Palmer amaranth, commonly known as pigweed, is one of the most common — and problematic — weeds in soybean crops across the southern United States. Because it is difficult to control, it is best to combat the weed before it emerges. The journal Weed Technology offers results of field tests of resistant Palmer amaranth in glyphosate-resistant soybean crops in Arkansas conducted over a two-year period. In this study, 250,000 glyphosate-resistant pigweed seeds were incorporated into the soil, and their emergence was evaluated five times during the growing season. Three farming practices were tested — deep tillage, planting a cover crop of rye and doublecropping a field with wheat and then soybeans in the same growing season.
This article appears in the October 2013 issue of Acres U.S.A.