Controlling Tobacco Insect Pests with Transplant and Foliar Insecticide Treatments, 1991

Abstract

Abstract Flue-cured tobacco, 'CV K-326', was transplanted on 12 Apr at the Coastal Plain Experiment Station Bowen Farm in Tift County, GA. Production practices were carried out according to Georgia Cooperative Extension Service recommendations. A pre-plant incorporated tank mix of the following was applied; Tillam and Devrinol for weed control, Ridomil for blue mold control, and Nemacur for nematode suppression. Fertilizer (6-6-18) was applied at a rate of 1000 lb/acre in a split application. Prior to planting, plots 4 rows wide (44 inch row spacing) by 20 ft long were arranged in a randomized complete block design with 4 replications. Six transplant insecticide treatments were applied at planting and included NTN 33893 in the transplant water, NTN 33893 as a foliar spray after transplant, Orthene in the transplant water, Orthene as a foliar spray after transplant, Temik in a 6-inch band to the side of the row and incorporated after transplant, and Furadan in an incorporated band after transplant. Also, Orthene was foliar-applied at 2 and 4 wk after transplant. The eighth treatment was an untreated control. Transplant water treatments were applied at a rate of 4 oz of form per plant. Foliar sprays were applied with a CO2-powered backpack sprayer equipped with 3, TX-12 nozzles directed over the row, delivering 22 gal of form/acre at 35 psi. Granular materials were applied with a Gandy applicator as sidedress applications in a 6-inch band to the right of the row and lightly incorporated. The center 2 rows of each plot were treated with an untreated border row on each side. All plots were separated on each end with an alley 4 ft wide. The number of live aphids and thrips was recorded on plants 2, 4, and 6 of row 2 of each plot 10, 21, 40, and 70 days after transplant. Also, the number of budworms and hornworms per 10 plants was recorded on these same sampling dates. Aphid damage ratings were taken on 27 Jun from each of the 10 plants in row 2 that were being used to determine yield estimates. Damage scores ranged from 0 (no visible aphid injury) to 10 (all upper leaves essentially covered with aphid injury, honeydew, and sooty mold). Also on 27 Jun each of the 10 plants were visually rated for percent defoliation. Between mid-Jun and late Jul each plot was harvested (4 primings) and cured. All data were subjected to ANOVA and Duncan's multiple range test (P = 0.05).