Contribution of weather factors to the population fluctuation of major pests on small cardamom (Elettaria cardamomum Maton)

Abstract

Cardamom crop was found infested with number of pests viz., thrips, shoot borer, shoot fly and red spider mite during 2013, 2014 and 2015. The seasonal incidence of cardamom thrips peaked during January to March; shoot borer during March to May; shoot fly during April to June and red spider mite during March- April. Thrips population showed negative correlation with rainfall and morning relative humidity whereas, positive correlation with sunshine hours. Similar associations were observed in shoot borer and mite. But in the case of shoot fly, rainfall positively influenced its occurrence and temperature had negative association. Rainfall is the deciding factor in lowering thrips to a maximum of 41 per cent. Maximum temperature hampered shoot borer population to an extent of 35 per cent. Relative humidity (evening) contributed about 18 per cent in enhancing shoot fly occurrence. Minimum temperature influenced the mite incidence positively to 38 per cent.