The lack of quality planting materials, particularly improved varieties, is a major constraint in expanding area under tuber crops.
Naturally bulky, with very low multiplication rate and due to demand as a food source or for cash generation lead to very low availability of good quality planting materials with the farmer.
Even though a good array of high yielding varieties are available in the research stations, the above factors contribute to their meagre spread among the farming community.
“When compared to rice or wheat, tubers can give satisfactory production even in partially shaded area and do not need much investment or labour compared with paddy or wheat. Encouraging cultivation of tubers like elephant foot yam is a good way of protecting farmers from total crop loss due to vagaries of nature” says Dr C. P. Robert, Programme Coordinator, CARD (Christian Agency for Rural Development)-Krishi Vigyan Kendra, Pathanamthitta District, Kerala.
It is a common practice in elephant foot yam cultivation that the cut portions of tubers containing the central ring are used as planting material. The big sized tubers usually produce 2-3 sprouts (setts) in the central ring and farmers divide the tubers according to the position of sprouts in the central ring. This leads to unevenly sized tubers with varying weights and also non-uniform growth in the field and wastage.
The other disadvantage is using big sized tubers results in low multiplication rate of improved varieties and thereby increases the production cost.
Change in liking
Traditionally farmers use setts from one kg size tubers as planting material and the harvested tubers weigh 4-6 kg in size.
Lately, due to the change in consumer preference the bigger tubers are less favoured in the market and fetch lesser price than smaller sized ones.
The Kendra solved this problem by developing a pre-sprouting technique for the crop which yields small sized tubers.
Explaining how it is done Dr. Robert says:
“The central bud is split into setts by passing the knife half way through the tubers. For example a two kg sized seed tuber is half split into 8 setts and after 2-3 hrs fresh cow dung is applied on the cuts.
“The tubers are then kept for bud sprouting. Within 30-40 days the cut segments develop sprouts and are separated for planting as independent setts.
“These can be planted at a spacing of 60cm x 60 cm while in traditional system a wider spacing of 90 cm x 90 cm is required. About seven tonnes of seed tubers is needed for planting in one hectare of land where as in traditional system about 9-12 tonnes is required.”
According to Mr. Mohanan Pillai Varikolil, a Karshakothama award-winning yam farmer in the district, “The use of sprouted small setts is more economical as the tubers are small in size and fetch a better price in the market.
The small tubers are easy to harvest and there is less weed competition due to the closer spacing adopted.” “The technique is a modification of the Central Tuber Crops Research Institute (CTCRI) developed technology and has been made more farmer friendly by addressing both seed production and commercial production needs” says Rincy K Abraham, Subject Matter Specialist(Horticulture).
CARD KVK refined the technique a little more and today in the region the crop has much relevance as insurance coverage to farmers during periods of erratic weather and can give satisfactory yields in higher temperature.
For more information on the same farmers can contact Rincy K Abraham, Subject Matter Specialist (Horticulture), CARD, (Christian agency for rural development), Krishi Vigyan Kendra, Pathanamthitta, email: email. firstname.lastname@example.org, Phone: 0469 2662094, 09645027060.