Foliar application of entomopathogenic nematodes, Steinernema masoodi, S. carpocapsae and Heterorhabditis indica for management of legume pod borer, Helicoverpa armigera infesting chickpea

Laboratory and field studies on bioefficacy of locally isolated entomopathogenic nematodes, Steinernema masoodi, S. carpocapsae and Heterorhabditis indica (Rhabditida: Steinernematidae, Heterorhabditidae) were evaluated against legume pod borer, Helicoverpa armigera (Lepidoptera: Noctuidae) infesting chickpea. In laboratory bioassays, S. masoodi [3 Î 10⁹ infective juveniles (IJs)/ha + jaggary 0.5% + glycerine 1% + ujala 0.01%]-sprayed chickpea leaves along with pods were offered to H. armigera larvae soon after spray, the cumulative mortality of 85% was obtained at 72 h in experiment 1 whereas in experiment 2, larval mortality declined from 95% to 75, 55 and 35% at 72 h when treated foliage were offered at 0, 1, 2 and 3 h post-spray. No larval mortality was recorded when treated foliage was fed at 16 and 24 h post-spray in both the experiments. In field experiments conducted at Kanpur and Meerut, reduced pod damage up to 12 and 11% were obtained by the foliar application of S. carpocapsae [3 x 10⁹ IJs/ha + glycerine + ujala] and H. indica [5 x 10⁹ infective juveniles (IJs)/ha + glycerine + teepol], respectively. Correspondingly, maximum grain yield of 26.85 and 21.50 q/ha were harvested by applying the above dosages resulting in 42 and 47% increase in yield over the untreated control.