Tobacco Budworm and Hornworm Control in Flue-Cured Tobacco, 1996

Abstract

Abstract Full-Season Test. In Test 1, flue-cured tobacco, variety K-326, was transplanted on 10 Apr at the Georgia Coastal Plain Experiment Station Bowen Farm. Production practices were used according to Georgia Cooperative Extension Service guidelines and included a preplant tank mixture of Tillam and Devrinol for weed control, Ridomil for blue mold control, and Nemacur for nematode suppression. Fertilizer (6-6-18) was applied in a split application at a rate of 1000 lb/acre. Plots, two rows wide (44-inch row spacing) by 25 ft long, were arranged in a RCBD with 4 replications. Plots were separated on each side with a fallow border row and on each end with a 6-ft wide alley. On 31 May, 9 insecticide treatments were applied using a CO2 powered backpack sprayer equipped with three TX-12 nozzles directed over a single row, delivering 24.5 gpa at 40 psi. The number of live budworms and hornworms on all plants of both rows were recorded from each plot prior to treatment (pre-t) and 3,7,10 and 14 days after treatment (DAT). Plants 2-11 on the second row were harvested on 21 Jun and cured weights were determined by factoring out the moisture. All data were subjected to analysis of variance and the means were separated using DMRT. In Test 2, the K-326 tobacco used in Test 1 was striped of all leaves on 21 Jun, the stalks chopped down to a height of about 20 inches and allowed to regrow. This tobacco was side dressed with 16-0-0 at 100 lb/a after chopping. The plot size, randomization, and design remained the same as in trial 1. On 16 July, pre-treatment counts were made and the 9 treatments plus 2 TD 2344 treatments were applied on the regrowth tobacco. The number of live budworms and hornworms on all plants was recorded from each plot 3,7,10 and 15 DAT. The percent defoliation was visually determined for all plants in each plot on 25 and 31 Jul. All data were analyzed with an analysis of variance (P = 0.05).