Control in Field Corn, 1988

Abstract

Abstract A test was established at the Iowa State Research Farm at Ankeny to determine the effectiveness of preplanting incorporated insecticides. A randomized complete block design was used, and each treatment was replicated 4 times. Each plot was 1 row by 17.5 ft (1/1,000 acre). Each plot was surrounded by an aluminum barrier buried 6-8 inches and projecting above the soil 10-12 inches. Treatments were applied with a backpack sprayer calibrated to deliver 20 gal/acre at 40 psi. All treatments were incorporated 1-2 inches deep with a rotary tiller. Treatments were applied and incorporated 1 d prior to planting. Corn was planted 25 May with a John Deere 7100 Max-Emerge planter modified to plant 20 seeds/17.5 ft. Aluminum barriers were placed around each plot prior to plant emergence. Plots were infested 31 May with 20 third instars from a laboratory colony. From 1 to 10 Jun, cut plants and stand counts were determined. Cut plants were marked with an applicator stick so that they would not be counted as uncut plants in the event of plant regrowth. Data were transformed by arcsine V% + 1 for analysis.