EFFICACY OF SELECTED INSECTICIDES FOR CONTROL OF SOYBEAN LOOPER AND CORN EARWORM IN SOYBEANS, 2011

On 9 August 2011, a foliar insecticide study was conducted in soybeans on a commercial field in Tchula, Mississippi. Soybeans were at approximately R5 stage of maturity. Plots were arranged in a randomized complete block with four replications. Plot size was 4 rows by 50 ft long on 38 in centers. Eight insecticides were evaluated against the untreated control (UTC) for control of soybean looper (SBL) and corn earworm (CEW). Insecticides were applied with a tractormounted sprayer calibrated to deliver 10.0 gpa at 60 psi through TX-6 Hollow Cone nozzles (2 per row). There are two sample dates following the application of treatments: 6 days after treatment (6 DAT) and 10 day after treatment (10 DAT). Plots were sampled by taking 25 sweeps per plot with a sweep net and recording the number of SBL and CEW larvae per 25-sweep sample. Data was analyzed with ANOVA and means were separated using Fisher’s Protected LSD (P≤0.05). All insecticide treatments on both sample dates had significantly fewer SBL larvae compared to the UTC, but were not different from one another. There were no significant differences among any of the insecticides evaluated and the UTC against CEW at either sample date.