Control of Heliothis SPP. in Cotton, 1982

Abstract

Abstract Two full season studies were conducted at the Red River Valley Agricultural Experiment Station, Bossier City, LA, to determine the efficacy of various commercial and experimental insecticides in controlling Heliothis spp. and boll weevils on cotton. Plots in the first test were 8 rows x 64.0 m (1.02 n centers). Plots in the second study were 4 rows x 30.5 m (1.02 m centers). Insecticides were applied with a high-clearance sprayer equipped with a CO2 system for spraying small plots. Insecticides were applied in 11.4 liters of water with TX-3 hollow cone nozzles spaced 50.8 cm apart. Treatments in the first study were applied on Jul 27, Aug 3, 9, 18, 23 and 30. Guthion 2L (0.25 lb ai/acre) was added to the insecticides when weevil pressure warranted its addition. In the second test, insecticide applications were made on Jul 28, Aug 4, 10, 16, 24 and 31. No weevil material was added to the insecticide treatments in the second study. All plots in both tests were oversprayed with Azodrin 5 (0.5 lb ai/acre) for two-spotted mite on Aug 13. Following the sixth treatment in late Aug, both tests were oversprayed the remainder of the season following standard control practices. Yields were determined by mechanical harvest of the center 4 rows of each plot on Oct 20 and 21 in the first test and the center 2 rows of each plot on Oct 15 in the second study. Insect populations and plant damage were monitored following insecticide applications by examining 25 terminals and 25 squares/plot.