Improved varieties of elephant-foot yam are free of acridity, and have excellent cooking traits
ELEPHANT-FOOT YAM (Amorphophallus paeoniifolius) is a popular tuber crop of humid tropics, and it is widely grown in Andhra Pradesh, Kerala, Tamil Nadu and Pondicherry. A number of high yielding varieties of this promising tuber crop have been developed at the Central Tuber Crops Research Institute (CTCRI), and other State Agricultural Universities.
The improved varieties of elephant-foot yam are non-acrid, and endowed with excellent cooking qualities. The tubers are prescribed as medicine in ayurveda to treat piles, dysentery, asthma, swelling of lungs, vomiting and abdominal pain. It is used as a blood purifier. The paste of tubers is applied externally to reduce pain in arthritis.
Elephant-foot yam performs well in warm and humid belts. The humid weather helps in luxuriant growth of the foliage, and the dry conditions contribute to the corm development. The tuber crop does exceedingly well in light loamy soils with good drainage. It prefers partial shading, and it is grown as an intercrop in coconut groves and orchards in Kerala and Andhra Pradesh.
The improved varieties should be vegetatively propagated. The whole or cut tubers of 500-1000 g are used for planting. Whole tubers should be preferred to minimise rotting. Separate crops should be raised for seed production and commercial cultivation. The tubers should be dipped in cow-dung slurry and dried in shade before being planted. Bio-fertilizers and other beneficial microbial organisms should be added to the cow dung slurry to get good results from the crop.
The tubers should be planted in well-worked fields where pits of 30 cm x 30 cm x 30 cm are dug at a spacing of 90 cm x 90 cm. The pits should be filled with adequate quantities of organic manure, especially vermin-compost and powdered neem cake. The pits should then be mulched properly with leaf mould or paddy straw. February-March is the best time for planting in Kerala and northeastern India. As a rainfed crop, it can be planted in May-June or July with the onset of the rains.
The plants are robust, and they can be protected from sucking and chewing pests by resorting to sprayings with botanical insecticides. The crop should be irrigated lightly as and when necessary. Care should be taken to avoid water logging at any time. The field should be kept free of weeds to encourage vigorous growth of the shoots. The crop comes to harvest in 6-8 months after planting. The drooping and yellowing of the leaves will indicate the maturity of the crop, and with a shallow irrigation, the corms can be dug out. Care should be taken to prevent any injury to the corms while harvesting. They are then dried in shade and cleaned before sending to the market. The tubers should not be kept in airtight containers while transporting.
They should be packed in baskets or jute sacks. Protected by thick skin, they can stand long transportation well.