Aphid Control in Georgia Flue-Cured Tobacco, 1991

Abstract

Abstract Flue-cured tobacco, 'Speight G-70', was transplanted on 29 Mar at the Coastal Plain Experiment Station in Tifton, GA. Production practices were carried out according to Georgia Cooperative Extension Service recommendations. A preplant incorporated tank mix of the following was applied: Tillam and Devrinol for weed control, Ridomil for blue mold control, Nemacur for nematode suppression, and Lorsban for wireworm and grub control. Fertilizer (6-6-18) was applied in a split application at a rate of 1000 lb/acre. Plots 4 rows wide (36- inch row spacing) by 20 ft long were arranged in a randomized complete block design with 4 replications of nine insecticide treatments (plus an untreated check). Treatments were applied on 13 May to control an aphid population that averaged around 500 per plant (4 upper leaves). The foliar sprays were applied with a CO2-powered backpack sprayer equipped with 3, TX-12 nozzles directed over a single row, delivering 27 gal/acre at 35 psi. Each plot was separated by an untreated border row and a 4 ft alley on each end. The number of live aphids on the 4 uppermost leaves was recorded on plants 2, 4, and 6 on row 2 of each plot prior to application and 3, 7, and 14 DAT. Aphid damage ratings also were taken on 3 Jun from each of the 8 plants in row 2 of each plot. Damage scores ranged from 0 (no visible aphid damage) to 10 (all upper leaves essentially covered with aphids, honeydew, and sooty mold). The number of thrips, flea beetles, hornworms, and budworms on plants 2, 4, and 6 also were recorded 14 DAT. On 12 Jun, the 8 plants on row 2 were harvested and yield estimates obtained. DATA were subjected to ANOVA and Duncan's multiple range test (P = 0.05).