Impact of weather-related variables on the development of Phomopsis vexans (Sacc. and Syd.)-induced brinjal fruit rot

Abstract

The impact of weather-related factors such as temperature, relative humidity, total rainfall, wind speed, and sunshine hours in the progression of fruit rot in brinjal caused by Phomopsis vexans (Sacc. and Syd.) Harter during 2021 was studied by performing correlation, regression analysis and calculation of apparent infection rate (AIR) and area under the disease progression curve (AUDPC). Disease severity recorded was correlated with the weather factors and were subjected to regression analysis. The correlation of disease severity with the weather parameters revealed the significant but negative correlation between percent disease intensity and temperature (minimum) and bright sunshine hours. The percent disease severity and relative humidity (morning and evening) showed a significant and positive correlation with each other. According to the regression analysis, the combined impact of meteorological factors and brinjal fruit rot disease severity was moderately significant and accounted to 60% for the late transplanted crop. The crop that was transplanted on July 15, 2021, had the lowest AUDPC value (2201.50), while it was maximum in the crop transplanted on August 11, 2021 (2421.65), whereas, the highest and lowest value of AIR were recorded in the crops transplanted on August 11 and July 15, 2021, respectively.