Field Bio Efficiency of Insect Growth Regulators and Insecticides against Pod Fly, Melanagromyza obtusa in Pigeonpea (Cajanus cajan, L.)

Abstract

The present study on the bio efficacy of insect growth regulators and insecticides on pod fly was carried out during kharif 2021 in pigeonpea using Co 7 variety. An experiment was laid out using a randomized block design (RBD) with seven treatments and three replications. Insecticidal treatments consisted of four insect growth regulators and two insecticides along with untreated check and applications were made twice. Among the seven treatments tested, T4: Flubendiamide 480 SC @ 30 g a.i. ha-1 proved to be effective in reducing pod fly population (3.67 No/25 pods). The other treatments tested were found to be on par except T1: Buprofezin 25 SC @ 200 g a.i. ha-1 treated plots (6.33 Nos), whereas untreated check reported with 14.67 Nos at 14 DAS. At the same time, pod damage was also calculated and the lowest pod damage was recorded in T4: Flubendiamide 480 SC @ 30 g a.i. ha-1 and T5: Lufenuron 5.4 EC @ 30 g a.i. ha-1 treated plots and were significantly superior over other treatments and found to be on par with each other with 10.00 and 11.33 per cent, respectively. At two applications of treatments also, T4: Flubendiamide 480 SC @ 30 g a.i. ha-1 treated plots was superior over other treatments and recorded 3.15 Nos per 25 pods with 3.72 and 11.88 per cent pod and seed damage, respectively. After two applications of T4: Flubendiamide 480 SC @ 30 g a.i. ha-1 the pod fly damage reduction was upto 80.1 per cent and other treatments reported the damage between 42.2 – 78.0 per cent over untreated check. The highest yield was reported in plots treated with T4: Flubendiamide 480 SC @ 30 g a.i. ha-1 for its highest grain yield of 757.7 kg ha-1 with 43.2 per cent increase over untreated check. The other treated plots reported between 478.3 - 680.0 kg of grain yield ha-1 with 10.82-75.56 per cent increase over untreated check. The highest Benefit: Cost ratio was obtained in the plots treated with T4: Flubendiamide 480 SC @ 30 g a.i. ha-1 (1:1.6) and other treatments reported between 1:1.0 – 1:1.4 whereas untreated plots reported with lowest benefit cost ratio of 1:0.9.