Submitted to: Weed Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/30/2001
Publication Date: 5/1/2001
Citation: Donald, W.W., Kitchen, N.R., Sudduth, K.A. 2000. Between-row mowing + banded herbicide to control annual weeds and reduce herbicide use in no-till soybean (glycine max) and corn (zea mays). Weed Technology. 15:576-584.
Interpretive Summary: Because no-till farming methods keep crop residue on the soil surface, no-till helps prevent runoff and soil erosion on highly erodible sloping farmland. No-till farming methods substitute herbicides for tillage and cultivation to control weeds in corn and soybeans in the Midwest. But, the general public is concerned that currently used herbicides will contaminate esurface water and ground water. Methods are needed to reduce herbicide us in no-till farming systems and minimize the chance of water contamination by herbicides. Although not now used commercially, the between-row mowing weed management system may help achieve these goals in no-till. This system consists of four components: (1) a competitive crop, (2) post- emergence Roundup (glyphosate) broadcast applied shortly before or at planting to control emerged winter annual weeds, (3) band-applied soil- residual herbicide over crop rows at or after planting, and (4) two or more ebetween-row mowings close to the soil surface to control summer annual weeds. In this system, soil residual herbicide use for controlling summer annual weeds was reduced 50% by banding because only 50% of the field area was sprayed. The no-till between-row mowing weed management system controlled weeds and increased yield above a weedy check. It also controlled weeds and yielded as well as or better than broadcast-applied herbicide at the same rates. This alternative integrated weed management system has application in environmentally sensitive areas and can help reduce soil erosion or water contamination by either sediment or herbicides. Weed scientists and extension agents will be interested in this method.
Technical Abstract: Alternative methods are needed to control weeds in no-till corn and soybeans which minimize herbicide contamination of surface or ground water. 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 [Glycine max (L.) Merr.] and field corn [Zea mays (L.)]. 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.