Brief Summary of Minutes of Annual Meeting

Short-term outcomes: The ‘Combined Cultural Practices’ project was conducted in 2021 across 8 locations (Connecticut, Massachusetts, Penn State, Kansas State, Virginia Tech, Ohio State, Clemson, and Wisconsin). The results from just the Wisconsin location can be viewed here (https://tdl.wisc.edu/wp-content/blogs.dir/42/files/Interactive%20Pages/2021_Summer/Reports/UWDSCultural_2021.pdf). Overall there were few treatment impacts using AUDPC. However, a quick look over individual rating dates found that many sites had individual dates with treatment differences. In general none of the treatments provided commercially acceptable dollar spot control. The sites with the most treatment differences were the two run by Virginia Tech. Both these sites found significant reductions of dollar spot with the dew removal treatments, of importance Va Tech was the only group that removed their dew early in the morning (ie earlier than 7 AM). Most other sites removed dew at 7 AM or later (we did it at approximately 7:30 in WI), and the suppressive effects were much less apparent at the later dew removal times. Timing of dew removal appears to be a key factor in its efficacy as a cultural practice.

Outputs: In addition to the ‘Combined Cultural Practices’ project detailed above, the NC1208 team also planted a project called ‘Resistant Cultivar’ project at 7 locations (Kansas State, Michigan State, Penn State, Rutgers, Massachusetts, Wisconsin, and a USGA facility in North Carolina). The planting consisted of 3 cultivars of varying resistance to dollar spot. Penncross was planted as the most susceptible cultivar, Shark as the moderately resistant cultivar, and Coho as the most resistant cultivar. In 2022 each location will implement dew removal and the use of biocontrols to determine the efficacy of each cultural practice on bentgrasses with varying susceptibility to dollar spot.

Activities:

• Dollar spot fall sequencing: Thiry-six isolates collected from Wisconsin and New Jersey during the summer and fall of 2020 have now been completely sequenced and are ready to analyze. A call will be set up to discuss the sequence results and what future steps may be taken (if any) to follow up on these initial sequences.
• Bentgrass survey: A survey was created in spring 2022 to identify factors superintendents use when selecting bentgrass cultivars so that we can encourage increased adoption of disease-resistant cultivars. The survey was distributed out via email and social media on March 7^th, 2022 and will remain open until approximately April 1^st. The results will be analyzed by the USGA.
• Remote sensing of dollar spot: Dave McCall’s Virginia Tech team provided an update on their remote sensing/imaging project. Their drone imaging appears to do an excellent job of mapping dollar spot outbreaks, and they are looking for other partners to work with and test the concept. Paul Koch mentioned that there might be some compatibility with research at UW looking to use the dollar spot prediction model to implement a precision disease management spraying system based on dollar spot probability data.
• Potential future project #1: Lee Miller (Purdue) proposed a project to study the transition to a more resistant cultivar through repeated interseeding and without killing the turf present. This would seemingly increase the number of courses that could afford to transition because it wouldn’t require the closure of the course. Assessing the success of the transition could be done both by reduction in dollar spot severity over time and by using molecular markers to quantify the presence of particular cultivars. It’s unclear if this project will be able to implemented in 2022. Joe Vargas brought up the concern of annual bluegrass dominating the stand and not allowing for a transition.
• Potential future project #2: Paul Koch proposed a project to the groups participating in the ‘Resistant Cultivar’ project. The project would entail testing different dollar spot model spray thresholds on each of the three cultivars. The team could then compare the thresholds identified for each cultivar and use the model to estimate how much fungicide savings any golf course in the world could achieve by transitioning to a more resistant cultivar simply by entering their past environmental data into the model. The project would involve 5-6 treatments on each of the cultivars and daily monitoring of the dollar spot model. At this point the study is more likely to be implemented in 2023 instead of 2022.
• Dissemination of product findings: The group briefly discussed ways to disseminate findings. Dissemination will include articles in regional and national trade journals, one or more field days towards the end of the project, and perhaps a national seminar at the GCSAA Conference or other venue.

NC1208 has a number of collaborative projects in place for 2022 and potentially more planned for 2023. Additional data analysis will occur in the fall and winter of 2022-2023 and publications will begin to be prepared in 2023.

We intend to meet as a group, virtually or in-person, in early 2023 to discuss the results from 2022 and plan ahead for 2023.

None to date