COVER CROPS FOR HERBICIDE REPLACEMENT IN NO-TILLAGE CORN (ZEA-MAYS)

Weed control by rye, crimson clover, subterranean clover, and hairy ve tch cover crops was evaluated in no-tillage corn during 1992 and 1993 at two North Carolina locations. Weed biomass reduction was similar wi th rye, crimson clover, and subterranean clover treatments, ranging be tween 19 and 95% less biomass than a conventional tillage treatment wi thout cover. Weed biomass reduction using hairy vetch or no cover in a notillage system was similar averaging between 0 and 49%, but less th an other covers approximately 45 and 90 d after planting. Weed biomass was eliminated or nearly eliminated in all cover systems with PRE plu s POST herbicide treatments, Weed species present varied greatly betwe en years and locations, but were predominantly common lambsquarters, s mooth pigweed, redroot pigweed, and broadleaf signalgrass. Corn grain yield was greatest using PRE herbicides or PRE plus POST herbicides, a veraging between 16 to 100% greater than the nontreated control across all cover treatments depending on the year and location.