1Central Potato Research Institute, Shimla-171 001, (H.P.).
2Central Potato Research Institute Campus, Modipuram, Meerut-250 110, (U.P.).
*CPRI publication number 1640.
Effect of low temperature, desprouting and GA treatment on the initiation and development of little tubers on physiologically old mother tubers during storage was investigated during 1995–98. In tubers stored at 20°C and desprouted thrice, little tuber initiation occurred 214 days after harvest. But in tubers subjected to high temperature (20°C) with desproutings for different periods followed by low temperature treatment (4°C) for different periods, it took at least 325 days for initiation of little tubers. When the tubers were subjected to low temperature (4°C) treatment for 197 days followed by storage at 20°C with desprouting twice, little tuber initiation occurred after 315 days. The number of little tubers produced per mother tuber ranged from 2 to 9 depending upon the cultivar. The proportion of little tubers weighing less than 0.5 g was as high as 75% in Kufri Sutlej. Cultivars differed in their response to treatments. While Kufri Chandramukhi produced on an average nine little tubers per mother tuber, Kufri Jyoti and Kufri Badshah produced only two little tubers per mother tuber. When the dormancy of mother tubers was broken by treatment with GA and thiourea, sprout growth started early but little tuber formation was severely affected. Total sugars, reducing sugars, soluble protein, free amino acids and total phenols were determined periodically in the mother tubers. There was no evidence of threshold level of these biochemical constituents at which little tuber formation would occur.
