IRRIGATION REQUIREMENTS OF CHIPPING POTATO CULTIVARS UNDER WEST-CENTRAL

Field experiments were conducted during 2002-04 to evaluate the performance of two chipping potato cultivars Kufri Chipsona-1 and Kufri Chipsona-2 under different irrigation levels in sub-tropical conditions of west-central plains. Number of stems and compound leaves did not vary significantly with irrigation levels. However, consistent decline in processing- grade and total tuber number ha -1 were observed under water stress. Like tuber number, processing-grade tuber yield, total tuber yield, biomass yield and average tuber weight also decreased with decrease in irrigation frequency from 15 mm to 35 mm cumulative pan evaporation (CPE). Cv. Kufri Chipsona-1 had higher processing-grade tuber yield, total tuber yield and biomass yield as compared to Kufri Chipsona-2. Efficiency of water use increased linearly (81.1 to 146.4 kg tubers ha-mm -1 ) in response to water stress. Across the irrigation levels, cv. Kufri Chipsona-1 (116.4 kg tubers ha-mm -1 ) had higher water use efficiency than Kufri Chipsona-2 (101.7 kg tubers ha-mm -1 ). Specific gravity was higher under frequent irrigation (15 to 25 mm CPE). Tuber dry matter did not show significant differences but more acceptable chip colour was observed in less frequently irrigated treatments (30 and 35 mm CPE). Highest net income was obtained with irrigation scheduled at 15 mm CPE (Rs. 55,066 ha -1 ), but it was at par with 20 mm CPE (Rs. 52,717 ha -1 ).