Pathogenicity of Rhizoctonia zeae on Tall Fescue and Other Turfgrasses. S. B. Martin, Jr., Former Graduate Research Assistant, Department of Plant Pathology, North Carolina State University, Raleigh 27650. L. T. Lucas, Professor, Department of Plant Pathology, North Carolina State University, Raleigh 27650. Plant Dis. 67:676-678. Accepted for publication 30 November 1982. Copyright 1983 American Phytopathological Society. DOI: 10.1094/PD-67-676.

Isolates of Rhizoctonia zeae were collected from various turfgrass sources and compared with one isolate of R. solani (anastomosis group 1) from tall fescue (Festuca arundinacea) and one isolate of R. zeae from corn roots (Zea mays) morphologically and for ability to induce foliar blight on turfgrasses in greenhouse studies. Tall fescue, perennial ryegrass (Lolium perenne), Kentucky bluegrass (Poa pratensis), creeping bentgrass (Agrostis palustris), common bermudagrass (Cynodon dactylon), and centipedegrass (Eremochloa ophiuroides) were inoculated with each of five isolates of R. zeae and one isolate of R. solani, R. zeae isolates blighted cool-season turfgrasses more severely than warm-season turfgrasses. Isolates of R. zeae originally obtained from lesions on grasses were more virulent on cool-season grasses than an isolate from corn roots and one from bentgrass affected with a summer dry wilt condition. Isolates of R. zeae were only mildly pathogenic on warm-season grasses. The R. solani isolate was more virulent than any of the R. zeae isolates tested.

Keyword(s): brown patch, Rhizoctonia cerealis.