Efficacy of Seed Treatment and Foliar Application of Against Soybean Stem Fly Melanagromyza sojae

A field experiment on the effectiveness of seed treatment and foliar application of insecticides againstsoybean stem fly Melanagromyza sojae (Zehntner) was carried out at the All India Coordinated ResearchProject (AICRP) on Soybean, Gandhi Krishi Vignan Kendra (GKVK), Bengaluru, Karnataka duringkharif 2017. The seeds treated with thiamethoxam 30FS @ 10 ml/kg seed and foliar application ofthiamethoxam 25WG 0.40 g/ l at 30 days after germination (DAG) were found effective. It was on par withseeds treated with imidacloprid 48FS @ 1.25 ml/ kg seed and foliar application of imidacloprid 17.8SL@ 0.50 ml/ l at 30 DAG. The plots treated with these gave higher grain yield of 1794.48 and 1678.89 kg/ha, respectively. Higher net gain of 1: 4.22 was obtained from the seeds treated with thiamethaxom 30FS@ 10 ml/ kg seed and foliar application of thiamethoxam 25WG 0.40 g/ l at 30 DAG; and it proved to behighly cost effective. The foliar application of chlorantraniliprole 18.5SC @ 0.30 ml/ l at 10 and 30 DAGwas equally effective compared to thiamethoxam and recorded the C: B ratio of 1: 3.94. The plots treatedwith quinalphos 25EC @ 2 ml/ l at 10 and 30 DAG led to the least stem tunneling of (26.73%) and thelow grain yield of 1177.78 kg/ ha.