Aphid Control on Dark Fire-Cured Tobacco, 1994

This experiment was conducted to evaluate various insecticides applied as foliar, transplant water (TPW) and soil treatments for tobacco aphid control on dark fire-cured tobacco. The experiment was conducted at the VPI & SU Southern Piedmont Agricultural Research and Extension Center, Blackstone, VA. Six treatments and an untreated control were established in a randomized complete block design with 4 replications. Plots, 4 × 40 ft (1 row × 24 plants), were separated by single untreated guard rows. Temik 15G was applied in a 14 inch band using a tractor mounted-Gandy granular applicator during bed formation and the band was immediately covered with 6 to 8 inches of soil on 17 May. Soil moisture was good for the Temik application. A carousel transplanter was used to transplant ‘VA 309’ dark firecured tobacco into the experimental plots in a Chesterfield-Mayodan-Bourne sandy loam soil on 18 May. The transplanter delivered the transplant water treatments (TPW) at 204-230 gal solution/acre in a continuous stream in the row. Except for insect control, Virginia Cooperative Extension recommendations were followed for production of dark fire-cured tobacco. Foliar applications of Orthene, Golden Leaf Tobacco Spray, and Dipel were made with a CO2-pressurized backpack sprayer that delivered 30 gal/acre through 3 TX-12 tips at 60 psi on 29 Jun. Aphid populations were estimated on the upper 4 leaves of 10 plants/plot about once a week from 5 to 9 wk after transplanting. Aphid damage was rated on a scale of 0 to 5 where 0 = no aphid injury or sooty mold and 5 = very severe injury as indicated by necrotic leaf tissue and sooty mold. Tobacco was stalk cut at maturity, cured, stripped, weighed, graded by a USDA/AMS inspector, and yield was calculated. Data were analyzed by ANOVA and significantly different means were separated by WD (K-ratio = 100). Aphid count data were transformed to Logl0(x + 1) before analysis.