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Issue link: http://gcmdigital.gcsaa.org/i/632307
02.16 GOLF COURSE MANAGEMENT 101 First report of brown ring patch caused by Waitea circinata on perennial ryegrass in Oklahoma Nathalia Graf Grachet, M.S., and Nathan Walker, Ph.D. Brown ring patch of cool-season turfgrass, caused by Waitea circinata, was frst reported in Japan on creeping bentgrass (Agrostis palustris Huds.) in 2005, and in the United States on annual bluegrass (Poa annua L.) in 2007. In April 2015, a rapid decline was observed on a stand of perennial ryegrass (Lolium perenne cultivars Soprano, 1G 2 , and APR2116) that had been overseeded on a bermudagrass stand at a baseball feld in Still - water, Okla. Symptomatic leaf tissue was surface-sterilized and plated onto potato dextrose agar (PDA). A R izoctonia-like fungus was consistently isolated and suspected to be the causal patho - gen. After three days at 77 F (25 C), white, cottony growth formed in the culture, which turned orange to brown as the culture aged. Spherical sclerotia of irregular diameters were present in the 7-day-old culture that followed the same color development as mycelia. Colony and sclerotia morphology were consistent with previous descriptions of W. circinata. DNA products were sequenced and showed 100% simi - larity to published ITS sequences (GenBank Accession Nos. HM807352, HQ166071, FJ55889). A pathogenicity test was Disease updates Editor's note: Each year, reports of previously unknown diseases, sightings of diseases in areas where they had not been seen before, and other news of diseases related to turfgrass are published in the scientifc literature. From time to time, GCM will print this information in its research section. In this issue, we've published reports that appeared in the journal Plant Disease during the past year. (report) Brown ring patch caused by Waitea circinata was found on three perennial ryegrass cultivars that had been overseeded on a bermudagrass stand at a baseball feld in Stillwater, Okla. Photos by Todd Tribble