Efficacy of Selected Insecticides for Control of Soybean Insect Pest, 2016

On 26 Aug 2016, a foliar insecticide study was conducted in soybeans in Brooksville, MS. Plots were arranged in a randomized complete block with four replications. Plot size was four rows by 40 feet in length on 38-inch centers. Five insecticide treatments were evaluated against the untreated check (UTC) for the control of soybean looper (SBL), velvetbean caterpillar (VBC), green cloverworm (GCW), and green stink bug (GSB). Insecticides were applied with a tractor-mounted sprayer calibrated to deliver 10.0 gpa at 60 psi through TX-6 Hollow Cone nozzles (2 per row). Treatments were evaluated 3 and 7 d after treatment (DAT) for all pest except GSB, which was only evaluated 7 DAT. Plots were sampled by taking 25 sweeps per plot with a 15-inch-diameter sweep net and recording the number of SBL, VBC, GCW, and GSB per sample. Data were analyzed with ANOVA and means were separated using Fisher’s Protected LSD (P ≤ 0.05).

At 3 DAT, all insecticide treatments significantly lowered SBL, VBC, GCW below that of the untreated control (Table 1). At 7 DAT, all treatments lower VBC populations below the untreated control, while there were no significant differences in GCW counts. At the same sample timing, all treatments except Diamond alone had significantly lower SBL compared to the untreated control. For GSB at 7 DAT, all treatments significantly lowered populations below the untreated control except Belt.¹

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