Reducing Weed Seed Production in Harvested Fields and Non-Cropped Areas

Mark VanGessel, Extension Weed Specialist;

Many annual and some perennial weeds are beginning to flower now, particularly those that emerged early in the summer. Removing now the flowering portions of the plant or seed heads will prevent most of these plants from producing mature seed. If these plants are mowed off, they are likely to regrow and eventually produce seed, but the quantity of seed produced will be dramatically reduced. Many of these fields will need at least one additional mowing to prevent seed production. However, delaying a mowing for a few weeks will allow a greater proportion of the developing seeds to mature and contribute to the seedbank. Another option is a herbicide treatment, however few herbicides will kill these large weeds. Glyphosate is one option, but be sure to match the herbicide rate with size and stage of the weeds.