Chemical Control of Cotton Bollworm and Tobacco Budworm on Cotton, 1985

Abstract

Abstract ‘Stoneville 213’ cotton was planted 7 May on rows spaced 40 inches apart. The test area received 2 inches of rain on 8 May, 1 inch on 21 May, 0.1 inch on 19 Jun, and 0.8 inch on 20 Jul. The experiment was arranged in a randomized complete block design with 4 replications of 18 treatments. Treatment plots were 12 rows wide and 60 feet long. Insecticides were applied to the inner 6 rows of each plot, leaving a 6 row buffer between contigious plots. Insecticide applications were made with a high-clearance, self-propelled sprayer calibrated to deliver 4 gal of solution per acre through two TX-3 hollow cone nozzles per row at 43 psi and 4 mph. Spray applications were made 12, 18, and 25 Jul, and 1 Aug. Damage assessments and density counts of bollworm/budworm eggs and larvae were made 11, 17, 23, and 30 Jul, and 6 Aug. Counts consisted of inspecting 30 plant terminals per plot for bollworm/budworm larvae and eggs. In addition, 30 squares, one-third grown or larger, per plot were selected at random and examined for bollworm/budworm damage. Yield was determined by hand harvesting cotton from plants in two, 20-ft row sections per plot.