Role of Weather Factors on Early Blight of Potato under Kashmir Valley Conditions

Abstract

The effect of weather factors on development of early blight of potato studied during the year 2009 and 2010 , indicated maximum apparent infection rate of 0.155 (unit/day) and 0.165 (unit/day) respectively. The temperature 26.47 and 27.32℃, relative humidity 92 and 91 per cent and precipitation 6.68 and 6.42 mm during 2009 and 2010, respectively, apparently favoured the maximum disease development during these periods. Temperature showed a significant and positive correlation with disease intensity, whereas relative humidity and precipitation showed positive but non significant correlation with disease intensity. Multiple regression analysis revealed that weather factors accounted for 65.5 per cent variation.