Ample soil moisture and warming temperatures are promoting rapid growth and development of many early-season weed species. Most weeds currently growing in fields emerged last fall and successfully overwintered (winter annuals, biennials or perennials), but several early-season summer annual species recently have emerged. Existing weed vegetation should be controlled before planting by utilizing tillage, herbicides, or a combination of tactics so the crop can become established under weed-free conditions.
Field scouting to identify the weeds present and their relative densities will provide the information needed to tailor a burndown herbicide program for any particular field. Many different weed species can be present in any particular field, and accurate identification sometimes can be challenging.
Check out the gallery for descriptions and color photographs of several weed species you may find in your fields at this time of year.
Source: University of Illinois Extension