Effective weed management is crucial for optimizing soybean yields and profitability; however, herbicide resistance poses a significant threat to efficient chemical weed control in soybeans. This proposed project directly addresses this issue through the development of new diagnostic tools, increased resistance screening capacity, and improved recommendations for resistance management. It represents a collaborative effort among some of the world's premier experts in herbicide resistance detection and management, spanning the eastern, southern, and northcentral U.S. soybean growing regions. Key objectives include developing rapid diagnostic tools for herbicide resistance detection, establishing diagnostic standards, discovering new herbicide resistance mechanisms for further diagnostic development, and translating these products directly to farmers. Funding will also provide training opportunities for six graduate students and two post-doctoral researchers, ensuring the development of the next generation of weed scientists. A major outcome will be the creation of a variety of diagnostic tools, which will be made available post-project through local universities across the soybean growing region. Ultimately, this collaborative approach aims to enhance communication and knowledge exchange among scientists, farmers, and agronomists, thereby strengthening the resilience of soybean production against herbicide resistance. If funds are awarded, they will be leveraged to obtain complementary support from private industry and the federal government to extend the proposed work. This project anticipates significant economic returns for soybean farmers, estimated at $87.5 million annually, by providing timely and effective weed resistance management solutions.

The proposed collaborative effort, spanning multiple soybean growing regions, seeks to address soybean growers’ needs by: i) Establishing a pipeline for identifying resistant weeds and setting diagnostic standards for confirming resistance, ii) Developing and deploying more rapid herbicide resistance diagnostics, iii) Discovering new herbicide resistance mechanisms for future diagnostic development, iv) Understanding how resistance manifests across pre- and post-emergence application timings, and v) Effectively disseminating information to soybean farmers and their advisors. Ultimately, this project aims to establish a broad and collaborative weed science workgroup to facilitate knowledge exchange and the development of decision support tools for local and regional weed management.

Objective 1) Develop standard greenhouse diagnostic protocols for resistance detection.
Objective 2) Create fast assays for known herbicide resistance mechanism detection.
Objective 3) Uncover novel resistance mechanisms for timely development of quick diagnostics.
Objective 4) Investigate resistance to pre- and post-applied herbicides in Amaranthus spp.
Objective 5) Disseminate findings, communicate with growers, and develop human capital.

Success will be evaluated by several metrics. First, PIs with extension appointments will incorporate results in their annual extension talks including explanations to growers that suspected resistant samples from soybean farms can be submitted for screening to either MSU or Miss State. The number of those talks, where they were located, and the number of attendants will be recorded. We will also include brief surveys at these meetings to check farmer understanding and willingness to use diagnostic services. Second, we will calculate how many samples are being submitted by soybean growers before, during, and after this project. As word spreads from extension talks about this project, we anticipate more growers being interested in testing. Furthermore, success in developing an herbicide resistance testing network for soybean growers will be measured by assessments conducted during the webinars and farmer panels at the North Central Weed Science Society (NCWSS), Northeastern Weed Science Society (NEWSS), and Southern Weed Science Society (SWSS) annual meetings. Third, we will work with our state soybean commodity groups to publish extension articles about this project and inform growers about herbicide resistance testing. We will measure growers understanding and awareness of testing in the first and last year of the project. Fourth, we will also keep track of the number of 1) protocols developed, 2) papers written, 3) extension articles written, and 4) students graduated that result from this effort. Finally, extension PIs will evaluate changes in growers’ response to putative resistance cases and the adoption of recommendations that are a result of discoveries from this project. All metrics will be collected and reported at the end of the third year of this project.

Updated August 1, 2025:
Our project, entitled “An integrated approach towards the detection, diagnosis, and response to emerging herbicide-resistant weeds in soybean” is off to a great start. We met as a group at Weed Science Society of America on February 25th, 2025 to begin planning our first steps and we chose the name “Hermon” (Herbicide resistance monitoring network) to talk about our project in brief.. Funds were received in March and subaward contracts and MTAs initiated immediately. Once funds were dispersed, the 11 PIs on the team were able to open positions at their respective universities and begin the hiring process to find personal to work on this project. Due to all of us working on the school year/student hiring cycle this meant most of us were hiring to start in the summer of fall of 2025. To date we have:
1. A research associate starting at Mississippi in September.
2. A research associate and student already working at Wisconsin
3. A master’s student at Texas
4. A post-doc and master’s student at Arkansas
5. A PhD student starting at Kansas state in September
6. A post-doc already started at Michigan
7. A post-doc already started at Pennsylvania

Those of us with extension appointments have been giving talks to soybean growers throughout the year, especially I the summer months about the importance of herbicide resistance testing and monitoring, and the importance of germplasm for Hermon. We expect several new populations to be received in late summer and early fall when weeds are putting out seeds. PIs Butts, Werle, Lancaster, and Sprague have especially been active in talks, hosting field days for soybean growers with herbicide demonstrations and appearing on local radio and on agriculture podcasts. Also in extension, PI Lancaster has started collecting interviews with the various PIs on this project as well as other knowledgeable weed scientists to be turned into short-form video essays about various important components of this project including a project overview, the importance of monitoring, the importance of getting your weeds tested, the importance of weed control and herbicide resistance management in general etc. We have developed a plan with USB, TakeAction, and GROW to publish these materials and amplify their impact.

In research we have made progress on several fronts. First we have begun collecting all the information about existing weed seed collections hosted at the various participating universities. This required a standardized database with inclusive fields to capture as much information about available germplasm as possible. With this we will begin sharing important seeds for bulk up and molecular investigation in the next steps of the project. We will also use this information to populate county-level maps with cases of confirmed and suspected herbicide resistance that will be made publicly available to growers. For this, we have begun meeting with the creators of EDDmaps, a powerful agriculture database that can generate up-to-date maps with ease. We are still working on what uploading our data will look like. We have supported their application for a symposium at the 2026 WSSA meeting which has been accepted and both PI Patterson and Lancaster will talk about the Hermon project and herbicide resistance monitoring.

PI Patterson and Tranel have also begun conversations with Corteva about the importance of the Enlist trait and monitoring and studying 2,4 D resistance in both Palmer and Waterhemp. While we have enough budget to tackle some of this resistance case, we have been talking to Corteva to leverage these funds and amplify our capacity to fully understand what drives 2,4D resistance in these species.

PIs Werle and Norsworthy have been working on extensive dose response greenhouse experiments looking at waterhemp resistance to PRE herbicides in Wisconsin and HPPD POST herbicides in Arkansas. The former being importance to protect PPO herbicides for Soybean and the later due to Bayer wanting to include HPPD herbicides in the upcoming HT4 soybeans. PIS Patterson, Werle, and Brunharo have also developing methodology to test for herbicide resistance in agar for Pre herbicides which will greatly accelerate and standardize pre-emergent resistance testing, PI Avila has been screening hundreds of grass weed samples (Goosegrass, Johnsongrass, and Lolium), developing standardized screening and populations for these important soybean weeds.

The remainder of the year will focus on germplasm sharing and bulk up, developing expanded collaborations both within and outside of Hermon, finalizing some of our extension materials, developing new assays for novel herbicide resistance cases, screening new cases of HR as they are discovered later this season, and a focus on methodology standardization.

Updated January 30, 2026:
Our project, entitled “An integrated approach towards the detection, diagnosis, and response to emerging herbicide-resistant weeds in soybean,” continues to make strong progress as we move beyond the initial startup phase and into full project implementation. Since our initial planning meeting at the Weed Science Society of America (WSSA) meeting in February 2025 and the receipt of funds in March, the Herbicide Resistance Monitoring Network (“HERMON”) has transitioned from planning and hiring to active research, extension, and coordination across institutions.

Over the past six months, all planned personnel hires have been completed and are now fully engaged in active research. Research associates, postdoctoral scholars, and graduate students are actively working at Mississippi, Wisconsin, Texas, Arkansas, Kansas State, Michigan, and Pennsylvania. With these positions now in place, laboratories and greenhouse facilities across the network are operating at capacity, allowing for coordinated screening, method development, and germplasm handling. This transition marks a major milestone, as the project is now executing its core scientific objectives rather than focusing on infrastructure and staffing.

Extension efforts have expanded substantially during this period. PIs with extension appointments have continued delivering presentations to soybean growers throughout the growing season, with a particular emphasis on late-summer and early-fall outreach as weed seed production approaches. These efforts have reinforced the importance of herbicide resistance testing, proactive monitoring, and the submission of germplasm to HERMON. PIs Patterson, Butts, Werle, Lancaster, and Sprague have remained especially active, hosting grower field days with herbicide demonstrations, participating in local radio programs, and appearing on agricultural podcasts. Patterson has appeared on the War With Weeds Podcast with PI Lancaster, several news articles have been written about the Hermon project, and short form video content produced. These activities have directly contributed to increased grower awareness and engagement, and we anticipate a notable increase in submitted weed populations during the upcoming seed collection window. PI Lancaster specifically has made significant progress on the development of short-form video content for extension and education. Recorded interviews with HERMON PIs and other leading weed scientists are now well underway and are being edited into concise video essays covering project overview, the value of resistance monitoring, the process and importance of weed testing, and best management practices for resistance mitigation. Coordination with USB, TakeAction, and GROW has advanced, and a clear dissemination plan is in place to publish and amplify these materials through established grower-facing platforms.
On the research side, substantial advances have been made. The standardized database for cataloging existing weed seed collections across participating institutions is now operational and populated with initial entries. This database captures detailed metadata on population origin, species, suspected or confirmed resistance traits, and available seed quantities. These efforts are enabling the first wave of coordinated germplasm sharing among institutions for seed increase, phenotypic screening, and molecular analyses. The database will also serve as the backbone for publicly accessible, county-level maps of confirmed and suspected herbicide resistance cases.

To support this mapping effort, PI Patterson and Lancaster have continued working closely with the EDDMaps development team to determine optimal data integration workflows. The first maps are now being produced with a fraction of the Hermon database for reference. While discussions are ongoing regarding data upload structure and data sharing permissions, progress has been made toward aligning HERMON datasets with EDDMaps standards. Importantly, a HERMON-focused symposium at the 2026 WSSA meeting has been accepted, where PIs Patterson and Lancaster will highlight the network’s approach to resistance monitoring and data-driven decision support.

Targeted research initiatives have also advanced. PIs Patterson and Tranel have continued discussions with Corteva to explore expanded collaboration on monitoring and mechanistic studies of 2,4-D resistance in Palmer amaranth and waterhemp, particularly in relation to the Enlist trait. Dozes of suspected 2,4-D resistant waterhemp and palmer plants have been studied and metabolism confirmed. Furthermore the exact metabolite has been identified that can be used as a resistance marker. These conversations aim to leverage existing HERMON resources with industry support to broaden the scope and depth of resistance characterization efforts.

Greenhouse and laboratory research is now producing actionable data. PIs Werle and Norsworthy have progressed extensive dose–response experiments evaluating waterhemp resistance to PRE herbicides in Wisconsin and POST HPPD herbicides in Arkansas. These efforts directly support stewardship of PPO herbicides in soybean systems and address emerging concerns related to potential HPPD use in forthcoming HT4 soybean technologies. Concurrently, PI Werle, has advanced the development of agar-based assays for PRE herbicide resistance testing, with preliminary protocols showing promise for accelerating and standardizing resistance diagnostics across laboratories. Agar based assays can now be confidently correlated with greenhouse dose. PI Avila has continued large-scale screening of grass weed populations, including goosegrass, johnsongrass, and Lolium spp., resulting in well-characterized populations that will serve as reference material for future soybean-focused resistance work.

Looking ahead, the remainder of the project year will emphasize coordinated germplasm sharing and seed increases, expanded collaborations both within and beyond the HERMON network, finalization and release of extension materials, and continued development and validation of novel resistance assays. Screening of newly submitted populations will intensify as seed collections increase, alongside a continued focus on methodological standardization to ensure consistency, reproducibility, and scalability across the network.

Key Accomplishments (Past 6 Months)
• Successfully transitioned HERMON from project initiation to full implementation, with nearly all planned research associates, postdoctoral scholars, and graduate students hired and actively working across seven participating institutions.
• Established and populated a standardized, network-wide database cataloging existing weed seed collections, enabling coordinated germplasm sharing, seed increase, and downstream phenotypic and molecular analyses.
• Launched coordinated greenhouse and laboratory research efforts, including dose–response studies on PRE and POST herbicide resistance in waterhemp and large-scale screening of key grass weed species relevant to soybean production.
• Made significant progress toward standardized resistance-testing methodologies, including development of agar-based assays for PRE herbicide resistance to accelerate and harmonize diagnostics across institutions.
• Expanded grower-focused extension and outreach efforts through field days, regional talks, radio programs, podcasts, and the initiation of short-form educational video content in partnership with USB, TakeAction, and GROW.
• Advanced data-integration planning with EDDMaps to support public, county-level mapping of confirmed and suspected herbicide resistance cases, and secured acceptance of a HERMON-focused symposium at the 2026 WSSA meeting.
• Initiated strategic discussions with industry partners to leverage HERMON resources and expand research capacity focused on emerging resistance traits, including 2,4-D resistance in Palmer amaranth and waterhemp.

There exists an urgent need for research that enables growers to swiftly diagnose herbicide resistance in their fields and access up-to-date information and recommendations for effectively managing emerging problems to maintain profitability and environmental sustainability in soybean production.