ON-FARM EVALUATION OF MECHANICAL AND CHEMICAL WEED MANAGEMENT-PRACTICES IN CORN (ZEA-MAYS)

Combinations of rotary hoeing, cultivation, and band- or broadcast-app lied herbicides were compared for weed management in corn at 64 locati ons in Iowa from 1987 to 1991. Cultivation alone resulted in denser we ed populations than herbicide treatments at 41% of the locations; howe ver, corn yields were reduced at only 22% of the locations when weeds were controlled mechanically rather than with herbicides. Compared wit h broadcast applications, herbicides applied in a band resulted in inc reased weed populations at 8% of the locations; however, corn yields w ere reduced at only 1% of the locations.