Evaluation of Insecticides for Suppression of Sorghum Midge on Sorghum, 1994

Abstract

Abstract Selected insecticides were evaluated for sorghum midge control at the Texas Agricultural Experiment Station Research Farm near College Station, TX. Hybrid grain sorghum (ATx399 × RTx430) was planted 20 May in rows spaced 30 inches apart. Insecticide treatments were compared in plots, 8 rows × 40 ft long, arranged in a RCB design with 4 replications. Insecticides were applied to the middle 2 rows of plots. Insecticides were applied between 0800 and 0900 hours CDT by using a hand-held backpack sprayer with TX-3 hollow cone nozzles at 35 psi, producing a finished spray volume of 5.6 gpa. Application began when 10-30% of the panicles were flowering; insecticides were applied 10, 13, and 16 Jul. Adult sorghum midge abundance was determined just prior to each application by counting the number of sorghum midges on 10 individual sorghum panicles enclosed in clear plastic bags. The panicles were cut from the plant and returned to the laboratory for examination and sorghum midge counts. Grain yield data were collected from the 2 middle rows per plot. Panicles were hand harvested from selected 8.75 ft sections of row/plot and mechanically threshed. Data were statistically analyzed by using ANOVA and LSD.