Influence of meteorological factors on potato late blight development in North-western plains of India*

The analysis of 7 years meteorological data on blight development in NW Plains of India revealed that late blight severity was positively correlated with maximum relative humidity (r=0.467), rain, dew and cloudy days and negatively with minimum temperatures (r=0.630*). Late blight occurrence was normally associated with drop in air temperatures <26.0°C) and rise in the morning relative humidity (RH>85%). Blight could appear in absence of rains also. The multiple regression analysis revealed that maximum temperatures and minimum (afternoon) RH had high influence on disease severity.