Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore641003, Tamil Nadu, India.
Two field experiments were conducted during 2003 and 2004 to evaluate the bioefficacy of certain newer insecticides against gram pod borer, Helicoverpa armigera Hubner and podfly, Melanagromyza obtusa Malloch on pigeonpea. Experimental results showed that the least Helicoverpa larval population of 2.0/plant was recorded on spinosad 45 SC (73 g a.i./ha) treatment followed by indoxacarb 14.8 SC (2.4/plant) as against a maximum population of 6.7/plant in the untreated check. The pod damage due to H. armigera infestation was the least (9.4%) in bifenthrin 10 EC (80 g a.i./ha) treated plots as against a maximum pod damage of 56.3 per cent in the untreated control. However, the grain damage due to podfly was the lowest in monocrotophos 36 WSC @ 270 g a.i/ha and was followed by bifenthrin 10 EC (25.6%). The untreated plot recorded maximum damage of 53.7%. Highest grain yield was recorded in bifenthrin treated plots (925.6 kg/ha) followed by indoxacarb (864.0 kg/ha) and spinosad 45 SC @ 73 g a.i/ha (841.1 kg/ha) as against the minimum yield of 432.7 kg/ha in the untreated control.
Helicoverpa armigera, Melanagromyza obtusa, insecticides, pigeonpea