RESIDUAL EFFICACY OF FOLIAR INSECTICIDES FOR SOYBEAN LOOPER AND VELVETBEAN CATERPILLAR CONTROL, 2010

Foliar insecticide trials to evaluate control of soybean looper (SBL), Pseudoplusia includens (Walker) and velvetbean caterpillar (VBC), Anticarsia gemmatalis (Hübner) were conducted at the Dean Lee Research Station, LSU AgCenter, Alexandria, LA. Soybeans were planted at 8 seed per ft on 30 inch centers on 6 Jun in a Norwood silt loam. Plots were 4 rows wide by 25 ft in length and treatments were arranged in a RCBD with four replications. Insecticides were applied on 9 Aug using a CO2 backpack sprayer equipped with a T-jet nozzle, delivering 20 gpa at 40 psi. Weather conditions for the day of application were 0.00 inches of precipitation, wind speed of 4 mph, with a relative humidity of 94% and an air temperature of 100°F. Treatment efficacy against SBL and VBC was determined at 3, 7, 14, 21 and 28 DAT using a standard (15 inch diameter) sweep net to take 25 sweeps per plot and counting number of pests collected. Analysis of variance was performed following transformation of count data using log10(x+1). The level of significance was set at P= 0.05 and the REGWQ test was used to separate means.