First-Generation European Corn Borer Efficacy Trials, 1988

Naturally infested whorl-stage yellow field corn was treated 14 Jun. Thirteen insecticides and 1 untreated control were arranged in a randomized complete block design with 4 replicates. All plots consisted of 4 contiguous rows, each 12 m long with 76-cm row spacing. Sprays were applied in water (20 gal/acre) with a CO2-powered system held above the canopy on a modified backpack frame. Each treated row received spray applied at 40 psi from 1 nozzle suspended over the row, perpendicular to the row (tip size HC-6). Granular products were applied manually with a funnel and band spreader system. Band spreaders were positioned approximately 5 cm above the whorl and distributed products over a 20-cm band. The 1988 growing season was characterized by severe drought and extreme temperatures. No rain fell for 2 wk after the treatments were applied. Twenty plants from the 2 center rows per plot were destroyed and examined from 8 through 14 Jul. Tunnels/20 plants, larvae/20 plants, and average percentage of plants infested with at least 1 tunnel/plant were recorded.