Effect of Weather Factors on the Incidence of Alternaria Leaf Blight, White Rust and Powdery Mildew of Mustard

The analysis of simple correlation between various weather factors and altemaria leaf blight, white rust and powdery mildew revealed that there was a significant positive correlation with maximum air temperature, minimum air temperature, mean air temperature, sunshine period, crop age and PDIs of these disease except between minimum air temperature, mean air temperature, sunshine period, crop age and PDIs of these diseases except between minimum air temperature and leaf blight incidence. The multiple regression analysis showed that among the various weather factors which could influence the incidence of diseases, sunshine and crop age were highly significant. Maximum, minimum and mean air temperatures were significant for powdery mildew only.