In the past several weeks we've encountered some irregular patches of stressed turf on our putting surfaces. We first discovered this problem on number 3 green shortly after the winter green's covers were removed. Since that time we've seen the problem spread to several other greens, most noticeably number 14. As many of you know we then made the decision to close number 14 green until the turf had the proper time to recover. During this time we closely monitored the affected putting surfaces and several samples were sent out to turfgrass diagnostic labs. Basically, we did everything in our power to properly diagnose the affected turfgrass plants. We already knew that whatever was causing the turf to decline was only happening to a certain species of turfgrass, poa annua. Therefore, we focused on issues that normally affect poa annua including- winter kill, wind dessication, drought stress, pink snow mold, and many other fungal pathogens. We knew that there was a very small chance that our greens had been affected by a fungal pathogen because we haven't had the necessary weather conditions. Then after many hours of research and phone calls to turfgrass scientist, we discovered that the problem was actually a disease called bacterial wilt. Bacterial wilt is the only known bacterial disease of turfgrasses in the United States. The disease was originally discovered on Toronto creeping bentgrass by Dr. Joe Vargas at Michigan State University in the early 70's. Dr. Vargas then discovered the same disease on poa annua putting greens in the late 80's. Since that time no known chemical or culture practice has been found to be effective in controlling bacterial wilt. To explain that point further we included a paragraph from msuturfdiseases.net:
"Culturally, there is little that can be done to manage this disease.
Mowing can be implemented in the afternoon, once the turf has dried to
discourage the spread of the bacterium on wet turfgrass. Mowers should
be dedicated for use only on affected greens and should be disinfested
with bleach after use. Mowing height should be increased and mowing
frequency decreased. Abrasive cultural practices, such as vertical
cutting, topdressing and aeration, should be avoided when the disease is
active. Greens chronically affected by bacterial wilt should be
reestablished with resistant cultivars.
All of the seeded cultivars of creeping bentgrass have so far been
resistant to bacterial wilt caused by X. translucens".
We also included a paragraph on possible chemical controls from an expert plant pathologist, Dr. Nathaniel Mitkowski:
"If bacterial wilt is already present, there is no easy solution. When we deal with fungal diseases, there is no end to the "quick-fixes". Fungicides are in abundant supply and they are extremely effective. There are no "quick-fixes" for bacterial wilt. The chemicals we do have only slow disease spread but do not eliminate it".
With that said, bacterial wilt is obviously a very serious problem that cannot be remedied overnight. We've been fortunate in that the weather has cooperated in the last few weeks so that nearly all affected areas had a chance to recover. Number 14 is still not fully recovered but it's come a long way in the past week or so. Regardless, as we continue to push for faster green speeds there's no question that the disease will eventually resurface. As the only way to completely solve this problem is to re-grass our greens with resistant bent grass cultivars. This has already been done on number 8 green and as you can see the green has remained in nearly perfect condition throughout the Spring.
For more information please read the attached article- www.turf.uconn.edu/pdf/research/factsheets/Disease_Bacterial_Wilt.pdf
Thank you for your time and please feel free to contact us at anytime.
