Biology and management Wild proso millet mimics sweet corn growth. Seeds mature before corn harvest, facilitating spread with machinery. Seed longevity in soil, however, is relatively short (3 to 5 years). Rotating to grass seed or summer annual broadleaf crops helps deplete the seedbank if wild proso millet is not allowed to produce seed. Wild proso millet seedlings emerge erratically throughout the season because of inherent seed dormancy, which is strongest for black-seed types. Cultivation that brings new seeds to the surface, or irrigation and rain, often causes a new crop of weed seedlings to emerge.
Selective herbicides that suppress or control wild proso millet include S-metolachlor, dimethenamid-P, nicosulfuron, and topramezone, tolpyralate and tembotrione. In fields with a very high density of wild proso millet seeds, control efforts may need a preplant herbicide such as dimethenamid-P + S-metolachlor, followed by a preemergence herbicide, followed by cultivation(s) or another postemergence herbicide. Both topramezone and tembotrione provide good control of wild proso millet up to 6 inches tall, but do not provide residual control.