Efficacy of Biopesticides Against Aphids in Tobacco, 2017 Open Access

The efficacy of biologically derived insecticides against green peach aphids on tobacco was assessed at the Upper Coastal Plain Research Station (UCPRS) in Rocky Mount, NC. Six treatments, including an untreated check, were arranged in a randomized complete block (RCB) design with four replicates per treatment (Table 1). Untreated plants were planted on 21 Apr, and each 0.018 acre plot consisted of four, ca. 25 plant, rows. Starting 4 wk after transplant and continuing until topping, plots were checked weekly, stand counts were taken, and the number of plants infested with reproducing wingless aphids was counted in the middle two rows of each plot. These data were used to determine the percent of plants infested with aphids in each plot. Once reproducing aphids were detected on plants, treatments were applied weekly until topping using a CO₂-powered backpack sprayer fitted with a TG2 or TG3 solid cone nozzle at 52 psi. Treatments were applied on 9 Jun, 15 Jun, and 19 Jun. For the first two applications, 15-gpa spray volume was used, and 30 gpa used for the 19 Jun applications. Plants were topped on 3 July. Data were analyzed in SAS v. 9.4 via proc mixed with treatment, date, and treatment × date interactions as fixed effects and replicate nested in treatment as a random effect. If significant treatment × date interactions occurred, means were compared within each date. Means were separated by Fisher’s protected LSD (α = 0.05).

No significant interaction between insecticide treatment and application date was observed, so season-long treatment means are presented in Table 1. None of the insecticides reduced aphid densities compared with the untreated check. This research was supported by industry gifts of product and research funding.