Bioefficacy of Chlorantraniliprole 18.5 SC Against Pod Borer, Helicoverpa armigera (Hubner) and Pod Fly, Melanagromyza obtusa (Malloch) in Pigeonpea, Cajanus cajan (Linn.) Millsp.

Abstract

Background: Pod borer, Helicoverpa armigera (Hubner) and pod fly, Melanagromyza obtusa (Malloch) are important pod boring insects infesting the pigeonpea, Cajanus cajan (Linn.) Millsp. throughout the world. A number of synthetic insecticides are known to be effective against these borers but most of them have been phased out as a result of high toxicity to the pollinators and other biotic agencies, therefore, a new molecule, chlorantraniliprole has been tested for bioefficacy against these insect pests.Methods: The experiment was conducted during Kharif, 2017 in a Randomized Block Design (RBD) with 7 treatments and 3 replications. Observations were made to record pod borer, H. armigera and pod fly, M. obtusa maggot present before treatment imposition and 3, 7 and 14 days after each spray from five randomly selected and tagged plants/ plot. From the data recorded per cent reduction in population over control was calculated. The per cent pod damage was calculated by counting damaged pods out of healthy pods. The numbers of coccinellids and spiders were recorded on 5 randomly selected plants before treatment and 7 and 14 days after spray (DAS) in each treatment.Result: The chlorantraniliprole 18.5 SC was found most effective @ 200 ml/ha which was found at par with chlorantraniliprole 18.5 SC @ 150 ml/ha and chlorantraniliprole 18.5 SC (Market sample) @ 150 ml/ha for suppression pod borer, H. armigera and pod fly, M. obtusa. The yield was maximum and at par in the chlorantraniliprole 18.5 SC @ 200 ml/ha (18.25 q ha-1), chlorantraniliprole 18.5 SC @ 150 ml/ha (17.82 q ha-1) and chlorantraniliprole 18.5 SC (Market sample) @ 150 ml/ha (17.42 q ha-1). Predatory population of coccinellids and spiders after imposing the treatments declined to some extent at seven days after treatment, however, increased after 14 days. Based on the results, the use of chlorantraniliprole 18.5 SC @ 150 ml/ha was most effective to control pod borer and pod fly in pigeonpea crop.