Submitted to: Weed Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/30/2000
Publication Date: 5/1/2000
Citation: Donald, W.W. 2000 Between-row mowing + in-row banded herbicide for weed control in soybean (Glycine max). Weed Science. 48:487-500.
Interpretive Summary: Because the general public is concerned that currently used herbicides will contaminate surface water and ground water, alternative ways of controlling weeds are needed. Field crops, such as corn or soybeans, now receive the lion's share of herbicides in the Corn Belt. Although not now used commercially, selective mowing between crop rows + band-applied herbicide over crop rows may have site-specific potential as an alternative to eithe field cultivation or herbicides for controlling weeds in soybeans. When weeds are controlled within the soybean row with band-applied herbicide, cord or string mowing weeds close to the soil surface between soybean rows two to three times during the growing season allowed soybeans to yield as well as weed-free checks. 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. The method has a potentially large impact in reducing laborious weeding in row crops in third world countries where nonchemical methods of controlling weeds are used. The method also has potential in organic gardening and farming.
Technical Abstract: Most farmers now rely on herbicides and, to a lesser extent, cultivation for controlling weeds in soybean in the Midwest. But, the general public is concerned that currently used herbicides will contaminate surface water and ground water. Alternative ways are needed to control weeds in field crops which reduce or prevent herbicide contamination of surface and ground dwater. A integrated weed management system (IWMS), which consisted of band-applied herbicides over the soybean row plus two or more selective mowings between crop rows, was tested in soybean over six years in Missouri. Selectively mowing weeds close to the soil surface two or more times between crop rows with a mower killed or suppressed annual grass and broadleaf weeds, chiefly giant foxtail, common ragweed and waterhemp sp., if properly timed. Shading by crop canopy closure contributed to weed suppression in this IWMS. Soybean yield in the selective mowing-IWMS could dnot be distinguished from weeded check plots and was greater than the weed check plots. Herbicide mass applied per unit area was reduced by 50% by band application. The selective mowing-IWMS may have use in environmentally sensitive areas to help reduce soil erosion or water contamination by herbicides.