Abstract
The present study was carried out during 2014-15 in the Kullu district of Himachal Pradesh, which is situated between 31º52’00” to 31º58’00” North latitude and 76º13’00” to 77º44’00” East longitudes.The cumulative chill units hours available for apple crop were calculated by using UTAH model for the period of 1986 to 2015 and a decrease of 6.38 chill units(CU) hours per year was recorded at Kullu Valley of Himachal Pradesh. Chill units for the last three decades i.e. 1986-1995, 1996-2005 and 2006-2015 also revealed a decreasing trend of the order of 63.79 CU decreased per decade.Monthly accumulation of chill unit hours during the same period for each winter month (November, December, January and February) revealed maximum decrease of 2.186 CU per year was observed for the month of February. Trend analysis of last five years 2011-2015 showed there was a huge decrease of 14.98 chill units per year. Data on apple productivity in Kullu district for last decade (2005-2014) showed a decreasing trend of the order of 0.183 tons/ha /year as per the regression equation y = -0.183x + 5.745. Thus the climatic conditions for apple cultivation in the Kullu district will be becoming unfavorable in the coming years.
Highlights
Apple is one of the most important temperate fruit crops in India which accounts for about 10 % of the total fruit production of the country
The objective of this study is to examine change in climatic parameters especially chilling units and associated changes in apple productivity in Kullu district of Himachal Pradesh
Data collection The data on daily maximum and minimum temperature were collected for the period of 1985 to 2015 from the regional office of India Meteorological Department, Shimla, for Bhunter meteorological station situated at Kullu district of Himachal
Summary
Apple is one of the most important temperate fruit crops in India which accounts for about 10 % of the total fruit production of the country. Decrease in productivity of apple crop in the recent years due to change in climatic conditions have become a serious concern of the growers in Himachal Pradesh. Apple trees develop their vegetative and fruiting buds in the summer and as winter approaches the developed buds undergo dormancy due to shorter day lengths as well as cooler temperatures.
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