Influence of abiotic factors on stem fly, (Melanagromyza sojae Zehntner) infestation in soybean (Glycine max L. Merrill)

Abstract

A field investigation was conducted during Kharif 2022 to study the seasonal incidence of soybean stem fly, Melanagromyza sojae (Zehntner) and its relationship with abiotic factors. Standard meteorological week (SMW) wise observations revealed that stem fly infestation commenced during the 30th SMW with 1.80 Percent infestation and persisted up to the 42nd SMW (28.66%). The infestation ranged from 1.80 to 42.00 Percent, reaching its peak (42.00%) during the 39th SMW. Stem tunnelling also initiated during the 30th SMW (0.73%) and attained a maximum of 19.49 Percent during the 39th SMW, before declining to 15.99 Percent by the 42nd SMW. Correlation analysis indicated a highly significant positive association of stem fly infestation with maximum temperature (r = 0.812**) and morning relative humidity (r = 0.896**), while wind speed (r = −0.657**) and minimum temperature (r = −0.573*) showed significant negative correlations. Stem tunnelling exhibited a highly significant negative correlation with wind speed (r = −0.759**) and a significant negative correlation with minimum temperature (r = −0.547*). The study demonstrated the strong influence of abiotic factors on stem fly population dynamics.