Evaluation of Selected Insecticide Mixtures Against Late Season Populations of Bollworm, Tobacco Bud-Worm and Beet Armyworm, 1992

Abstract

Cotton was planted on 6 Jul with plots consisting of 4 rows (102 cm centers) x 15 m. Treatments were arranged in a randomized complete block design, replicated 4 times. Applications were made with a high clearance sprayer calibrated to deliver 93.5 liters total spray/ha through Teejet X-12 hollow cone nozzles (2/row) at 2.1 kg/cm2. Insecticide treatments were applied on 8, 11, 18, and 28 Sep against an established population of bollworms and tobacco budworms (primarily tobacco budworms). Efficacy against bollworms and tobacco budworms was determined by examining 25 squares/plot for evidence of feeding damage and the presence of larvae on each of 3 observation dates. Efficacy against beet armyworms was determined by taking 10 sweeps/plot with a standard (38 cm diam) sweep net.