E60

Abstract

The purpose of this study was to evaluate foliar insecticide treatments against caterpillar pests in conventional and Bt sweet corn at the Central Crops Research Station in Clayton, NC. The trial was arranged in a RCB with 8 treatments and four replicates. Plots were 3 rows by 35 ft long planted on 38 inch centers. Sweet corn seed was planted on 24 May 2011 using a single row push planter with 8 inch within row plant spacing. Foliar sprays were made every two days beginning at first silk and continuing until harvest. Insecticide applications were made on 8, 10, 12, 14, 16, 18, 20, 22, 24 Jul. All treatments were applied with a CO2 powered backpack sprayer with a four nozzle boom equipped with DC23 cores and D1 discs delivering 15 gpa at 40 psi. Sprays were directed at the silks with two drop nozzles on each side of the row. One ear was harvested from each of 10 consecutive plants in the second row of each plot on 25 Jul. Ears were transported to NCSU facilities in Raleigh, NC for damage evaluation. The number of corn earworm (CEW) damaged ears and the number of larvae per ear was recorded. The length of CEW damage was measured for each damaged ear. The number of European corn borer (ECB) larvae in each ear was recorded. Treatment means were analyzed using the General Linear Model Procedure in SAS (Version 9.1). When treatment differences were indicated by GLM, means were separated by LSD. All percent data were subjected to arcsine square root transformation prior to analysis. Untransformed data are presented.