Brown Ring Patch on the putting green and a few other greens

Brown ring patch is a recently described Rhizoctonia-like fungus disease of turf grass; it is caused by the fungus Waitea circinata var.circinata. The disease is characterized on putting greens by the outer edge of the patch turning brown, but in many cases the predominate symptom pattern is the appearance of yellow rings that can be several inches to over a foot in diameter. This pathogen was first found damaging creeping bentgrass in 1994 in Japan. When researchers did genetic work to identify the cause, the pathogen was found to be the same on creeping bent grass as it was on Poa annua. The first observance in the United States was reported in California in 2003, then Oregon and Washington in 2004 and 2005. In 2006 and 2007, the disease reached the Mid-Atlantic and Upper Mid-West. The disease, which often infects high maintenance turf, can be difficult to control because root infection often occurs six to eight weeks before the appearance of foliar symptoms