by Meaghan Anderson, Field Agronomist, Dr. Bob Hartzler, Professor of Agronomy, Prashant Jha, Associate Professor, Integrated Crop Management News, and Iowa State University Extension and Outreach
The plentiful rain in September has provided ideal conditions for establishment of winter annual weeds, thus many no-till fields will have dense stands of these weeds going into winter (Fig. 1). The wetter springs we have encountered recently complicate getting spring burndown applications made in a timely matter.
Fall burndown applications are an option that may be beneficial in fields with a history of problems with winter annuals (e.g. horseweed/marestail, field pennycress, henbit). The advantages of fall applications include more consistent control since winter annuals are smaller, and there will be less weed biomass next spring that may interfere with planter operations. Consider the following before choosing this management option: