Turmeric needs heavy manuring. it is not a common practice to manure turmeric with chemical fertilizers. Usually, 40-50 tonnes of farmyard manure is applied at the time of preparing the land. About 1200-1800 kg of groundnut-cake is also applied after planting , in two split doses, the first two months after planting and the second a month and ahalf later. However, instead of groundnut-cake chemical fertilizers to supply 30 kg each of N, and P2O5 and 60 kg of K2O per ha may also be applied in split doses in the case of ginger.
VARIETIES. The cultivated varieties show considerable variation in the size and the colour of the rhizomes and the curcumin content. More than 5 per cent curcumin content and lemon yellow, orange or orange yellow colours of the turmeric powder are prepard in the foreign market. Turmeric marketed from the Alleppey market (Kerala) known as Alleppey turmeric, is reported to contain a higher percentage of curcumin and is preferred in foreign markets for its colour. The Patna variety is noted for its deep colour. Of the two types cultivated in Maharashtra, 'Lokhandi' has bright coloured hard rhizomes and the other has light coloured soft rhizomes. The popular commercial varieties in Andhra Pradesh are 'Duggrila' of 'Guntur' and 'Tekurpeta' which has long, stout, smooth and hard fingers. 'Kasturi Pasupa' of the Godavari delta, the 'Armoor' type of Nizamabad area and the 'Chaya Pasupa' are the other important varieties of Andhra Pradesh.
HARVESTING AND CURING. The crop is ready for harvesting in about 7 to 9 months after sowing depending upon the variety. The aromatica type mature in about 7 months and the longa type in about 9 months and the intermediate types in about 8 months. The dry leaves are cut close to the ground. The land is irrigated, if necessary and ploughed in between the rows if the crop is planted on ridges. Otherwise a crowbar is used. The rhizomes are dug up.
The curing quality and the proportion of the cured and dried produce to the green produce depend mainly on the variety. Mother-rhizomes give a higher curing percentage than the fingers are seperated. If need be, the former is kept for seed and the latter is cured for selling. The green rhizomes are boiled in water till a froth comes out and white fumes appear giving out a characteristic odour. After cooking, the rhizomes would be soft and would yield when presseed between the fingers. The quality of the final product, including its colour and aroma depends largely on the right amount of curing. The boiled rhizomes are spread out on a clean floor and allowed to dry in the sun for about 10 to 15 days. They are stirred 3 or 4 times to ensure uniform drying. The rounds and fingers are dried separately. The former takes more time to dry, when fully dried the turmeric becomes hard and stiff. The dried turmeric is rubbed against the hard surface of the drying floor or trampled under feet covered with pieces of gunny cloth. The scales and the root bases are separated by winnowing. Clean & big pieces are separated out since they fetch a premium price. The broken bits are taken separately.
PRESERVATION OF SEEDS. Rhizomes for seed are generally heaped in the shades of trees or in well-ventilated sheds & covered with turmeric leaves. Sometimes the heap is plastered over with earth mixed with cowdung.
YIELD. The yield of the pure crop varies from 20,000 to 22,000 kg per ha. Under exceptionally favourable conditions, viz. abundant manuring and plentiful irrigation, it may be as high as 30,000 kg per ha. The cured produce is 20 to 25 per cent of the fresh rhizomes by weight.
