Evaluation of Insecticides for Suppression of Sorghum Midge on Sorghum, 1991:

Abstract

Abstract An organophosphate and a pyrethroid were evaluated for sorghum midge control at the Texas Agricultural Experiment Station Research Farm near College Station, TX. Grain sorghum was planted 28 May on rows spaced 30 inches apart. Insecticide treatments were compared in plots, 6 rows X 35 ft long, arranged in a randomized complete block design with 4 replications. Insecticides were applied using a hand-held backpack sprayer in the inner 2 sorghum rows through TX-3 hollow case nozzles at 36 psi with a spray volume of 6.4 gal/acre. Applications began when 25-30% of the panicles were flowering; treatments were applied on 24, 27, and 30 July. Data on kernel loss and grain yield were collected from one of the 2 inner rows. Adult sorghum midge abundance was determined just prior to each application by counting midges on 10 individual sorghum panicles enclosed with clear plastic bags. The panicles were cut from the plant and returned to the laboratory for examination and midge counts. Visual estimates of midge damage were made by rating damage to 10 panicles/plot, on a 1-9 scale where 1 = 0-10% and 9 = 81-90% kernel loss. Panicles were hand-harvested from selected 8.75 ft sections of row/plot and mechanically threshed. Data were statistically analyzed by ANOVA and REGWMRT.