Exploring weather dynamics of Fusarium wilt incidence caused by Fusarium oxysporum in chilli (Capsicum annuum L.)

Abstract

A field experiment was carried out using the Bullet Lanka variety to study the impact of weather parameters along with the different dates of transplanting on the chilli crop against Fusarium wilt during the rabi season of 2021-22 at the agricultural farm of Palli-Siksha Bhavana (Institute of Agriculture), Visva-Bharati at Sriniketan of Birbhum district, West Bengal. This study employed epidemiological tools such as area under disease progress curve (AUDPC), apparent infection rate (r), and multiple regression models to find out the disease dynamics. The highest disease incidence was observed at a maximum temperature of 30.72°C and a minimum temperature of 21.58°C, with morning and evening relative humidity levels of 72.43% and 68.26%, respectively, and in the absence of rainfall. The AUDPC and r values were lowest in the crop transplanted on 15^th November 2021, while they were highest in the crop transplanted on 5^th November 2021. Correlation study exhibited, that maximum temperature and minimum temperature showed a positive relationship with PDI, whereas morning and evening relative humidity and rainfall showed a negative relationship with PDI. Further, the R² value obtained from the multiple regression equation revealed that the combined effect of all environmental parameters, including maximum and minimum temperature, morning and evening relative humidity, and rainfall on disease development ranged from 81% to 90% at all three transplant dates.