Impact of Rainfall on Area and Production of Rabi Oilseed Crops in Himachal Pradesh

The present study was carried out to assess the impact of rainfall on the spread, production and yields of rabi oilseed crops in Himachal Pradesh during the past forty years (1968-69 to 2007-08). Year-wise trend analysis in rapeseed-mustard indicated a significant increase in area, production and productivity while a significant decrease was observed in linseed with time. Pentadwise shift indicated 71.7% increase in the area under rapeseed-mustard during 8^th pentad over 1^st pentad which might be due to 92.6% increase in rain fall during 8^th pentad over 1^st pentad. The technological inputs including improved varieties resulted in 105.6% increase in production and 20.4% increase in productivity. Pentad-wise shift in rapeseed-mustard area also exhibited a significant positive correlation with rainfall. In linseed, pentad-wise shift indicated a drastic reduction in area (78.8%), production (89.3%) and productivity (51.2%) during 8^th pentad over 1^st pentad. There was a negative and non-significant correlation of area with rainfall. The study indicates that under rainfed conditions, the farmers preferred rapeseed-mustard over linseed. Linear regression analysis indicated that the increase in seasonal rainfall may not be the sole reason for area expansion in rapeseedmustard. On the other hand, a much part of variation in area as well as production in linseed appeared be due to variation in seasonal rainfall.