Its rapid increase in density and distribution on cropland is associated with adoption of conservation tillage practices and continuous cropping. It causes the greatest problem in winter annual crops such as winter wheat and fall rye because the growth habits of the crop and weed are similar. Downy brome emerges over wide ranging soil temperature and moisture conditions and establishes well on the soil surface. It resumes growth in the spring at soil temperatures of 3 to 5 o C, thus attaining a competitive advantage over many other plant species. Downy brome heads out in late-May and produces mature seed by early July.
Seed has little dormancy and is capable of germinating that fall.
Most seed only will remain viable for 2 to 4 years. Downy brome emerging in the spring in winter wheat is much less competitive. If well controlled before seeding, downy brome is usually less of a problem in vigorous spring-seeded crops. Poor crop stands will allow downy brome to establish and be more competitive with crops. Control - Glyphosate is effective on small and large plants.