Influence of select foliar insecticides on soybean looper management in soybeans I, 2022

On 19 August 2022, a soybean looper insecticide efficacy trial was conducted at Delta Research and Extension Center in Stoneville, Mississippi to evaluate the performance of 5 insecticides compared to an untreated check. Field studies were implemented as a randomized complete block with 4 replications. Field studies were implemented as a randomized complete block with 4 replications. All plots received applications with a MUDMASTER, 4WD Multi-Purpose Sprayer, (Bowman manufacturing, Newport, AR) equipped with a compressed air high clearance mounted multi-boom calibrated to deliver 10 gallons per acre at 50 PSI using TX-6 Hollow Cone nozzles (2 nozzles per row) (TeeJet Technologies, Glendale, IL). Soybean loopers were sampled 5, 10, 12, and 19 DAT by taking 25 sweeps with per plot with a 38.1-cm diameter sweep net. Percent defoliation in each plot was visually estimated at 19 DAT. Data were analyzed using ANOVA and means were separated using Fisher’s protected LSD (P ≤ 0.05).

At 5 DAT, all insecticides reduced soybean looper densities. Steward resulted in lower densities compared to all other treatments. Intrepid Edge reduced looper densities compared to Vantacor, Besiege, and Warrior plus Orthene. At 10 DAT, all treatments had lower soybean looper densities than the untreated control. Steward 1.25EC had the lowest soybean looper counts and was only similar to Intrepid Edge 3F. At the same sample date, Orthene 90S + Warrior IICS had similar densities to Besiege 1.25ZC and Vantacor 5SC. At 12 DAT, all treatments had lower soybean looper densities compared to the untreated check, except for Besiege 1.25ZC. Vantacor 5SC, Intrepid Edge 3F, and Steward 1.25EC had the lowest soybean looper numbers at this sample date. At 19 DAT, no treatments separated from the untreated check, Orthene 90S + Warrior II CS had the highest overall soybean looper densities and was only similar to Intrepid Edge 3F. In percent defoliation ratings, all treatments had less soybean looper feeding than the untreated check. Steward 1.25EC and Vantacor 5SC had the lowest overall feeding percentages and were similar to Besiege 1.25ZC and Intrepid Edge 3F (Table 1).¹

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