Influence of weather parameters on development of aonla rust disease in South-West Haryana

The progression of aonla rust disease was studied on two susceptible aonla cultivars viz., NA-7 and Chakaiya during the winter season of 2020-21. The disease severity was observed to be highly influenced by the variation in the temperature and relative humidity. A correlation matrix was developed to analyze the role of prevailing weather conditions on disease development. The disease severity was significantly and negatively correlated with average maximum temperature and exhibited significant and positive correlation with morning and evening relative humidity. Wind speed also played a significant role in disease progression as rust of aonla is an air borne disease. Multiple regression analysis was carried out which revealed the role of weather parameter in aonla rust development with R² value of more than 0.92. AUDPC value on Chakaiya was more i.e 1555.26 as compared to cultivar NA-7 (1407.77) which indicated the faster disease progression and susceptibility of the cultivar Chakaiya over NA-7. This study can be used further to develop a disease forecasting module for aonla rust.