Control of Tobacco Budworm and Boll Weevil, 1988

Abstract

A small-plot field study was conducted in a commercial cotton field near Austwell, Tex., to measure the efficacy of 11 treatments against tobacco budworm and boll weevil. Treatments were compared in 5-row by 50-ft plots of cotton planted 28 Apr on 30-inch rows. Each treatment was replicated 3 times in a randomized complete block. Treatments were applied with a CO2-pressurized (38 psi) backpack sprayer calibrated to deliver 4.4 gal total spray/acre through 2 size 3X hollow-cone nozzles/row. Heliothis larvae (n = 50) were collected from the test plots and reared to adulthood for identification of species. Applications were made 13, 18, and 23 Jul. Twenty-five randomly selected squares or bolls were inspected from each plot for the presence of tobacco budworm larvae and damage and for boll weevil damage on 17, 22, and 27 Jul. Seed cotton was hand-harvested from a 6.8-ft section of row in each plot for yield analysis.