COLUMBIA, Mo. – Two words may best describe waterhemp: prolific and smart.

University of Missouri Extension weed scientist Kevin Bradley and his team will share the latest research on treating waterhemp with chemical and nonchemical means at the 2025 Crop and Pest Management Field Day on July 10 at Bradford Research Farm in Columbia.

Its ability to adapt has made waterhemp the state’s No. 1 weed foe since the 1990s. In 2004, Bradley confirmed the first official case of glyphosate resistance in the world.

Since then, Bradley and his group have confirmed multiple resistances to herbicides with different modes of action in waterhemp populations throughout the state.

Waterhemp grows quickly – up to an inch per day – and can reach up to 6 feet in height. Its seeds can germinate later in the season than many other weed species. This allows it to escape many preemergence herbicides and often enables it to flourish after postemergence applications of nonresidual herbicides like glyphosate and glufosinate. Its seeds can persist in the soil for as long as four years with 95% of the seed remaining viable.

For more information on waterhemp, the MU Extension publication “Management of Glyphosate-Resistant Waterhemp in Corn and Soybean” is available for free download.

Details and registration. For more information, contact Heather Bowden at nicholshn@missouri.edu or 573-882-4303.

MU Bradford Research and Extension Center is 8 miles east of Columbia at 4968 Rangeline Road. Registration begins at 8 a.m.

Continuing education units are available for certified crop advisers.