arthropod management tests - issue

Foliar insecticide treatments of insecticides were evaluated for management of DBM in winter canola at Garden City, KS. Winter canola ‘KS4022’ was machine planted on 30 Aug 2010 at 8-inche row spacing using Farbro planter (5.0 lb seed/acre) in a field at the SW Research and Extension Center, Garden City, KS. Plots were 10 × 25 ft wide with 5-ft alleys between the plots. A pheromone trap was installed in the plot and maintained at the site beginning Sep 2010 through harvest in Jun 2011. The trapbottom was replaced weekly and DBM moths were recorded. The insecticides Capture, Coragen, and Lorsban were selected as representative of three different insecticide groups: pyrethroid, chlorantraniliprole (novel class of insecticide that targets ryanodine receptors), and organophosphate, for this efficacy trial. Chemical treatments were applied 12 Oct 2010 using CO2 backpack sprayer with two-nozzle handheld boom. The sprayer was calibrated to deliver 20 gpa @ 30 psi and 1.75 mph walking speed. Treatments were made when the pheromone traps indicated the DBM flight (of egg-laying stage) was declining and the DBM larvae were in the 2 or 3 instar. Diamondback moth larval infestation was recorded 3-days before application, then at weekly intervals after the application for eight weeks (WAT1 through WAT8). DBM larvae were evaluated by randomly pulling 10 plants from each plot and recording number of live larvae observed. The experiment was designed as a RCBD with four replicates. Data were analyzed with ANOVA, and treatmentmeans were separated using Fisher’s Protected LSD (P ≤ 0.05).