Comparative efficacy of certain botanicals and bioagents against pod borer, Helicoverpa armigera on fieldbean [Lablab purpreus (L.)]

Abstract

The occurrence of field bean pod borer Helicoverpa armigera (Hubner) in 2013-2014 Kharif season commences from 6th standard week (February second week) with an average of 0.25 larvae/plant. There after declined trend was observed. It was observed that the temperature between 25-35o C favored the multiplication of gram pod borer whereas more than 35o C temperature might be attributed as to decline of the larval population. The results obtained on an average pod damage percentage of Helicoverpa armigera (Hubner) on pods damage percentage evaluating each treatment for pod borer management have been described thoroughly all the treatments were found to be significantly over the control. NSKE gave the highest percentage of pod damage of pod damage reduction and emamectin benzoate 5SG was found to be next effective treatment (13.23%). The yield and cost benefit ratio (C:B ratio) was also found maximum in NSKE treated plots. However emamectin benzoate recorded second highest C:B ratio of 1:2:25. Among bio-agent HaNPV@250 LE showed maximum efficacy against pod borer with C:B ratio 1:2:10. The plant products also achieve certain range of mortality but are less effective when compare to new insecticide molecules because they are highly specific and effective.