Rhizoctonia cerealis Causes Yellow Patch of Turfgrasses. Lee Burpee, Plant Pathologist, Bermuda Department of Agriculture and Fisheries, Hamilton 5, Bermuda. Plant Dis. 64:1114-1116. Copyright 1980 American Phytopathological Society. DOI: 10.1094/PD-64-1114.

Isolates of a binucleate Rhizoctonia sp. that cause chlorosis and blight of turfgrasses fit the species concept of Rhizoctonia cerealis. Mycelial and sclerotial characteristics, temperature-growth relations, and hyphal anastomosis of 10 of these binucleate Rhizoctonia isolates, which had previously been assigned to anastomosis group CAG 1, were compared with the characteristics of three isolates of R. cerealis from small grains. The 10 unidentified isolates and the isolates of R. cerealis exhibited similar cultural morphology and were assigned to the common anastomosis group CAG 1. Radial growth rates on potato-dextrose agar were 3.3–5.0 mm/day at 23 C. Based on these criteria, isolates of R. cerealis are assumed to be the cause of chlorosis and blight of turfgrasses, and the descriptive name “yellow patch” is proposed for the disease caused by R. cerealis on turfgrass species.