FOLIAR INSECTICIDES FOR THE CONTROL OF BUDWORMS, HORNWORMS AND APHIDS ON FLUE-CURED TOBACCO, 2003

This experiment was conducted at the Virginia Tech Southern Piedmont Agricultural Research and Extension Center, Blackstone, VA to evaluate various foliar insecticides for the control of TBW and THW on flue-cured tobacco. Tobacco 'NC 297' was transplanted into experimental plots 4 × 40 ft (1 row × 22 plants) on 24 Jun. Rows were transplanted on 4-ft centers and plants were spaced at 22 inches within the row. Plots were separated by single untreated border rows. Fertilization, cultural practices and weed disease control conformed to recommendations of Virginia Cooperative Extension. Tobacco was artificially infested with one 3-d-old TBW/plant 1 d before application. Natural infestations of THW larvae were utilized in this trial. On 5 Aug, treatments were applied as foliar sprays using a CO2-pressurized backpack sprayer that delivered 22 gpa through TeeJet TX-10 nozzles (3 per row) at 50 psi. Temperatures ranged from 78 to 80°F and the wind speed was 4-6 mph. TBW and THW were counted on 20 plants/plot at 4 d before treatment and at 3, 8 and 17 DAT. GPA were counted on 4 upper leaves of 10 plants/plot at 8 and 17 DAT. Data were analyzed by ANOVA and significantly different means were separated by WD (k ratio = 100) (P ≤ 0.05). Before analysis, TBW and THW count data were transformed to square root (x + 0.5) and GPA counts were transformed to Log (x + 1). Actual means are presented in the tables.