Weather based operational plant protection of leaf spot disease of groundnut

Abstract

Sensitivity of weather to the incidences of the leaf spot disease on groundnut was studied.  Using data collected by PPQ & S during regular survey in different parts of the country it was observed that the disease occurred more frequently in Andhra Pradesh, Karnataka, Gujarat and Maharashtra both in kharif and rabi seasons from 1988-1998.  Weather systems causing drop in temperature associated with  rainfall and overcast condition leading to increase in relative humidity favoured incidence of the disease particularly when the crop was in pod formation to maturity stages. Decrease in maximum temperature £30° C and increase in  morning and afternoon relative humidity        ³ 80% and 60% respectively under cloudy condition (2 - 8 okta) associated with  rainfall were found to be congenial for the development  of the disease in moderate to severe intensities. This weather based information along with field observations on incidence of this disease could be used to forewarn the incidence of the leaf spot disease on groundnut for taking plant protection measures at appropriate time through Agromet Advisory Service.