Evaluation of Dipel Es for Management of Arthropods in Soybean, 1992

Abstract

Abstract The experiment was conducted at the Texas A&M University Agricultural Research and Extension Center, Beaumont. The experimental design was a randomized complete block with 4 treatments and 4 replications. Soil type was a Midland silty clay loam. Plot size was 60 ft × 6 rows (32-inch row spacing) with 2 buffer rows on either side of each plot. Plots were planted 22 May at about 10 seed/ft and treated with 2 pt Dual and % pt Scepter/acre in a finished spray volume of 20 gal/ acre. Seedlings emerged 26 May. Treatments as described in the tables were applied to the middle 2 rows of each designated plot on 5 Sep when soybeans were R5 and Lepidoptera defoliator populations were beginning to increase. Applications were made with a 4-nozzle hand-held boom sprayer equipped with 800067 tips and 50 mesh screens in a final spray volume of 20.8 gal/acre. The propellant was CO2 at 22 psi. Applications were made during calm conditions. Only 0.05 inches of rain fell within 1 wk after application. From application to the last sampling date (5 Sep-16 Oct), 2.27 inches of rain was recorded. Eight days before and 6, 12, 20, 28, 34, and 41 days after application, 9 ft of row in each plot were sampled with a vertical beat sheet. Samples were placed in plastic bags and refrigerated. At a later date, samples were inspected for arthropods. At maturity, the middle 2 rows of each plot were harvested with a small plot combine. Yields were adjusted to 13% moisture. Insect data were transformed using Vx + 0.5 and all data were analyzed using ANOVA and DMRT where appropriate.