Control of Helicoverpa zea in Tomatoes with Chlorantraniliprole Applied Through Drip Chemigation

Abstract

Chlorantraniliprole (=Rynaxypyr) is a novel anthranilic diamide insecticide that is of interest to vegetable growers because of its low mammalian toxicity and systemic properties. Field trials were conducted between 2006 and 2008 in North Carolina and Virginia to test the efficacy of chlorantraniliprole as a drip chemigation treatment on tomatoes. Drip chemigation of chlorantraniliprole at various rates and intervals significantly reduced the percentage of tomatoes damaged by tomato fruitworm (Helicoverpa zea) comparable to that typically achieved from multiple foliar applications of insecticides. The best control was achieved with two applications of chlorantraniliprole at 0.074 kg ai/ha, or a single application at 0.099 kg ai/ha. Residual ingestion bioassays showed that chlorantraniliprole was effectively taken up by the roots and was active in leaves up to 66 days after treatment (DAT), active in blossoms up to 22 DAT, but was not active in fruit. Drip chemigation of chlorantraniliprole may offer several advantages over foliar applications, including ease of application, reduced pesticide input into the environment, reduced worker exposure to pesticides, and reduced risk to beneficial arthropods. Accepted for publication 14 January 2010. Published 7 April 2010.