BIO-EFFICACY AND ECONOMICS OF CERTAIN NEW INSECTICIDES AGAINST GRAM POD BORER, HELICOVERPA ARMIGERA (HUBNER) INFESTING PIGEONPEA (CAJANUS CAJAN L.)

Two field experiments were conducted during Kharif, 2010 and 2011 to evaluate the bio-efficacy and economics of certain new insecticides against gram pod borer, Helicoverpa armigera (Hubner) on pigeonpea. Experimental results showed that the number of Helicoverpa larvae per plant were lowest in plots treated with chlorantraniliprole 20 SC (0.43), flubendiamide 480 SC (0.59) and spinosad 45 SC (0.85) as against untreated control plot (4.17) with 89.7, 85.9 and 79.6 per cent larval reduction over control, respectively. Pod damage due to pod borer, Helicoverpa was lowest in plots treated with flubendiamide (1.16%), chlorantraniliprole (1.26%) and spinosad (1.92%) with 88.7, 87.7 and 81.2 per cent reduction over control respectively. The untreated plot has recorded maximum pod damage of 10.22%. Highest grain yield was recorded in chlorantraniliprole treated plots (686.1 kg/ha) with 127.5 per cent increase over control, followed by flubendiamide (595.8 kg/ha) and spinosad (589.0 kg/ha) with 97.6 and 95.3 per cent increase over control respectively as against the minimum yield of 301.6 kg/ha in the untreated check. The cost effectiveness of chlorantraniliprole and flubendiamide was also high and very favorable with incremental cost-benefit ratios of 1: 4.64 and 1: 4.50 respectively, followed by indoxacarb (1: 3.67), emamectin benzoate (1: 3.13) and spinosad (1: 2.97).