In India, it is reported that turmeric is grown in an area of approximately 194,000 hectares with an annual rhizome production of around 892,000 tons. The main turmeric growing states are Andhra Pradesh, Assam, Karnataka, Kerala, Maharashtra, Orissa and Tamil Nadu. Erode (Tamil Nadu) and Sangli (Maharashtra) are the major producers and trading centers of turmeric in Asia. Indian turmeric is considered the best in the world market because of its high Curcumin content.
Cultivation Practices
Turmeric can be grown in diverse tropical conditions from sea level to 1500m above sea level, at a temperature range of 20-35 oC with an annual rainfall of 1500 mm or more, under rain-fed or irrigated conditions. Though it can be grown on different types of soils, it thrives best in well-drained sandy or clay loam soils with a pH range of 4.5-7.5 with good organic status.
The land is prepared with the receipt of early monsoon showers. The soil is brought to a fine tilth by giving about four deep ploughings. Hydrated lime (500 kg/ha) has to be applied for laterite soils and thoroughly ploughed. Immediately with the receipt of pre-monsoon showers, beds of 1.0 m width, 15 cm height and of convenient length are prepared with spacing of 50 cm between beds. Planting is also done by forming ridges and furrows.
Whole or split mother and finger rhizomes are used for planting and well developed healthy and disease-free rhizomes are to be selected. Small pits are made with a hand hoe on the beds with a spacing of 25 cm x 30 cm. Pits are filled with well decomposed cattle manure or compost, seed rhizomes are placed over it then covered with soil. The optimum spacing in furrows and ridges is 45-60 cm between the rows and 25 cm between the plants. A seed rate of 2,500 kg of rhizomes is required for planting one hectare of turmeric.
Farmyard manure (FYM) or compost at 30-40 t/ha is applied by broadcasting and ploughed at the time of preparation of land or as basal dressing by spreading over the beds or in to the pits at the time of planting. Fertilizers at 60 kg N, 50 kg P2O5 and 120 kg K2O per hectare are to be applied in split doses. Zinc at 5 kg/ha may also be applied at the time of planting and organic manures like oil cakes can also be applied at 2 t/ha. In such case, the dosage of FYM can be reduced. Integrated application of coir compost (at 2.5 t/ha) combined with FYM, biofertilizer (Azospirillum) and half recommended dose of Nitrogen, Phosphorous and Potassium (NPK) is also recommended. Weeding has to be done thrice at 60, 90 and 120 days after 4 turmeric planting depending upon weed intensity. In the case of irrigated crop, depending upon the weather and soil conditions, about 15 to 23 irrigations are to be given in clayey soils and 40 irrigations in sandy loams.
Turmeric can be grown as an intercrop in coconut and areca nut plantations.
Harvesting
Depending upon the variety, the crop becomes ready for harvest in 7-9 months after planting during January-March. Early varieties mature in 7-8 months, medium varieties in 8-9 months and late varieties after 9 months. The land is ploughed and the rhizomes are gathered by hand picking or the clumps are carefully lifted with a spade. The harvested rhizomes are cleared of mud and other extraneous matter adhering to them.