Evaluation of Insecticides for Control of Heliothine Larvae on Cotton (Trial 2), 1996

Abstract

Abstract This test evaluated the effectiveness of larvicides for the control of TBW and BW larvae in cotton in Mississippi. Plots were 4 rows wide and 50 ft long with 4 untreated rows or a 10 ft planted buffer between plots. Plots were sampled at 3 to 4 day interval throughout the growing season for larvae in terminals and squares, square damage, and eggs in terminals. Twenty-five randomly selected terminals and squares in each plot were sampled, and treatment was initiated when population levels reached treatment threshold according to the Mississippi Cotton Insect Control Guide. Other pests occurring throughout the season were treated according to the Mississippi Cotton Insect Control Guide recommendations. All insecticide applications were applied with a high clearance spray tractoi equipped with two TX4 hollow cone nozzles per row traveling 4 mph and delivering 5 gpa. Plots within a replicate were sprayed sequentially to maintain true replicate integrity. Yield was determined by mechanically harvesting the center two rows of each plot. Spray applications were made 28 Jun 4, 10, 22. and 29 Jul, and 7 Aug. Rain prevented timely application for some applications and decreased the residual efficacy.