Evaluation of Certain 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 insecticides against gram pod borer, Helicoverpa armigera (Hubner) on pigeonpea. Experimental results showed that the pod damage due to pod borer, H. armigera was lowest (5.9%) in plots treated with acetamiprid and dimethoate, followed by fipronil (6.6%) and thiamethoxam (7.2%) with 42.2, 42.2, 35.3 and 29.4 per cent reduction over control respectively. The untreated plot has recorded maximum pod damage of 10.2%. Highest grain yield was recorded in fipronil treated plots (4.5 q/ha), followed by thiacloprid (4.2 q/ha) and dimethoate (4.0 q/ha) with 50.0, 40.0 and 33.3 per cent increase in yield over control respectively as against the minimum yield of 3.0 q/ha in the untreated check. However, the ICBR was highest in thiamethoxam (1: 7.8) and dimethoate (1: 6.2), followed by acetamiprid (1: 4.1) and thiacloprid (1:3.4).