Effect of Climatic Factors on Chill Units Accumulation and Productivity of Apple Crop in Mountainous Region of Himachal Pradesh

Abstract

The present investigation was carried out for during 2016-2017 for Kullu and Shimla district of Himachal Pradesh. The results revealed that cumulative chill units of Kullu showed a decreasing trend of the order of 6.61 CU/year. Month-wise chill units accumulation (Nov-Feb) revealed maximum decrease of 2.54 CU for the month of February. Similarly, the cumulative chill units of Shimla also showed decreasing trend of the order of 10.9 CU/year and overall decrease of 337.9 CU over the last thirty-one years. The maximum monthly decrease of 5.19 CU for the month November at Shimla district. The average number of chill units available for the apple crop followed a decreasing trend as 1182 CU at Shimla followed by 558.29 CU at Kullu. The productivity of last five years (20012-2017) showed a decreasing trend of the order of 0.11 ton/ha/year for Kullu and 0.186 ton/ha/year for Shimla.