BIOINFOLET - A Quarterly Journal of Life Sciences

An investigation on effect of weather parameters on incidence of Helicoverpa armigera infesting soybean (var. Gujarat Soybean – 4) was carried out at Main Oilseeds Research Station, Junagadh Agricultural University, Junagadh during Kharif, season of 2023. The activity of H. armigera commenced from 32^nd SMW (1^st week of August) and continued till 42^nd SMW (3^rd week of October) with a population of 0.32 to 2.81 larvae/plant. The peak (2.81 larvae/plant) incidence was recorded during the 37^th SMW (2^nd week of September). The activity of H. armigera resulted into leaf damage which ranged from 3.06 to 26.91 per cent during 32^nd SMW (1^st week of August) to 42^nd SMW (3^rd week of October) with highest (26.91%) damage during the 37^th SMW (2^nd week of September). There was no further damage after 43^rd SMW. The correlation analysis revealed that minimum temperature and morning vapour pressure had significant positive association with the population of H. armigera and leaf damage in case of soybean.