Annual/Termination Reports:

[03/25/2025] [08/07/2026]

Report Information

Participants

Aynardi, Brian (baynardi@pbigordon.com) - PBI Gordon; Banyai, Zoltan (zbanyai@wisc.edu) - University of Wisconsin - Madison; Beirn, Lisa (lisa.beirn@syngenta.com) - Syngenta; Blanton, John (john.blanton@sdstate.edu) - SD State; Butler, Lee (elbutler@ncsu.edu) - NC State; Chou, Ming-Yi (mc2741@sebs.rutgers.edu) - Rutgers University; Crowell, Chase (chase.crowell@uconn.edu) - UConn; Dant, Luke (lukas.dant@syngenta.com) - Syngenta; Dean, Dylan (djdean3@ncsu.edu) - NC State; Dykema, Nancy (dykema@msu.edu) - Michigan State; Fidanza, Mike (maf100@psu.edu) - Penn State; Fletcher, Rick (rick.fletcher@nufarm.com) - Nufarm; Fraser, Melodee (mfraser@pureseed.com) - Pure Seed; Freund, Daniel (drfreund@ncsu.edu) - NC State; Galle, Glenn (glenn.galle@syngenta.com) - Syngenta; Giese, Matt (matt.giese@syngenta.com) - Syngenta; Gregos, Jeff (jeffgregos@walkersupplyinc.com) - Walker Supply Inc; Hensler, Kevin (khensler@vt.edu) - Virginia Tech; Hockemeyer, Kurt (hockemeyer@wisc.edu) - University of Wisconsin - Madison; Horvath, Brandon (bhorvath@utk.edu) - Tennessee; Inguagiato, John (john.inguagiato@uconn.edu) - Uconn; Kaminski, John (kaminski@psu.edu) - Penn St; Kerns, Jim (jpkerns@ncsu.edu) - NC State; Koch, Paul (plkoch@wisc.edu) - University of Wisconsin - Madison; Latin, Rick (rlatin@purdue.edu) - Purdue University; Letot, Carson (letotc@sandhills.edu) - USGA; Lookabaugh, Emma (emma.lookabaugh@basf.com) - BASF; McCall, Dave (dsmccall@vt.edu) - Virginia Tech; Miele, Kevin (kmiele@pbigordon.com) - PBI Gordon; Miller, Lee (turfpath@purdue.edu) - Purdue University; Miller, Kyle (kyle.miller@basf.com) - BASF; Murphy, Jim (jamurphy@njaes.rutgers.edu) - Rutgers University; O'Brien Daniel (dobrien@usga.org) - USGA; Petrovsky, John (jpetrovsky@usga.org) - USGA; Rioux, Renee (renee.rioux@basf.com) - BASF; Roberson, Travis (travis.roberson@syngenta.com) - Syngenta; Russell, Travis (travis.russell@envu.com) - Envu; Ruwona, Justice (jruwona@purdue.edu) - Purdue University; Stacy, Trevor (trevor.stacy@basf.com) - BASF; Thompson, Cole (cthompson@usga.org) - USGA; Tredway, Lane (lane.tredway@syngenta.com) - Syngenta; Wu, Shaohui (wu.6229@osu.edu) - Ohio State; Zhang, Pingyuan (bay.zhang@envu.com) - Envu; Batchen, Brandon (bmatchen@rpswi.com) - Reliable Properties; Bonos, Stacy (bonos@sebs.rutgers.edu) - Rutgers University; Brilman, Leah (lbrilman@dlfna.com) - DLF; Britton, Barry (bbb@barrybbritton.com) - Britton Consulting; Burgess, Pat (patrick.burgess@envu.com) - Envu; Castillo-Russi Juan (jcastillo@barenbrug.nl) - Barenbrug; Clarke, Bruce (bruce.clarke@rutgers.edu) - Rutgers University; Coffelt, Mark (mark.coffelt@syngenta.com) - Syngenta; Espevig, Tatsiana (Tatsiana.Espevig@nibio.no) - NIBIO; Fenn, Geoff (geoff.fenn@originamenity.com) - Origin Amenity; Giordano, Paul (pgiordano@Harrells.com) - Harrells; Hurley, Rich (hurlrich1987@gmail.com) - Independent breeder; Kenna, Mike (mkdmk56@gmail.com) - USGA Retired; Kennelly, Megan (kennelly@ksu.edu) - Kansas State; Kumar Thera, Uday (Uthera@umd.edu) - University of Maryland; Larsen, Mads (mads.wadum.larsen@dlf.com) - DLF; Lycan, Darren (darren.lycan@syngenta.com) - Syngenta; Nangle, Ed (nangle.1@osu.edu) - Ohio State; Praemasing, Wolfgang (w.praemassing@hs-osnabrueck.de) - Osnabrueck; Roberts, Joe (jar7@clemson.edu) - Clemson; Spring, Christian (Christian.Spring@strigroup.com) - STRI; Thach, Tine (tine.thach@dlf.com) - DLF; Townsend, Ron (Ron.Townsend@syngenta.com) - Syngenta; van 't Klooster, Gerard (gerardvantklooster@turfgrass-consultancy.nl) - Turfgrass Consultancy (NL); Vosters, Bente (bvosters@barenbrug.nl) - Barenbrug (NL); Vroegop, Irene (i.vroegop@sglsystem.com) - SGL System (NL); Wolleswinkel, Arthur (info@grass2value.nl) - Grass 2 value (NL)

Brief Summary of Minutes

Accomplishments

<p><strong>Short-term outcomes:</strong> This is the first year of the renewed NC1208 and the 6^th year of the project overall. This year&rsquo;s annual meeting was expanded to serve as the first &lsquo;Dollar Spot Research Conference.&rsquo; This 2-day event was open to both public and private researchers and practitioners interested in dollar spot management. The primary goal was to bring together different people involved in dollar spot management to assess where we are as an industry, identify key knowledge gaps, and to address collaborative research projects to address those knowledge gaps. The conference was successful and included many people remotely attending the conference from Europe, where dollar spot has become an important problem. In addition to the conference, the NC1208 team is conducting multiple collaborative research projects. New projects ideas were also discussed and are outlined below. Lee Miller from Purdue University took over as the chair of NC1208 at the conclusion of the research conference.&nbsp;</p><br /> <p><strong>Outputs:</strong> The first NC1208-led project titled &lsquo;Efficacy of integrated cultural practices for dollar spot disease management on creeping bentgrass and bermudagrass&rsquo; was published in the International Turfgrass Research Journal (<a href="https://doi.org/10.1002/its2.188">https://doi.org/10.1002/its2.188</a>). The team ended the &lsquo;host resistance&rsquo; project and will now focus on data analysis and publication in a peer-reviewed journal. We hope this publication will be ready for submission by the end of 2025. In addition, assistant professors Quincy Law (Iowa State) and Tyler Carr (Ohio State) have agreed to lead the publication of the bentgrass survey results.&nbsp;</p><br /> <p><strong>Activities:</strong></p><br /> <ul><br /> <li>Dollar spot cultural practices publication<br /> <ul><br /> <li>This manuscript was titled &lsquo;Efficacy of integrated cultural practices for dollar spot disease management on creeping bentgrass and bermudagrass&rsquo; and was published in the International Turfgrass Research Journal (<a href="https://doi.org/10.1002/its2.188">https://doi.org/10.1002/its2.188</a>). A poster summarizing this project will be presented at the 2025 International Turfgrass Research Conference.</li><br /> </ul><br /> </li><br /> <li>Bentgrass cultivar survey publication<br /> <ul><br /> <li>This project was completed in the spring of 2022. Numerous interesting results were obtained from the survey results and assistant professors Quincy Law (Iowa State) and Tyler Carr (Ohio State) have agreed to lead the publication of the bentgrass survey results. Journal of Extension, HortTechnology, and other journals were mentioned as possible hosts for this potential publication.</li><br /> </ul><br /> </li><br /> <li>Dollar spot host resistance<br /> <ul><br /> <li>This project was seeded in the summer of 2021 at 7 different locations. Many sites had very high dollar spot pressure in 2022 and saw limited treatment differences within cultivar, though it was clear that Coho had superior dollar spot resistance compared to Shark and Penncross. Paul Koch presented data from 2023 and many locations, notably Michigan State and Wisconsin, had very low dollar spot levels and saw no statistical treatment difference. Results from Rutgers demonstrated that Coho has superior dollar spot resistance compared to Shark and Penncross. Within each cultivar, treatments where the dew was removed had modest reductions in disease compared to where the dew was not removed. The results from Kansas State were similar to Rutgers, except that Shark demonstrated modest resistance compared to Penncross. There was no indication at any site of a dollar spot reduction associated with biocontrol usage. This study has now ended and the data will begin to be analyzed for manuscript preparation.</li><br /> </ul><br /> </li><br /> <li>Dollar spot model on improved cultivars<br /> <ul><br /> <li>This was a new project initiated in 2023 and continued for a second year in 2024. Participating institutions were Wisconsin, Rutgers, Kansas State, Penn State, UMass, Michigan State, and Maryland. The objective was to determine Smith-Kerns Dollar Spot model thresholds for cultivars with varying resistance to dollar spot. Paul presented results from a few locations and the results were quite consistent in demonstrating that the spray threshold can be increased to 60% or higher on a highly resistant cultivar like Coho. The project will continue in 2025 with modfied thresholds for each cultivar.</li><br /> </ul><br /> </li><br /> <li>Interseeding resistant bentgrass cultivars<br /> <ul><br /> <li>Miller&rsquo;s graduate student Justice Ruwana provided an update to the group on this project. The objective is to identify and assess bentgrass conversion strategies and document potential fungicide savings following conversion to a more modern bentgrass. Purdue, Penn State, and Wisconsin are participating in this project. All three locations initiated the project with bentgrass interseeding and chemical applications in the summer of 2023. Tissue samples were collected and sent to Scott Warnke with the USDA to determine the genetic makeup of the host plants prior to the interseeding process. The project continued in 2024 and focused on dollar spot and annual bluegrass differences observed between the treatments and the number of fungicide applications needed for acceptable dollar spot suppression. An additional tissue collection will be performed and submitted to Scott Warnke for analysis of how much of the new bentgrass has actually established itself in the plots.&nbsp;</li><br /> </ul><br /> </li><br /> </ul><br /> <p><strong>New project ideas</strong></p><br /> <ul><br /> <li>Robotic mowers for dollar spot control.</li><br /> <li>Additional sample sites to assess dollar spot suppressive soils</li><br /> <li>Low fungicide rates for dollar spot control</li><br /> </ul>

Publications

<p>The first NC1208-led project titled &lsquo;Efficacy of integrated cultural practices for dollar spot disease management on creeping bentgrass and bermudagrass&rsquo; was published in the International Turfgrass Research Journal (<a href="https://doi.org/10.1002/its2.188">https://doi.org/10.1002/its2.188</a>). The team ended the &lsquo;host resistance&rsquo; project and will now focus on data analysis and publication in a peer-reviewed journal. We hope this publication will be ready for submission by the end of 2025. In addition, assistant professors Quincy Law (Iowa State) and Tyler Carr (Ohio State) have agreed to lead the publication of the bentgrass survey results.</p><br /> <p>&nbsp;</p>

Impact Statements

1. Dew removal can reduce dollar spot severity relative to a non-treated control by approximately 25% when done prior to 7:30 AM.
2. Stacking multiple cultural practices (i.e. dew removal + nitrogen) doesn’t appear to suppress dollar spot more than the individual practices do.
3. Disease-resistant cultivars can provide extremely effective suppression of dollar spot development.
4. Biocontrol products failed to provide meaningful dollar spot suppression even on more resistant cultivars.
5. Smith-Kerns Dollar Spot Model thresholds can be significantly increased on disease-resistant cultivars. Further work will refine just how much they can be increased by.
6. Most superintendents don’t alter their disease management programs after seeding disease resistant cultivars. This is an opportunity for us as researchers and extension specialists to develop improved disease best management practices specifically for disease resistant cultivars.

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Report Information

Participants

Miller, Lee - U of Wisconsin; Ming Yi Chou - Rutgers; Wang, Ruying (Wrennie) - Michigan State; Kitchin, Elisabeth - Virginia Tech; Kreinberg, Sam - Virginia Tech; Boos, Meredith - U of Wisconsin; Cuenca Proano, Fernanda - U of Wisconsin; Hockemeyer, Kurt - U of Wisconsin; Bender, Amanda - U of Wisconsin; Soldat, Doug - U of Wisconsin; Kennelly, Megan - Kansas State; Bremer, Dale - Kansas State; Murphy, James - Rutgers; Clarke, Bruce - Rutgers; Wu, Shaohui - Ohio State; Thompson, Cole - United States Golf Association; Brilman, Leah - DLF Pickseed; Gregos, Jeff - Walker Supply; Warnke, Scott - USDA ARS (retired); Gaussoin, Roch - Nebraska; Dykema, Nancy - Michigan State; Bahri, Bochra - Georgia; sa82242@uga.edu - Georgia; Jung, Geunwha - Massachusetts; Ghimire, Krishna - Purdue; Ruwona, Justice - Purdue; Espevig, Tatsiana - NIBIO - Norway; Hamilton, Christina - NIMSS

Brief Summary of Minutes

Accomplishments

<p style="font-weight: 400;"><strong>Short-term Outcomes</strong></p><br /> <p style="font-weight: 400;">This is the second year of the renewed NC1208 and the 7th year of the project overall. Collaborative research is focused on several strategic initiatives as described below that will increase the adoption of technology (i.e. host resistance), reduce the cost and increase the efficacy of dollar spot control, and reduce the impact of fungicide applications on the environment. The ability to utilize resistant cultivars and increased spray thresholds provides managers with more flexible, cost-effective disease management strategies, reducing their reliance on frequent fungicide applications. The adoption of autonomous mowing technologies, alternative practices such as leaf pH manipulation and biological controls can offer a method reducing dollar spot and labor costs. By facilitating a reduction in fungicide usage and promoting the use of biological and mechanical controls, this research contributes to decreased chemical exposure in the environment and promotes the long-term health of the soil microbiome.</p><br /> <ul style="font-weight: 400;"><br /> <li>Improved Management Models:&nbsp;Research into improved cultivars has successfully demonstrated that spray thresholds can be significantly increased&mdash;to 60% or higher&mdash;on highly resistant cultivars. Integration of host resistance with dollar spot prediction models, autonomous mowing, nitrogen scheduling and other management practices that can build a framework for disease management with higher reductions in fungicide use.</li><br /> <li>Autonomous Mowing &amp; Disease Mitigation:&nbsp;Preliminary investigations into autonomous mowing have shown significant potential for disease management. Early data suggests that consistent maintenance schedules provided by autonomous robots can help manage disease levels and improve turf quality. Furthermore, the integration of autonomous mowers with dew-removal capabilities can reduce dollar spot severity compared to non-treated controls.</li><br /> <li>Technological Advancement in Disease Assessment:&nbsp;The development of the "Dollarspotter" program, a machine learning model designed to identify and quantify dollar spot outbreaks in digital images, is nearing public availability. This tool will allow researchers and superintendents to more rapidly and accurately assess treatment effects.</li><br /> <li>Microbiome &amp; Resurgence Insights:&nbsp;Research has identified that the loss of bacterial-mediated pathogen suppression is a likely driver of dollar spot resurgence following intensive fungicide use.</li><br /> <li>UV-C Efficacy:&nbsp;Investigation into UV-C radiation treatment has demonstrated potential to significantly reduce dollar spot severity while providing physiological enhancements.</li><br /> </ul><br /> <p style="font-weight: 400;"><strong>Outputs</strong></p><br /> <p style="font-weight: 400;">Research Publications &amp; Manuscripts:</p><br /> <ul style="font-weight: 400;"><br /> <li>Host Resistance Data:&nbsp;Ongoing analysis of the host resistance project to prepare manuscripts for peer-reviewed publication.</li><br /> <li>Bentgrass Survey:&nbsp;Current outputs include survey data from superintendents regarding the adoption of resistant germplasm, highlighting evidence of why the market hasn&rsquo;t broadly accepted use. Preparation of publication for the bentgrass cultivar survey results, led by assistant professors Quincy Law and Tyler Carr.</li><br /> <li>Integrated Practices:&nbsp;Previous success with the publication "Efficacy of integrated cultural practices for dollar spot disease management on creeping bentgrass and bermudagrass" in the&nbsp;<em>International Turfgrass Research Journal</em>&nbsp;serves as a model for upcoming manuscripts.</li><br /> </ul><br /> <p><strong>Activities</strong></p><br /> <ul style="font-weight: 400;"><br /> <li>Annual Research Conference:&nbsp;The 2026 meeting was held at the University of Wisconsin, Madison, facilitating collaboration between 12 research institutions and industry partners.</li><br /> <li>Autonomous Mowing Research:&nbsp;A collaborative research project is underway involving six institutions to investigate the impact of autonomous mowing frequency and dew removal on disease severity. Autonomous mowers are at each site with data collection and treatments ongoing in the 2026 field season.</li><br /> <li>Germplasm &amp; Adoption Investigation: A central activity is investigating the research-to-industry gap. Superintendents at higher-end clubs often prioritize playability and turf quality over disease resistance and cost savings. Providing ROI motivation for superintendents is a key goal.</li><br /> <li>Fungicide &amp; Pathogen Research:</li><br /> <ul><br /> <li>Resistance Screening:&nbsp;Conducting high-throughput methods for quantifying fungicide resistance in field populations and researching molecular mechanisms of resistance in the dollar spot pathogen.&nbsp;</li><br /> <li>Clarireedia Biological Studies:&nbsp;Continued investigation into the characterization of&nbsp;<em>Clarireedia</em>&nbsp;species to understand the biological diversity of the pathogen in the context of fungicide resistance development and control.</li><br /> </ul><br /> <li>UV-C Treatment Trials:&nbsp;Research investigating the optimal doses of UV-C radiation required to reduce both dollar spot and Microdochium patch.&nbsp;</li><br /> </ul><br /> <p><strong>Milestones</strong></p><br /> <ul><br /> <li>Technological Integration &amp; Deployment:&nbsp; Establishing standardized protocols for autonomous mowing that can be target dollar spot reduction and be reliably integrated into turfgrass management practices that provide acceptable playing conditions.</li><br /> <li>Closing the Adoption Gap:&nbsp;Developing and disseminating evidence-based management frameworks specifically designed for resistant cultivars. We aim to move past the hurdle of "status quo" management by providing superintendents with the economic and performance data necessary to justify transitioning to improved germplasm.</li><br /> <li>Creation of Dollar Spot Resource: Plan and create a website to provide outreach of new and emerging research dedicated to dollar spot research, highlighting the efforts of this group.</li><br /> <li>Expansion of Scope: Expand research into dollar spot management in other turfgrass systems including lawns (Kentucky bluegrass) and warm season species (seashore paspalum).</li><br /> </ul><br /> <p style="font-weight: 400;"><strong>Future Plans</strong></p><br /> <p style="font-weight: 400;">In the coming year, the NC1208 group will focus on the practical application of autonomous technology and the drivers of cultivar adoption. We aim to provide superintendents with clear, data-driven guidelines on how to integrate technology into their standard operating procedures to maximize disease suppression.&nbsp;Additionally, we will continue to delve into the biology of the system, further understanding the mechanisms of fungicide resistance development and</p><br /> <p style="font-weight: 400;">Another overall goal of the group is to develop a plan for the future of funding this important research in development of a broad USDA SCRI proposal that would build upon the projects and cover the important knowledge gaps that still remain in the dollar spot pathosystem.</p><br /> <p>&nbsp;</p>

Publications

<p>Shahoveisi, F., Shah, K. K., Koch, P., Kaminski, J. E., Roberson, T., McCall, D., &amp; Nangle, E. (2025). Efficacy of integrated cultural practices for dollar spot disease management on creeping bentgrass and bermudagrass. International Turfgrass Society Research Journal, 15(1), 387-396.</p><br /> <p>Miller, G.L., Carpenter, M.C., Earlywine, D.T. 2025. Control of dollar spot on golf putting greens following post-application irrigation of fungicides targeting soilborne diseases. Crop Protection 196:107270.</p><br /> <p>Ruwona, J. and Miller, G.L. 2025. Determining the optimal ratio of resistant to susceptible bentgrass cultivars to reduce dollar spot severity. International Turfgrass Society Research Journal 1-10. doi:10.1,002/its2.149.</p>

Impact Statements

1. Dew removal can reduce dollar spot severity relative to a non-treated control by approximately 25% when done prior to 7:30 AM.
2. Biocontrol products failed to provide meaningful dollar spot suppression even on more resistant cultivars.
3. Smith-Kerns Dollar Spot Model thresholds can be significantly increased on disease-resistant cultivars. Further work will refine just how much they can be increased by.
4. Most superintendents don’t alter their disease management programs after seeding disease resistant cultivars. This is an opportunity for us as researchers and extension specialists to develop improved disease best management practices specifically for disease resistant cultivars.

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