Between-Row Mowing + Banded Herbicide to Control Annual Weeds and Reduce Herbicide Use in No-till Soybean (Glycine max) and Corn (Zea mays)1

Alternative methods are needed to control weeds in no-till corn and soybean which minimize herbicide contamination of surface or ground water. The objective of this research was to determine whether between-row (BR) mowing band-applied herbicide could help reduce herbicide use, without sacrificing summer annual weed control or yield, in no-till soybean and field corn. Glyphosate was applied shortly before or at planting to control emerged winter annual weeds in all treatments. In the BR 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. Annual weeds were first mowed when they were about 8 cm tall and again just before crop canopy closure. Between-row mowing weeds very close to the soil surface two or three times killed or suppressed summer annual grass and broadleaf weeds, chiefly giant foxtail, common cocklebur, and horseweed, when timed properly. The BR mowing weed management system increased yield above a weedy check in these no-till crops. It also controlled weeds and yielded as well as or better than broadcast-applied herbicide at the same rates. Use of soil residual herbicides to control summer annual weeds was reduced 50% by banding because only 50% of the field area was sprayed.Nomenclature: Alachlor, atrazine; glyphosate; imazaquin; common cocklebur, Xanthium strumarium L. # XANST; corn, Zea mays (L.) #3 ZEAMX, ‘Pioneer 3394’; giant foxtail, Setaria faberii (L.) Beauv. # SETFA; horseweed, Conyza canadensis (L.) Cronq # CONCA; soybean, Glycine max (L.) Merr. # GLYMA, ‘Pioneer 9461’.Additional index words: Band application, defoliation, mowing, mechanical weed control, no-till, no-tillage, tillage, topping.Abbreviations: DAP, days after planting; BR, between row.