DOSE-RESPONSES OF WEEDS AND WINTER-WHEAT (TRITICUM-AESTIVUM) TO MON-37500

Greenhouse studies determined the dose-responses of cheat, downy brome , Japanese brome, jointed goatgrass, and winter wheat to preplant-inco rporated MON 37500 and its residual effects on kochia. Concentrations of MON 37500 up to 60 ppbw did not affect winter wheat, MON 37500 did not prevent weed emergence, but increasingly inhibited weed growth as the dose was increased up to about 20 ppbw. GR(50) values were 16, 16, 11, and 31 ppbw for cheat, downy brome, Japanese brome, and jointed g oatgrass, respectively. Japanese brome was more susceptible than cheat or downy brome, and jointed goatgrass tolerated two to three times mo re MON 37500 than the Bromus species. Plant dry weights of kochia seed ed after removal of the winter annual grasses decreased with increasin g initial MON 37500 concentrations up to 20 ppbw, Kochia density was i nfluenced by which winter annual grass was grown previously.