Title: Survey for the Occurrence of Powdery Mildew and It’s Effect of Weather Factors on Severity of Powdery Mildew in Guntur District
Abstract: A roving survey was undertaken on the incidence and severity of powdery mildew disease during rabi 2015-16 in Guntur district of Andhra Pradesh. Disease incidence and severity of powdery mildew were surveyed in villages of Tadikonda, Veticherukuru, Pedanandipadu and Kakumanu mandals of Guntur district. Incidence was ranged from 13.69% (Pedanandipadu mandal) to 87.01 % (Tadikonda mandal) incidence and severity were ranged from 11.61 (Kakumanu mandal) to 88.08% (Tadikonda mandal), respectively. Correlation studies with weather parameters and crop age on powdery mildew disease severity revealed that positive correlation of disease was recorded with crop age and maximum temperature. Multiple regression analysis yielded seven distinct equations with R2 values ranging from 0.991 to 0.412 (P < 0.05). However, the best-fit equation was obtained in maximum temperature, wind speed, RH (8.30 am), Minimum temperature as independent variables showed 86.6 per cent role of tested independent variables on powdery mildew severity.