Submitted to: North Central Weed Science Society US Proceedings
Publication Type: Abstract Only
Publication Acceptance Date: November 9, 2000
Publication Date: N/A
Technical Abstract: Alternative methods which minimize herbicide contamination of surface or ground water are needed to control weeds in no-till corn and soybeans. The objective of this research was to determine whether between-row mowing + band-applied herbicide could help reduce herbicide use, without sacrificing summer annual weed control or yield, in no-till soybean and field corn. Broadcast postemergence-applied glyphosate controlled winter annual weeds present shortly before or at planting for all treatments. In the between- row mowing weed management system, the band-applied soil residual herbicides imazaquin + alachlor in soybean or atrazine + alachlor in corn were applied shortly before or after planting followed by two or more between-row mowings to control summer annual weeds. Between-row mowing weeds very close to the soil surface two or more times killed or suppressed summer annual grass and broadleaf weeds, chiefly giant foxtail [Setaria faberii (L.) Beauv.], common cocklebur (Xanthium strumarium L.), and horseweed [Conyza canadensis (L.) Cronq.] when timed properly. Usually, weeds were first mowed when they were about 8-cm tall and again just before crop canopy closure. Shading after crop canopy closure contributed to subsequent weed suppression. The between-row mowing weed management system controlled weeds and increased yield in these no-till crops above a weedy check. It also controlled weeds and yielded as well as or better than broadcast-applied herbicide at the same rates. Soil residual herbicide use for controlling summer annual weeds was reduced 50% by banding because only 50% of the field area was sprayed.