Aaron Hager of the University of Illinois Extension Service cautions that wheat stubble fields in which no second crop is planted often become populated with summer annual (and sometimes perennial) weed species. No-tillers should not allow these plants to reach maturity and produce seed, he says.
Summer annual weed species that commonly populate wheat stubble fields include velvetleaf, common ragweed, pigweed and waterhemp, foxtails and fall panicum. These weeds can produce large amounts of seed if allowed to reach maturity and thus contribute to weed control issues in future growing seasons, he warns.
No-tillers can choose to control weeds in wheat stubble fields through mowing or herbicides. To achieve the highest level of success, these options should be implemented before any weeds begin to produce seed, Hager advises.
Mowing can effectively reduce the amount of weed seed produced by established broadleaf species. The shredder or sicklebar mower should be adjusted to cut as close to the soil surface as possible. Mowing might not completely eliminate weed seed production, because some seed could be produced from plants that regrow or from tillers present on grasses below the height of cutting. This method can help reduce seed production of simple perennials (such as common pokeweed), but it would do less to contain the expansion of perennial species that can spread by underground rootstocks (such as Canada thistle and johnsongrass).
Herbicides are available that can provide broad-spectrum control of weeds in wheat stubble fields. Glyphosate, 2,4-D and dicamba are examples that can be…