Wild-proso millet is a warm-season annual grass that grows 1 to 6 feet tall. Not to be confused with the domestic proso millet that is cultivated as a feed grain and birdseed crop, wild-proso millet is often found as a weed in row crops throughout the US. It can quickly become economically damaging if left uncontrolled.
Seedlings of the wild-proso millet germinate between 50 and 113 degrees F. Wild-proso millet can be easily confused with corn seedlings, fall panicum, and witch grass. The millet can, however, be quickly identified by the seed husk which remains attached to the roots of the seedlings.
Leaves of the wild-proso millet alternate along the stem and are covered in small, stiff hairs. Blades are 1/2 to 3/4 inches wide. At the junction of the leaf and blade, there is a short, hairy outgrowth (ligule). The roots are shallow and fibrous. It also has a short growing season and needs little water.
The flowers of the wild-proso millet are at the end of each stem. They are arranged in a panicle which is broken up into spikelets 1/4 to 1/2 inches long, each with two flowers attached. The best way to tell wild-proso millet from domestic proso millet is to look at the seeds. Wild strains have dark brown or black seeds, while domestic strains have light brown or cream-colored seeds. The success of the wild-proso millet is owed to its proficiency in seed production and has been known to cause severe economic damage to certain fields.
Wild-proso millet is a very proficient reproducer, with little need for water as well as the tendency to grow well in cultivated fields and disturbed areas. These characteristics give it a keen edge in competing for nutrients and moisture in already stressed crop populations. After treatment, it is common to have a continuous problem as many seeds can remain dormant in the ground for some time.
Wild-proso millet is very sensitive to sunlight, and can be stifled by a pre-established cover crop such as winter wheat, alfalfa, barley, or oats. The regular mowing of alfalfa prevents seed production and can reduce millet seed reserves by 90 percent in four years. Mowing and tilling can be a greater contributer to spreading seeds if done at the improper time. The most effective method of control is to prevent the weed from getting started by cleaning equipment and buying clean seed.
Glyphosate is generally an effective heribicide when applied during early growth to plant bolting stages. It can also be effectively mixed with 2,4-D when combined with a non-ionic surfactant at .32 oz/gal of water and applied to early growth to plant bolting stages. Pendimethalin with a non-ionic surfactant at .32 oz/gal of water has also proven to be an effective herbicide when applied during early growth stages. The wild-proso millet plant is known to build some resistance to herbicides, so mechanical control/prevention is advised. Please contact your local weed specialist to learn what is most effective in your area and how to use it best. Always read and follow all label instructions.