, 1973, 10, 45; Pandey, Indian Cocoa, Arecanut Spices J, 1992, 16 (1), 14; Nagarajan & Pillai, Madras Agric J, 1979, 66, 56].

 

·     Irrigation: In heavy rainfall tracts of the West Coast, turmeric is grown as a rain-fed crop and in other areas as an irrigated crop. During summer, irrigation at 5 day intervals is recommended in case of red loam and at 7-9 days in the case of black loams. However, in clayey soils, 15-20 irrigations and in sandy soils c. 40 irrigations are required. During the period of rhizome development and maturity, frequent irrigations are necessary. In a study to determine water- production function for turmeric in Andhra Pradesh, it was concluded that 2.0 ha-m water is needed for potential rhizome production and 1.9919 ha-m for maximum net returns under the prevailing prices of water and rhizome yield [Nair et al, 62; Handbook of Agriculture, 1980, 1184; Rao, Indian Spices, 1975, 12 (2), 2; Rao et al, Indian J Agric Sci, 1992, 62, 405].

 

·     Interculture: Mulching is found to be essential for turmeric as it checks weed growth, enhancs the germination percentage and also conserves soil moisture for the crop. Experiments conducted at Pottangi, Orissa with different mulch materials have shown that highest return per rupee (Rs 2.16) was relised by first mulching with dry forest leaves at planting and sowing french bean as intercrop at 45 days of planting instead of 2nd and 3rd mulches. Mulching with dhaincha (Sesbania aculeata Pers.) and sunnhemp (Crotalaria juncea L.) was found to be the best for turmeric crop. It may be done twice. Three to four hoeings, the first one month after planting, followed by weeding are the recommended interculture practices. In all two weeding in a cropping season may be practiced or alternatively application of herbicide plus one hand weeding is recommended to control the growth of weeds such as grasses and some broad-leaf plants. Fluchloralin (Basalin) (2,000 ml/ha) is recommended and if soil is very cleyey, the dose can be increased by 1000 ml. The ideal thing to do is spray the chemical immediately after planting the rhizomes, followed by irrigation (Mohanty et al, Indian Cocoa, Arecanut Spices J, 1991, 14 (3), 97; 1991, 15 (1), 8; Venkateswaran, 208; Nair et al, 62; Hort Abstr, 1986, 56, 2726; Frms' J, 1989, 9 (1), 55).

 

·     Germination and growth:  Germination is generally completed in 2-4 weeks. For breaking dormancy of seed material, seeds are soaked in 50% sulphuric acid for 10min. and then thoroughly washed daily for 15-17 days. As a result, 90% germination was achieved. Flowering occurs after c. 5 months and rhizomes are then begining to form. Active rhizome development continues till the crop is ready for lifting in~7-9 months, when the lower leaves turn yellow (Purseglove et al, II, 539; Curr Sci, 1954, 23, 207).

 

·     Rotations and mixtures: Turmeric can be grown as an intercrop with many other crops because it comes up well in partial shade conditions, although thick shade affects the yield adversely. Therefore, it is recomended as an intercrop in coconut and arecanut gardens. It can also be gorwn as a mixed crop with arhar or sunhemp, chillies, colocasias, onion, brinjal and cerelas like - maize and ragi. In Deecan, turmeric is grown with many vegetables but not as a proper mixture. Turmeric, french beans and fodder maize are popular mixtures. French beans are planted on the crest of the ridge and maize in the furrows, and turmeric in the middle height of the ridge. This allows the farmer to reap the materials, vegetable or fodder in 2-2½ months, particularly when there is scarcity of both. The nutritional and space requirement of turmeric are very little in the begining and later only turmeric is left to grow in the field. Studies conducted in Tamil Nadu has revealed that turmeric grown on broad flattened ridges in two rows with two rows with two rows of onion as intercrop gave the maximum rhizome yield (c 36,500 kg/ha). The economics of double intercroping was studies at Coimbatore and it was found that turmeric as the main crop followed by fenugreek as the first intercrop and onion as the second intercrop gave the best results, followed by turmeric + beans + beetroot [Nair et al, 62; Satheesan & Ramadasan, in Nair et al, 69; Adhate, Farmer, 1958, 9 (12), 21; Balashanmugam & Vedamuthu, S Indian Hort, 1989, 37, 189; Hort Abstr, 1986, 56, 4477].

 

·     In Wynaad, turmeric is grown as an intercrop in coffee plantations, particularly in its early years of growth. In West Bengal, it is grown with mango, jack-fruit and litchi. In the Kurseong Forest Division of West Bengal, trials with turmeric as an intercrop proved successful, giving additional income as well as growth improvement of the forest crops in the interplanted area. In Madras, turmeric is interplanted in teak planatation. In an intercropping system of mulbery, turmeric and pea, the leaf yield of mulbery increased by 16.93% alongwith 10.98% improvement in rhizome yield. The value of land-equivalent ratio (4.21) indicated advanatge in yield and raises the possibility of increasing profits up to 2.69 times by intercropping without hampering the leaf yield of mulbery [Nair, Indian Coffee, 1991, 55 (8), 9; Lahiri, Indian For, 1972, 98, 109; Venkataramany, ibid, 1956, 82, 225; Kumar et al, Indian Farming, 1993, 43 (2), 22; Tikader et al, Indian J Agric Sci, 1992, 62, 523].

 

·     Rotation of turmeric with vegetables and cereals is also practiced in many places. In wetlands, turmeric is rotated with paddy, sugarcane, banana, etc once in 3-4 years. In garden lands, it is gorwn in rotation with chilli, sugarcane, onion, garlic, yam, elephant's foot, other vegetables, pulses, ragi or maize. In Gujarat, it is cultivated as a crop subsidiary to ginger and in other areas with chilli and quick-growing vegetables. Often castor and pigeon pea are planted on borders to provide shade to the turmeric crop (Handbook of Agriculture, 1980, 1184-1185; Venkateswaran, 207).

 

·     Turmeric genotypes PCT-13 and 14 produced significantly higher average fresh rhizomes yields and cured yields than all other cultures. PCT-8 (Suvarna) recorded high curcumin content and high curing percentage. The rhizomes of all the short duration cultures were found to be free from rhizome rot disease. Among all the short duration cultures studied, the genotypes PCT-13 and 14 were found to be suitable for cultivation in Northern Telangana zone. (Reddy, M.L.N., Andhra Agricultural Journal, 45(3&4), 144, 1998)

 

      In a laboratory experiment dry rhizomes of 23 turmeric cultivars were subjected to abrasion with ten abrasive tools. The colour of these abrasions was compared with standard colour chart. The colours developed during curcumin analysis by ASTA method were extrapolated with colour chart. Based upon these comparisons the curcumin content in percent was fixed. Farmers were given macrophoto print of these colours with corresponding curcumin contents. Among the abrasive material, cloth based fine grade emery paper proved to be the best followed by medium and coarse paper. Farmers can make abrasions on processed dry rhizomes with these emery papers and directly read the curcumin content by reference to the colour chart. (Balashanmugam, P.V, Golden Jubilee National Symposium on Spices, Medicinal and Aromatic  Plants Biodiversity, Conservation and Utilisation, Calicut,  India,  12, 10).

 

      Distribution, production and economics, uses, climate and land requirement, varieties, cultivation methods and time, diseases and pests, storage and curing of Curcuma longa have been described. (Upadhyay, D.C., Spices India, 9(5), 12, 1996).

 

      Climate, soil and manure required for the cultivation of turmeric (Curcuma longa), its improved varieties, mulch­ing, insects and pests, production and curing have been described. (Dhote, D.N. Spice India,  11(5),).

 

5.   Diseases & Pests

 

·     Turmeric suffers from foliar and rhizome diseases. Among the foliar diseases, the most common are the leaf blotch and the leaf spots.

 

·     The leaf blotch of turmeric caused by Taphrina maculans Butler is commonly prevalent in the country. It is characterized by the appearance of several brownish yellow spots on both the surfaces of leaves. The leaves get distorted and become yellow very soon. The foliar destruction due to excessive spotting may cause heavy reduction in yield. It can be controlled by the use of fungicides like Bordeaux mixture, aureofungin, zineb, dithane, etc. Some of the cultivars are resistant (Joshi & Sharma, in Nair et al, 104, Handbook of Agriculture, 1980, 415).

 

·     Leaf spot or anthracnose, caused by Colletotrichum capsici (Syd.) Butler & Bisby is reported to be severe in Tamil Nadu and Andhra Pradesh. Severely affected crop gives significantly low yields. The disease can effectively checked by spraying Bordeaux mixture and selecting disease - free seed material. In Andhra Pradesh, four sprayings with Flit 406 or dithane at monthly intervals from September to December were found adequate for checking the infection, besides giving higher yields. Varieties `China' and Jaweli' were found to be resistant to this disease. Varietal evaluation against the disease under hill conditions has shown that out of 6 varieties screened, TC3 (PTS-38) was found less susceptible (Joshi & Sharma, in Nair et al, 104; Handbook of Agricture, 1980, 415; Nair & Ramakrishnan, Curr Sci, 1973, 42, 549; Dakshinamurti et al, Andhra Agric J, 1966, 13, 69; Kandaswamy, Madras Agric J, 1958, 45, 55; Upadhyay & Pavgi, Indian Phytopath, 1967, 20, 29; Prakasam et al, S Indian Hort, 1991, 39, 166).

 

·     Another leaf spot caused by Phaeodactylium alpinae (Sawada) M.B. Ellis has been reported from Sikkim causing extensive damage to turmeric crop (Shrivastava & Verma, Curr Sci, 1987, 56, 673).

 

·     Other foliar diseases include leaf blight caused by Corticium sasakii (. Matsumoto) reported from Assam, and leaf spot by Phyllosticta zingiberi  ( Saikia & Roy, Indian Phytopath, 1975, 28, 519; Summanwar & Bhide, J Indian Bot Soc, 1961, 41, 313).

 

·     Rhizome diseases mainly include rhizome rot and storage rot of turmeric. Rhizome rot caused by Pythium graminicolum ( L.S. Subram.) has been recorded from Andhra Pradesh and Tamil Nadu and that by P. myriotylum Drechsl. from Assam. The infected plants first show progressive drying up of leaves, then spots on aerial shoots and then the roots and rhizomes become discoloured and soft and begin to rot. In cases of severe infection, the yield is considerably reduced. Addition of urea (1%) to the soil checks the fungus. Complete eradication of infected plants is also an effective control measure. Raising the level of the beds, sowing disease-free seed, spraying Bordeaux mixture or using a rhizome dip in Ridomil are other control measures. Detailed studies on rhizome rot conducted in Nizamabad District, Andhra Pradesh revealed the complex nature of the disease. Pythium sp., Fusarium sp. and fly maggot were found associated with the complex. Based on the studies, following practices were suggested to minimise the disease occurrence: 1) discourage the cultivation of highly susceptible varieties like `Armoor' in disease prone areas; 2) maize as an intercrop be sown separately in rows after every 2 rows of the turmeric; 3) adopt spacing of 30x15 cm for turmeric and 60x30 cm for maize; 4) use healthy rhizome seeds; 5) provide adequate draniage; 6) on the appearence of disease symptoms, spray fungicide carbendazim and drench the soil with Bordeaux mixture (1%) (Joshi & Sharma in Nair et al, 104; Rathaiah, Indian Phytopath, 1982, 35, 415, 297; Handbook of Agriculture, 1980, 415; Shankariah et al, Indian Cocoa, Arecanut Spices J, 1991, 14, 104).

 

·     Storage disease of rhizome caused by Sclerotium rolfsii Sacc. is rampant in Guntur district of Andhra Pradesh, affecting the heart of the mother rhizome. It results in low germination, poor vigour and low yield of turmeric. Treating the seed rhizomes with Ceresan Wet soon after harvest, reduces the incidence of disease (Saikia & Roy, Indian Phytopath, 1975, 28, 519; Reddy & Rao, ibid, 1973, 26, 24).

 

·     Rhizomes stored for seed purposes were found infected by several fungi including species of Aspergillus, Fusarium, Cladosporium, Fusarium, Macrophomina, Pythium, Rhizoctonia, Sclerotium, etc. Such storage rot, particularly that caused by A..flavus Link can be successfully prevented and controlled by pre- and post-inoculation treatment with bavistin and benomyl [Sharma & Roy, Curr Sci, 1984, 53, 869; Kumar & Roy, Indian J Agric Sci, 1990, 60, 189; Sharma & Roy, Pesticides, 1984, 18 (11), 26].

 

·     Brown rot of rhizomes caused by Pratylenchus and Fusarium complex has also been reported (Joshi & Sharma in Nair et al, 104).

 

·     Of the insect pests of turmeric, the shoot borer or tissue borer - Dichocrocis puncteferalis Guenno is reported to cause the maximum damage producing `dead heart' symptoms. It bores into the central shoot, as a result of which the plant dries up. Removal and destruction of the affected shoots, and destruction of larvae at the initial stages of infection help to contain the pest. Spraying with 0.04% endosulfan or 0.1% carboryl also check the attack (Nair in Nair et al, 101; Handbook of Agriculture, 1980, 542).

 

·     Many sucking insects and defoliators have been recorded on turmeric. The hard scale, Aspidiotus hartii Cockerell and A. curcumae Gr. infests fresh rhizome and sucks the sap resulting in desiccation of the stored turmeric. Selecting healthy seeds for planting or drenching with 0.95% Lindane emulsion are used to control the pest. Another pest infecting the fresh rhizomes is the rhizome fly, Calobata albimana Macq reported from Andhra Pradesh. The tinged bug or the lace wing bug, Stephanitis typicus Distant infests the leaves in colonies, sucking their sap and causing their discolouration giving a sickly appearence to the plant. Dusting with 5% BHC or 0.1% malathion is done for control. The thrips, Panchaetothrips indicus Bagnall attacks the leaves which roll up, turn pale and gradually dry up. Stegobium paniceum has ben reported as a pest of stored turmeric from Rajasthan. Fumigation with a mixture of ethylene dibromide (EDB) and carbon tetrachloride proved the most suitable control measure. Cigarette bettle, Lasioderma serricorne Fab. is considered a major insect pest of turmeric in storage and causes considerable loss to stored turmeric. In tropical countries, the insect is abundant through out the year (Nair in Nair et al, 101; Rao & Reddy, Indian Cocoa, Arecanut Spices J, 1990, 14, 67; Handbook of Agriculture, 1980, 543; Hort Abstr, 1987, 57, 577; 1960, 30, 2473; Purseglove et al, II, 541; Lakshmi et al, Andhra Agric J, 1991, 38, 106).

 

·     Of the defoliators, Udaspes foleus Cramer is the turmeric skipper reported as a specific and serious pest. As a control measure, hand- picking of caterpillars and pupae is recommended. Lema lacodairei Baly and other Lema sp. are serious defoliators in Orissa. Dusting 5% BHC is a suitable control. Other defoliators recorded on turmeric include Pseudocophora sp. Colasposoma splendidum (F.), Ceratobasis nair Locard, Cryptocephalus rajah (F.), etc (Nair in Nair et al, 101; Handbook of Agriculture, 1980, 542).

 

·     Some nematodes have also been recorded on the plant viz., Meloidogyne incognita, the root-knot nematode, Radopholus similis, the borrowing nematode and several others (Nair in Nair et al, 101).

 

·     Harvesting - The maturity of the crop is indicated by complete drying up of the plant including the base of stems. The crop is ready for harvest in c. 8 months after planting; the long duration varieties take 8½-9 months. In Tamil Nadu, the crop is harvested in January-March and in Andhra Pradesh in February-April. The dry leaves are cut close to the ground. The land is irrigated, if necessary, and ploughed in between the rows when planted on ridges. Otherwise the rhizomes are dug up with a crow bar or pick-axe. The rhizomes are collected and cleaned of the adhering earth and roots, and separated into rounds and fingers. A small portion of the field may be left, to be harvested a month later, for seed (Umrani et al in Nair et al, 90; Nair et al, 92; Venkateswaran, 209; Handbook of Agriculture, 1980, 1186).

 

·     Yield: The yield of raw rhizomes in a pure crop varies from 20- 22,000 kg/ha. It may go up to 30,000 kg/ha under exceptionally favourable conditions like suitable cultivar, heavy manuring and good irrigation. On an average, 20-25 percent of the raw rhizomes is obtained as the cured product. In recent years, Tamil Nadu has made rapid progress in increasing productivity per unit area and is now obtaining 30% higher yields (~. 6000 kg/ha of cured rhizomes) than in Andhra Pradesh (~. 4600 kg/ha) and 100% or more higher than in other states except Karnataka which has recorded an average of ~. 5500 kg/ha. Putting the crop under irrigation has been the main contributing factor (Handbook of Agriculture, 1980, 1187; George & Vellappan in Nair et al, 207; Reddy et al, Indian Cocoa, Arecanut Spices J, 1989, 13, 102).

 

·     Storage: For seed purposes, the rhizomes are heaped in shade and covered with turmeric leaves or the heap is plastered over with earth mixed with cowdug; in some places it is dusted with ash and sprinkled with water occasionally. The remaining produce is cured and stored in large quantities at the assembling centres. Turmeric is generally stored in air-tight underground pits lined and covered by rellu grass (Saccharum spontaneum) or date mats, before the onset of monsoon; the pits are opened after the rains. In Kerala, Andhra Pradesh and Orissa, turmeric is stored in ordinary godowns. In Kerala, the problem of storage is comparatively less as the major portion of the produce is exported immediately after the harvest. It is reported that due to the high oil content of turmeric produced in Orissa, storage in ordinary godowns does not pose any problem of storage pests. Moreover, turmeric is stored here in the raw state. Some amount of the produce is stored in godowns of State and Central Warehousing Corporations. Prophylactic measures including fumigation are followed to protect the produce from storage losses (Handbook of Agriculture, 1980, 1187; Lakshmanchar in Nair et al, 242).

 

6.   Other Practices

 

·     In Indian systems of medicine, turmeric is used to some extent as a stomachic tonic and blood purifier. It is also prescribed as an antiperiodic alterative. Mixed with warm milk it is said to beneficial in common cold. The juice of the fresh rhizome is used as an antiparasitic for many skin affections. Externally, it is applied to indolent ulcers, and a paste made from the powdered rhizome along with lime forms a remedy for inflamed joints. A decoction of the rhizome is said to relieve the pain of purulent ophthalmia. Oil of turmeric, distilled from the dried rhizomes, has feeble antiseptic properties. It is an antacid and, in small doses, acts as a carminative, stomachic, appetiser and tonic. In large doses, (2-4ml of concentrated solution), however, it appears to act as an antispasmodic inhibiting excessive peristaltic movements of the intestines (Chopra et al., Indian J. Med. Res.,1941, 29, 769).

 

·     Utilization: Turmeric (rhizomes or powder) is an auspicious article in all religious observances in Hindu households. It is a normal constituent of condiments, curry powders and prepared mustards. It is used also for dyeing wool, silk and unmordanted cotton to which it imparts a yellow shade in an acid bath. In spite of its poor light- fastness it is still used for dyeing cotton, sometimes in combination with other natural dyes like indigo and safflower to impart different shades. Turmeric was in use, until recently. in England for dyeing wool and silk in the formation of olive browns and other compound colours. It is used as a colouring matter in pharmacy, confectionery and food- industry. Turmeric paper is an official reagent in the British Pharmacopoeia for testing alkalinity. A diluted tincture of turmeric is suitable for use as a fluorescence indicator even in brown and yellow solutions (Chem. Abstr.,1938. 32, 6579).

 

·     The colouring matter of turmeric can be extracted from the powder either by direct solvent extraction or by extraction with aqueous alkali and subsequent precipitation with acid (Chem. Abstr., 1938, 326402; 1941, 35, 7656). Products containing the total active constituents of turmeric and useful in the treatment of gall complaints have been prepared from aqueous extracts of the rhizomes (Chem. Abstr., 1934, 28, 4179: 29, 5992; 1943, 37, 3230). Curcumin is used as dye for silk, paper, wood and foodstuffs in China (Mayer & Cook, loc. cit.).

 

·     History And Origin :Turmeric was known in India since ancient times. The origin of turmeric is believed to have been in South-East Asia. Scientists believe C. longa has arisen by a process of triphoidy, either from C. aromatica Salisb. or a form similar to it with 42 chromosomes. The cultivated species are said to have naturalized in some areas of North-Eastern parts of India and the island of Java. Turmeric is thought to have reached East Africa in the 8th century and West Africa in the 13th century. Thus the crop is distributed throughout the troipcal belt. But its cultivation as a spice is largely confined to India, South-East Asia and Indonesia (Nair, et al, 15; Purseglove et al, II, 533).

 

·     Curing: The process of curing consists of cooking the rhizomes in water until they become soft. Addition of a little cowdung is beleived to intensify the colour, perhaps due to alkalinity. Being unhygienic, it has been replaced by lime, sodium bicarbonate or sodium carbonate at 0.05-0.1% concentrations. The cooking should be thorough,  otherwise the product is liable to insect attack. The duration of cooking varies in different localities from ~. 30 min to 6 hrs. Studies have shown that curing of turmeric by sodium bicarbonate method registered the highest recovery of processed rhizome than the conventional cowdung method. Moreover, there was considerable savings in the quantum of water and fuel required for curing while the quality of the finished product remained unaffectd. The methods and equipment used for boiling vary from tract to tract. Perforated troughs immersed in a boiling pan are used most economically and efficiently as there is less wastage of fuel and time. Each boiling takes about 30 minutes and 700 kg of turmeric can be boilded at a time. A furnace designed for this method is used in Tamil Nadu; it uses dried leaves of turmeric as fuel.

 

·     The cooked rhizomes are allowed to cool gradually and spread out in the open to sun dry for 10-15 days with in termittent turning over to ensure uniformity in drying. Alternatively, mechanical dryers are used, maintaining temperatures between 50 and 60-C. The dried rhizomes are either rubbed on a rough surface or trampled upon to remove the outer skin and then polished to give them an attractive colour and appearence (Philip & Sethumadhavan in Nair et al, 198; Balashanmugam, S Indian Hort, 1991, 39, 214; Mohideen et al, ibid, 1990, 38, 49; Natarajan & Lewis in Nair et al, 143).

 

·     Polishing: In Tamil Nadu and Orissa, polishing is done in a turmeric polisher consisting of a polishing drum of expanded metal, horizentally mounted and rotated by a handle. The drum is covered on the outside with a light wrapping of woven wire to prevent the small pieces from falling through. It can take in a charge of 32 kg of turmeric and the polishing is complete in 7 minutes.

 

·     The polished product is subjected to colouring by dry or wet method. In the dry method, chemicals - mainly lead chromate (chemichrome) is dusted on the rhizomes and mixed well. But this is discouraged due to injurious nature of the chemical dye and usually wet colouring is preferred. In some areas a paste of turmeric added to an aqueous extract of turmeric is used for soaking the rhizomes and then drying them. In an improved method of colouring developed by the CFTRI, Mysore, the dried rhizomes are taken in wicker basket which is shaken continously while a prepared emulsion of castor seed paste, alum, sodium bisulphite, sulphuric acid and turmeric powder, is poured on it. These are then sun- dried. The out- turn of the dried product varies with the quality and ripeness of the raw tubers and ranges from 17-25% of the fresh material. The loss in weight due to full polishing is ~ 5-8% and half polishing ~. 2-3%. Cured and finished turmeric is brittle and has a shining yellow colour (Venkateswaran, 210; Philip & Sethumadhavan in Nair et al, 198).

 

      History of turmeric (Curcuma longa), its use, species diversity, variability, method of propagation, chemical con­stituents etc. have been presented. (Sasikumar, B., Indian Spices, 33(1), 2, 1996).

 

      Turmeric (Curcuma longd) is an important spice crop with many diversified uses. Processing of turmeric rhizomes freshly dug out of the earth is essential both for the devel­opment of an attractive colour, characteristic aroma and good commercial value. Processing technology adopted in Duggirala area of Guntur district has been presented with a view to explore the possibilities for mechanising and im­proving the processing techniques. Various unit operations involved in turmeric processing  presently carried out manu­ally can be mechanized by adopting related processing (Satyanarayana, V.V. and Sukumaran, C.R.; Andhra Agricultural Jour­nal, 46(3&4), 229, 1999).

 

      Turmeric is a major constituent of condiments and curry powders; it is very important to Indian cuisine. It is used in pickle as a preservative, and as a colouring matter in dairy products like butter, cheese, and in bakery products. In the West, it is commonly used to add colour to mustards used for garnishing popular snacks. In India, it is considered a safe and economical colour additive to Vanaspati (hydrogenated oil), being cheaper and harmless, and not interfering in    the test for detecting adulteration of vanaspati with the ghee. Besides,  it is being heat and storage stable and adds to shelf- life of vanaspati (Smith, Rep Trop Prod Inst, G165, 1982, 8; Kapur et al, Indian J    Technol, 1963, 1, 292).