Two insecticides were evaluated for control of sugarcane aphid ingrain sorghum at the Research and Education Center at Milan, TN.One treatment included an insecticide tank mixed with a fungicide.Grain sorghum was planted on 3 Jun. The test was arranged in anRCB design with four replicates. Individual plots were 12.5 × 30 ft.Foliar application was made on 1 Aug during early flowering with ahigh clearance sprayer calibrated to deliver 9.3 GPA at 40 PSI with8001 flat fan nozzles. The plots were sampled by visually countingthe number of aphids on the underside of randomly selected sorghumleaves from the center rows of plots. Insect control was evaluated 6Aug, 5 days after treatment (5 DAT), 12 Aug (11 DAT), 16 Aug (15DAT), and 19 Aug (18 DAT). Aphids on ten flag leaves were counted5, 11, and 15 DAT. Five flag leaves and five leaves in the middleportion of the canopy were sampled 18 DAT and the average, totalnumber of aphids from flag and middle-canopy leaves are presentedbelow. Fungicide efficacy was rated on 30 Aug by visually estimatingthe percent area of leaves with symptomology of disease, primarilyconsisting of target spot and anthracnose. Yield data were collected20 Nov by harvesting two center rows of each plot with a plot combine.Data were subjected to ANOVA, and means were separatedusing a protected least significant difference (LSD).
展开▼
