Harvest-Time Weed Seed Control
Research & development in Harvest Weed Seed Control is currently ongoing by members of this project team, and news on developments will be reported on this site – keep checking back!
Australian agronomists and producers are the pioneers of HWSC – watch this video for a 2-minute intro into HWSC.
Weeds that survive in-season control applications and mature through harvest-time need to be controlled so that they don’t set seed and increase the soil seed bank. However, herbicides are not designed to be effective against mature plants and their seeds. For this reason, mechanical techniques are looked to for late-season control. The spread of herbicide resistant weeds has raised particular concern over escaped weeds, spurring the development of innovative harvest-time control methods.
Harvest Weed Seed Control (HWSC) is a category of mechanical weed management techniques designed to prevent additions to the soil seed bank at harvest by capturing and destroying escaped weed seeds. HWSC also helps prevent the spread of weeds to other fields by destroying the seeds in-field. Because the majority of weed seeds are contained in the chaff portion of the crop, HWSC tactics specifically target destruction of the chaff. HWSC should not be thought of as weed control for the current season, but rather as an important management measure to decrease weed pressure for future seasons.
These technologies are relatively novel, and research and development is currently ongoing to evaluate their potential effectiveness in several US regions. Currently, HWSC is most widely adopted in Australia, where multiple herbicide resistant weeds has motivated their adoption by a large proportion of small grain producers. In Australia, a 2013 study found that various HWSC techniques (described below) destroyed between 75-99% of weed seeds at harvest (Walsh et al. 2013).