Sandeep Kumar, Gaje Singh, D.V. Singh, Rajendra Singh, Gopal Singh, Alok, Vimal Kanaujiya, Akash Singh and Vikrant
Abstract
Pigeonpea (Cajanus cajan L. Mill sp.) is a valuable leguminous crop, which helps in the achievement of sustainable agriculture and soil fertility but is devastatingly affected by a complex of pod borers. The present study tested the seasonal incidence and correlation of major pod borers, Helicoverpa armigera, Maruca vitrata, and Melanagromyza obtusa with important abiotic factor in field conditions in the western Uttar Pradesh. The numbers of larvae were observed weekly in the untreated plots and were compared with the meteorological factors (temperature, relative humidity, and rainfall). H. armigera demonstrated maximum incidences of 9.00 and 9.60 larvae plant-1 in the 44th and 45th Standard Meteorological Weeks (SMW) of 2023 and 2024, respectively, and no significant relation to weather factors. M. vitrata had 14.80 and 14.20 larvae plant-1 in 44th and 43rd SMW which showed non-significant positive correlation with maximum temperature (0.212) and rainfall (0.289). Non-significant negative correlations were observed with minimum temperature (-0.102), morning relative humidity (-0.063) and evening relative humidity (-0.298) in 2023 and a significant positive correlation with maximum temperature (0.611). Nevertheless, non-significant correlations were observed with minimum temperature (0.247), morning relative humidity (-0.174), evening relative humidity (-0.276) and rainfall (-0.355) in 2024. M. obtusa reached its highest level at 9.20 and 9.60 larvae plant-1 in 45th SMW, and also had a significant positive correlation with maximum temperature (0.596) and morning relative humidity (0.607). A highly significant negative correlation was observed with minimum temperature (-0.725). However, non-significant correlations were recorded with evening relative humidity (0.376) and rainfall (-0.046) in 2023 and a significant positive correlation with morning relative humidity (0.593). Nevertheless, non-significant negative correlations were observed in minimum temperature (-0.395), evening relative humidity (-0.219) and rainfall (-0.428). A non-significant negative correlation was also found with maximum temperature (-0.194) in 2024. The findings reveal species-specific population dynamics and weather relationships, emphasizing the need for climate-based monitoring and integrated pest management strategies for sustainable pigeonpea production in western Uttar Pradesh.