Utilizing Nuclear Polyhedrosis Virus for the Biological Management of Chickpea Pod Borer (Helicoverpa armigera) in Organic Chickpea Production

Chickpea (Cicer arietinum L.) is one of the most important organically cultivated pulse crops of our country. The pod borer, Helicoverpa armigera Hubner (Lepidoptera: Noctuidae) is the strategic pest that determines its production quantum to a great extent. Since last few years the organic agriculture has been getting attention of consumers as well as growers because of safety concerns. The pod borer causes huge losses in chickpea crop. It can be effectively managed through synthetic insecticides; however, they are prohibited under organic crop production system. Under such situation, nuclear polyhedrosis virus (NPV) is one of the promising crop protection practices for managing this pest. The Chickpea crop was monitored continuously for two successive cropping seasons (2019-20 and 2020-21) to get the native nuclear polyhedrosis virus. Due to its non-availability, the viral formulation was procured from the market and evaluated against pod borer under field conditions. The survey showed that there was no natural infection of the nuclear polyhedrosis virus in pod borer larvae at the research area of an organic farm. Bioefficacy field trials showed that NPV formulation was effective in controlling this pest during the 2021-22 and 2022-23 crop seasons. The findings indicated that NPV at a concentration of 1.5 ml per liter of water reduced 59.4% of the pest population after 7 days of spray, which reached up to 64.0% after 10 days. A 2.0 ml per liter concentration caused a higher reduction after 7 and 10 days. There was no positive correlation between male adult catch and ETL with weather factors. The formulation did not cause any type of toxicity on the crop and it was found safer for natural enemies viz., honeybees, yellow wasps, and Chrysoperla sp. It is concluded that HaNPV application can contribute in effective management of chickpea pod borer. In addition, being natural this virus safe for ecosystem and hence it can be an ideal approach under an organic crop production system to provide a protective umbrella against this pest without any hazardous effects on crops as well as beneficial insects.