Tobacco Aphid Control on Flue-Cured Tobacco with Soil Insecticides Applied to Fumigated Soil, 1995

This experiment was conducted at the VPI & SU Southern Piedmont Agricultural Research and Extension Center, Blackstone, VA, to evaluate soil applied insecticides for TA control, and the resulting effects on value of flue-cured tobacco. Five treatments and an untreated control were arranged in a RCB design with 4 replications. Plots were 8 X 40 ft (2 rows X 24 plants). The entire test site was treated with Telone C-17 applied broadcast at 18 gpa on 12 Apr. Pretransplant soil treatments of the liquid formulations were applied broadcast with a CO2-pressurized, tractor-mounted boom sprayer that delivered at 32 gpa and 30 psi through 8003LP tips and immediately incorporated by double disking on 8 May. The Temik treatments were applied in a 14-inch band at bed formation using a tractor mounted-Gandy granular applicator and immediately covered with 6 inch of soil on 9 May. The soil was in excellent condition for both the pretransplant soil and bedding treatments. ‘K-326’ flue-cured tobacco was transplanted into experimental plots in a Chesterfield-Mayodan-Bourne sandy loam soil on 17 May. Virginia Cooperative Extension recommendations including disease and weed control, fertilization, topping, and sucker control were followed for production of the crop. Dipel 2X was applied to the entire test for tobacco hornworm control on 18 Jul. TA populations were estimated on the upper 4 leaves of 10 plants/plot about once a wk from 6 to 10 wk after transplanting. On 22 Aug, TA damage was rated on a scale of 0-10 where 0 = no damage and 10 = very severe injury. Tobacco was harvested as it ripened, weighted, graded by a USDA/AMS inspector, and yield and price were used to calculate value. Data were analyzed by ANOVA and significantly different means were separated by WD (K-ratio = 100). TA count data were transformed to Log10 (X+l) before analysis.