Claudio Rubione, University of Delaware and Mark VanGessel, Extension Weed Specialist; email@example.com
Most of the winter annuals in winter wheat have produced seeds and have senesced, but Italian ryegrass is one of the few species still present in fields. So it’s important to give consideration on how to prevent the spread of Italian ryegrass seeds. It is important to prevent their spread within the field or from field to field. Limiting seed spread in the field requires knowing what portions of the fields are infested. One method is to map the field before harvest. This can be done in advance of harvest, by marking infested areas in the field on a map and then planning a strategy to avoid contamination of the weed-free areas.
Harvest the weed-free portion of the fields first, leaving the weedy portions for last to prevent further spread of weed seeds. After harvesting the infested patches be sure to thoroughly clean the combine to remove as many weed seeds as possible (see video at: http://integratedweedmanagement.org/index.php/iwm-toolbox/prevention/equipment-maintenance/)
Summer annual weeds such as lambsquarters and pigweeds, may be present in wheat fields, but most of them have not begun to flower so there are very few viable seeds present.