Control of European Corn Borer Larvae and Effect on Spider Mites on Reproductive Stage Field Corn, 1995

Abstract

Abstract Various pesticides were applied to blister stage (R2 stage) field corn on 28 Aug near North Platte, NE. The treatments were applied with a CO2-charged backpack sprayer through 11002VS flat fan nozzles at 20 psi, in a total volume of 21 gpa. Each treatment was applied to 10 X 35 ft plots and replicated four times in a RCB design. One day prior to application, ~90 neonate ECB larvae were released on each of four plants in the center of each plot. The larvae were mixed in corn cob grit which was applied to the axils of three leaves of each plant. Artificially infested plants were collected 50 DAT, split from root to tassel and evaluated for the presence of ECB caused cavities, their total length and live ECB larvae. The size of TSM and BGM colonies were rated on the underside of the three lowest leaves of each 4 randomly selected plants from the middle of each plot 14 DAT. The rating scale was 0-5: 0 = no mites, 1 = individual mites (0-10 mites), 2 = small colonies (11-100 mites), 3 = large, individual colonies (101-300 mites), 4 = large connected colonies but not completely covering the underside of the leaf (301-1000 mites), 5 = colonies completely covering the underside of the leaf (1001-2000 mites).