Better profits with smaller sized tubers
Mohanan pillai ,Varikolil, Pandalam is a progressive farmer with many years of experience in cultivation of tuber crops like Elephant Foot Yam, Cassava, Tania and Taro. He used to cultivate Elephant Foot Yam as an inter crop in Banana. As per the traditional practice, he used to plant elephant foot yam setts of 750gm to 1 kg size during February – March period in his farm. He used to get an yield of 30-35 t/ha. According to him the high cost of the planting material, difficulty in transportation of the tubers to his 2 ha farm and non uniform establishment were the problems he used to face every year.
During 2009-10, Krishi Vigyan Kendra , Pathanamthitta conducted On Farm Trial of mini sett multiplication technique developed by CTCRI in the field of Sri Mohanan Pillai and other farmers in Pandalam Thekkekkara. But the farmers rejected the technology due to very poor establishment and large percentage of very small tubers of less than 1 kg. In subsequent years the KVK conducted refinement of the technology by increasing the sett size to 250gm and 500gm and found that sett size of 250gm can address the need for higher multiplication ratio, lesser quantity of planting material and can substantially increase the percentage of marketable sized tubers. Even though establishment was better and more uniform, drying of the unsprouted tubers due to hot sun during February -March was the problem. Also the farmers expressed difficulty in preparation of the setts with sprouts. During 2012-13 , a pre sprouting technique was developed for the production of smaller setts.
At the time of preparation as seed material by removal of the central bud, the tubers are half split into setts of 250 gm by passing the knife half way through the tubers but not completely separated. ie, a 2kg sized seed tuber is half split into 8 setts. 2-3 hrs after splitting the setts, fresh cow dung is applied to 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 sprouted setts. These small sized setts 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. 7 tons of seed tubers is needed for preparing the 27,777 setts of 250gm required for planting in one hectare of land where as in traditional system about 9-12 tons is required for preparing 12,345 setts
According to Sri Mohanan Pillai Varikolil who is the “Karshakothama” award-winning farmer in the district, “the use of sprouted small setts is more economical as the 1.5-2 kg sized tubers produced using the pre-sprouted setts, received better price in the market”. Compared to bigger tubers produced using the bigger sized setts, he received 35% extra price for the small tubers. He also obtained comparable production of 33.3 t/ha from the sprouted small setts at 28% lesser cost of production. “There is uniform establishment and less weed competition due to the closer spacing adopted. Also the small tubers are easy to harvest” He says. The more number of small sized whole tubers increased the availability of planting materials of improved varieties like Gajendra and SreePadma in the locality. The technology is practiced by more than 200 farmers in the Pandalam Thekkekkara and Kunnamthanam Panchayaths now.