Tobacco Insect Control with Insecticides Applied in the Transplant Water, 1994

Abstract

Abstract Various insecticides applied as soil, foliar and transplant water treatments were evaluated for TA and TFB control on flue-cured tobacco. Tests were conducted on a Chesterfield- Mayodan-Bourne sandy loam soil at the VPI & SU Southern Piedmont Agricultural Research and Extension Center, Blackstone, VA. Nine 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. The Lorsban 4E treatment was applied with a CO2-pressurized tractor sprayer that delivered 34 gal/acre at 30 psi through 8003LP tips on 3 May. The treatment was immediately incorporated by double disking. The soil temperature was 60°F, the ambient temperature was 64 to 66°F, and the weather was cloudy. The Temik treatment was applied in a 14 inch band using a tractor mounted-Gandy granular applicator and it was immediately covered with 6 inches of soil at bed formation on 11 May (soil temperature, 67°F; ambient temperature, 75°F; soil pH, 5.8; soil moisture, good). ‘K-326’ flue-cured tobacco was transplanted and the transplant water (TPW) treatments were applied in 215 gal solution/acre with a Holland plungertype transplanter on 12 May. The weather was sunny, and soil and ambient temperatures were 71"F and 77-80°F, respectively. Foliar applications of Orthene were applied on 22 Jun and 24 Jul with a CO2-pressurized backpack sprayer that delivered 30 gal/acre at 60 psi through 3 TX-12 nozzles/row. Tobacco production followed Virginia Cooperative Extension recommendations. TA were counted on the upper 4 leaves of 10 plants/plot about once a week from 1 to 13 wks after transplanting. TFB and TFB feeding holes in the most damaged leaf were counted on 10 plants/plot once a wk for 3 wks after transplanting. Tobacco was harvested as it ripened, weighed, graded by a USDA/AMS inspector, and yields and prices were 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.