Turfgrass disease prevention Q&A: brown ring patch
By Mike Agnew, Ph.D., technical services manager for Syngenta
Brown ring patch primarily affects annual bluegrass and becomes more active in the early spring and summer as daytime temperatures increase. As it starts to warm up, be in the know about brown ring patch, how to accurately diagnose it and preventive measures to take that will keep your turf stay healthy all season long.
What is brown ring patch?
Brown ring patch also referred to as Waitea Patch, is caused by the pathogen Waitea circinata var circinata. The name can be somewhat misleading as symptoms closely resemble those of yellow patch. Brown Ring Patch symptoms mostly appear as solitary or clusters of yellow rings that range from several inches to a foot in diameter. Over time, the rings become necrotic with sunken margins, which create a bumpy playing surface.
To quickly diagnose brown ring patch versus yellow patch, check for mycelium by placing a sample of infected turf in a container or plastic bag overnight. If the sample has mycelium on the foliage, soil or thatch in the morning, brown ring patch is present.
When does brown ring patch occur?
Disease symptoms usually appear in spring or early summer when air temperatures are between 60°F-75°F, skies are overcast and rain. Sign up for Soil Temperature Alerts to receive personalized alerts on potential pest activity and access 10 years of soil temperature archives.
Which turf species are affected by brown ring patch?
Brown ring patch primarily affects Poa annua golf course greens.
What are some good management tips?
While affected turf normally recovers with the advent of sunny and dry weather, the application of a small amount of water-soluble nitrogen (0.125 to 0.25 lbs. N/1,000 ft.²) will promote recovery. When rings are numerous and objectionable, an application of an appropriate fungicide may be warranted.
What type of control methods are available?
If there is a history of brown ring patch, it is best to combat the disease with a preventive fungicide application on greens and tees. Depending on the climate and spring warm-up, preventive fungicide applications should generally occur between March 15 and June 1. Fungicides include, Ascernity®, Banner Maxx® II, Briskway®, Heritage® Action™, Heritage® TL, Medallion® SC, Posterity® XT and Renown® fungicides.
Curative applications should be made at the first sight of brown ring patch. Applying Heritage TL or Heritage Action at label rates is an excellent choice.
Preventive application of Heritage® TL fungicide
Untreated and preventive applications from Brown Ring Patch Trials at Fiddler’s Elbow Country Club in Bedminster Township, New Jersey in 2011.
©2021 Syngenta. Important: Always read and follow label instructions. Some products may not be registered for sale or use in all states or counties. Please check with your state or local extension service to ensure registration and proper use. Action™, Ascernity®, Banner Maxx®, Briskway®, Heritage®, Medallion®, Posterity®, Renown® and the Syngenta logo are trademarks of a Syngenta Group Company.
For more information about brown ring patch, contact your local Syngenta territory manager.