Control of Insect Pests on Georgia Soybeans, 1997

The efficacy of seven selected insecticides for control of velvetbean cater-pillar and stink bugs was evaluated at the University of Georgia Coastal Plain Experiment Station, Tifton, GA. the insecticides were foliar applied on 18 Aug on ‘Davis’ soybeans planted on 4 Jun. Individual plots were 4 rows wide X 50 ft long with alleys 6 ft wide on each end and 2 border rows on each side, arranged in a RCBD with 4 replications. Each spray concentrate was applied with a CO2-powered backpack sprayer with 4, TX-12 nozzles on a 6 ft boom (2 nozzles per row) at 40 psi that delivered 19.5 gpa. Each plot was sampled prior to treatment and 3, 14, and 21 DAT (days after treatment) by taking a 20-sweep sample with a 15-inch diam net from a single row. Soybeans were in the R5 growth stage (pods filling with seeds) during the test period. On 2 Sep and 18 Sep, all plots were visually rated for % defoliation. At maturity, all plots were harvested with a plot combine and yields adjusted to 13% moisture. The data were subjected to ANOVA and Duncan’s multiple range test (P = 0.05).