Submitted to: Research Report North Central Weed Science Society United States
Publication Type: Other
Publication Acceptance Date: 12/18/1997
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: The purpose of this study was to evaluate various herbicide programs for weed control in glyphosate resistant corn. The study was established at the University of Illinois South Farm, Urbana. The soil was a Flanagan/Drummer silty-clay loam with a pH of 6.8 and 5.9% organic matter. Glyphosate resistant corn was planted 1.5 inches deep on April 24 in 30 inch rows. Treatments were arranged in randomized complete blocks with three replications of plots 7.5 by 25 feet. Herbicides were applied with a CO2 backpack sprayer delivering 20 gpa and equipped with 8003 flat fan nozzles for preemergence applications and 8002 flat fan nozzles for postemergence applications. Corn tolerance to glyphosate was excellent. Single applications of glyphosate provided excellent control of Pennsylvania smartweed and velvetleaf. However, control of giant foxtail, common lambsquarters, smooth pigweed, and tall morningglory ranged from 63 to 85%. Applying a sequential application of glyphosate increased control to 95% or greater of all above species. Applying MON12000 in combination with glyphosate increased broadleaf weed control while applying acetochlor or atrazine with glyphosate increased both broadleaf weed and giant foxtail control as compared to a single application of glyphosate applied alone. Weed control with glyphosate based programs was equal to standard herbicide programs.