E12

Abstract

The objective of this study was to evaluate the efficacy of several soil systemic insecticides applied as bed-top banded spray applications against sweetpotato whitefly. Broccoli ‘Emerald Crown’ was direct seeded into double row beds on 42 inch centers on 25 Aug, 2011. Plots were one bed wide by 35 ft long and bordered by one untreated bed. Stand establishment was achieved using overhead sprinkler irrigation, and irrigated with furrow irrigation thereafter. Four replications of each treatment were arranged in a RCB design. Product formulations and rates for each spray program are provided in the table. The soil insecticides were applied as a surface-band treatment using a single-row boom equipped with 1 flat fan nozzle (8004VS) oriented parallel with the seed line and calibrated to deliver 25 gallons of spray per acre at 40 psi. A 2-3 inch spray band was placed directly over each seed line immediately following planting. The insecticides were incorporated into the soil using sprinkler irrigation that is commonly employed for seed germination during stand establishment. Evaluations of SWF control was estimated by counting the number of total nymphs on two, 2-cm disk sections taken from 2 consecutive basal leaves collected from each of 5 plants per replicate at various days after plant emergence (DAPE). SWF nymph densities on each leaf disk were estimated under magnification in the laboratory. Because of heterogeneity of mean variances, data were log transform (mean+0.5) and subjected to ANOVA; means were separated using Fprotected LSD (P ≤ 0.05). Actual non-transformed means are presented in the table.