Aphid and Flea Beetle Control on Tobacco Grown in Fumigated Soil, 1994

Abstract

Abstract This experiment was conducted to evaluate various combinations of soil insecticides and foliar treatments for TA and TFB control and the resulting effects on the yield and price of fluecured tobacco grown in fumigated soil. Seven treatments and an untreated control were established in a randomized complete block design with 4 replications at the VPI & SU Southern Piedmont Agricultural Research and Extension Center, Blackstone, VA. Plots, 4 × 40 ft (2 rows × 24 plants), were separated by single border rows. The entire test site was fumigated for control of the tobacco cyst nematode, Globodera solanacearum. Telone C- 17 was applied broadcast at 19.1 gal/acre on 12 Apr. Most treatments of liquid formulations were applied broadcast with a CO2-pressurized, tractormounted boom sprayer that delivered at 30.4 gal/acre and 40 psi through 8003LP tips on 29 Apr. Treatments were immediately incorporated by double disking. The Temik treatments were applied in a 14 inch band using a tractor-mounted Gandy granular applicator and treatments were immediately covered with 6 inches of soil at bed formation on 17 May. The soil was in excellent condition for both the pretransplant soil and bedding treatments. Foliar applications of Orthene and Dipel were applied with a CO2-pressurized sprayer that delivered 30 gal/acre through 3 TX-12 nozzles at 60 psi. ‘K- 326’ flue-cured tobacco was transplanted into experimental plots in a Chesterfield-Mayodan-Bourne sandy loam soil on 18 May. Virginia Cooperative Extension recommendations were followed for production of the crop. TA populations were estimated on the upper 4 leaves of 10 plants/plot about once a week from 6 to 11 wks after transplanting. TFB and TFB feeding holes in the most damaged leaf were counted on 10 plants/plot during late May and early Jun. On 26 Aug, aphid damage was rated on a scale of 0 to 10 where 0 = no damage and 10 = very severe injury. Tobacco was harvested as it ripened, weighed, graded by a USDA/AMS inspector, and yield and price were calculated. Data were analyzed by ANOVA and significantly different means were separated by WD (K-ratio = 100). Aphid count data were transformed to Log,0(x + 1) before analysis.