Efficacy Foliar Applied Insecticides on Tobacco Budworm in Flue-Cured Tobacco, 2020 Open Access

The efficacy of registered insecticides against tobacco budworm was assessed at the Upper Coastal Plain Research Station (UCPRS) in Rocky Mount, NC. At this location, five treatments, including an untreated check, were arranged in an RCB design with four replicates per treatment (Table 1). On 27 Apr 2020 ca. 100 plants were transplanted into 0.018-acre plots. Each plot consisted of four rows (48 in centers), 50-ft in length. Foliar treatments were applied using a CO₂ pressurized backpack sprayer fitted with a single TG2 solid cone nozzle calibrated to apply 15 gal/acre spray volume at 52 psi pressure to the middle two rows. The outer rows of each plot were left untreated to minimize drift. Applications were made at TBW threshold (10% of plants infested with ≥1 TBW) on 22 Jun. Each plant in the middle two rows of a plot was examined for presence of TBW once per week. TBW abundance was recorded prior to application on 22 Jun and then one and two WAT (29 Jun, 6 Jul, respectively). TBW abundance was analyzed in R v. 3.5.3 using LMER with Treatment as a fixed effect and replicate as a random effect. Means were separated by Fisher’s protected LSD (α = 0.05).

No difference was observed in the pretreatment counts on 22 Jun (Table 1). At one WAT, all materials reduced TBW counts compared to the untreated check. Denin and Exirel showed continued efficacy at two WAT compared to the untreated check. At two WAT, there was no difference between the Spear-Lep + Leprotect treatment and the untreated check. While Steward and Spear-Lep + Leprotect were not significantly different at two WAT, Steward did differ from the untreated check.¹

Footnotes