A couple of weeks ago, Scott Blough from Nassau Country Club asked me about the impact of applying DMIs on turf that was showing symptoms of etiolation. While I had heard varying thoughts on this from the industry, my only real suggestion was, “Go ahead and try and let me know what happens.” Well here’s Scott’s response to what he observed with his etiolation issues that started to show up earlier this month.
“As soon as the weather changed from being dry to more humid, etiolation began to develop in certain areas of my Alpha, A1 and A4 greens. It started in the collars and moved to the greens only in areas with little to no morning sun. All greens were sprayed up for Pythium Root Dysfunction and Rot. There was labeled rate of Primo applied just prior to the start of the etiolation. Once the weather turned cooler, 2 oz/m of Banner Maxx was applied and left on the surface. All etiolation disappeared shortly after the application and has not developed again. Strictly Trimmit was applied after this and Primo was completely taken out of the program. Ammonium Sulfate was also not used any more.
The decline has subsided and are now in recovery. The key to the recovery is stopping the algae from setting in by using Daconil and Fore in rotation. Eliminating the Ammonium Sulfate, even if watering in, and also Primo. Spraying Trimmit has also helped. It is good to spend the time to scratch the decaying leaf blades and raise them up to allow air and also new plants to emerge in the declining areas. I feel it is important to not apply P, because it seems to encourage the algae growth. Also, remove trees that prevent morning sunlight on Bentgrass greens.”
Scott Blough, Superintendent Nassau Country Club
While these are only observations, Scott’s take home message for his issue was to remove ammonium sulfate and Primo from his program and that the DMI application appeared to knock back or prevent additional etiolation symptoms. While these are anecdotal observations, at this point I think superintendents are willing to try anything as there doesn’t seem to be a lot of research based management options out there.