Insecticide Efficacy on Beet Armyworm Infestations in Open and Closed Cotton Flowers and Effects of Flower Infestation on Boll Abcission

Abstract

In 1988 severe beet armywonn (BAW) infestations resulted in damaged cotton flowers and foliage. Some insecticide applications failed to eliminate larvae in the flowers because applications were applied before the flowers opened. Applications made after flowers were open were more effective. In 1989, tests were conducted to define further these results. Karate™ applied when cotton flowers were open achieved 90% control compared to 9% when flowers were closed in one test, and 97% compared to 13 %, respectively, in a second test (P\0.01). A higher percentage (18 %) of cotton bolls was shed on day 7 following flower infestations than were shed (6 %) when flowers were not infested.