Seasonal incidence of yellow thrips in relation to weather parameters on chilli

Abstract

Chilli (Capsicum annuum L.), a vital spice and commercial vegetable crop in India, faces significant productivity challenges due to pests such as yellow thrips (Scirtothrips dorsalis). This study, conducted at the VNMKV experimental farm, Parbhani, during summer 2022-23 and Rabi 2023-24, aimed to investigate the seasonal incidence of yellow thrips and their relationship with weather parameters. Parbhani Tejas variety, grown on a 100 m² plot under standard practices. Weekly observations of thrips populations on randomly selected plants were correlated with weather data using WASP 2.0 software. The results showed thrips infestations beginning 15 days post-transplanting in both seasons. During summer 2022-23, thrips populations peaked at 14.10 per three leaves in the 10th SMW before declining. Similarly, the Rabi 2023-24 season recorded a peak of 15.7 thrips per three leaves in the 47th SMW. Weather parameters showed varied correlations with thrips populations. Maximum temperature exhibited a significant positive correlation during Rabi (r = 0.446*), while minimum temperature showed a significant negative correlation (r = -0.605*). Rainfall, humidity, and wind speed displayed weak, non-significant correlations in both seasons. Regression analysis revealed that weather parameters explained 50.10% and 70.80% of the thrips population variation in summer and Rabi, respectively.