Mississippi State University is among 10 land-grant universities helping lead a nationwide effort to combat pesticide-resistant weeds currently threatening soybean production.
Scientists from the school’s Mississippi Agricultural and Forestry Experiment Station are utilizing a $500,000 grant from the United Soybean Board, the Herbicide Resistance Monitoring Network, or HERMON, and other researchers to monitor weed resistance evolution, develop faster, more consistent diagnostic protocols, and improve region-specific weed-management strategies.
The group will aim to tackle the following major objectives: standardizing herbicide resistance diagnostics and investigating resistance to pre-emergent and post-emergent herbicides.
As part of the first objective, HERMON includes three regional hubs with specialized focuses. Mississippi State serves as the southern hub, concentrating on herbicide resistance in grasses common in southern soybean systems. Michigan State serves as the northern hub for broadleaf weed diagnostics, and the University of Arkansas specializes in Palmer amaranth. The three share the goal of developing consistent nationwide diagnostic methods.
Luis Avila and Paul Tseng, both scientists in Mississippi State’s Department of Plant and Soil Sciences, are leading the university’s contributions to the project.
“We are proud to contribute our experience in weed resistance diagnostics to this national collaboration,” Avila said. “As resistance issues intensify in the South, our team is working to advance diagnostics by testing grasses that are most problematic in southern soybean systems.”
Regarding weed response to both pre-emergent and post-emergent herbicides, past research has focused on post-emergent products, but officials report that HERMON will explore how weeds respond to pre-emergent herbicides and whether resistance to post-emergent herbicides also affects the performance of pre-emergent products with similar modes of action.
A pre-emergent herbicide is a type of weed killer that is applied before weed seeds germinate or sprout, preventing them from establishing themselves in the first place. Post-emergent herbicides are applied after weeds have already sprouted and are visible from the ground.
Researchers from Kansas State, Penn State, Purdue, Texas A&M, Wisconsin, Illinois, and Missouri are also participating in this campaign.
The United Soybean Board estimated that herbicide-resistant weeds cost U.S. soybean producers over $2 billion annually, highlighting the need for coordinated, research-driven solutions. The project also supports training for six graduate students and two postdoctoral researchers across the network who will be tasked with helping lead future weed resistance efforts.