Extension of Range of Grovesinia pyrarnidalis on Black Walnut. K. J. Kessler, Jr., Forestry Sciences Laboratory, USDA Forest Service, Southern Illinois University, Carbondale 62901. E. M. Hayes, Minnesota Department of Natural Resources, Division of Forestry, Rochester 55904. Plant Dis. 68: 918. Accepted for publication 25 June 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-918e.
Zonate leaf spot of black walnut (Juglans nigra L.), caused by Grovesinia pyramidalis (M. Cline, Crane, S. Cline [anamorph Cristulariella moricola Hino] Redhead), was found for the first time in Iowa and Minnesota in 1982 and 1983, respectively. The disease caused moderate defoliation in walnut plantations in the Yellow River State Forest in northeastern Iowa and severe defoliation in a 13-yr-old pole- size walnut plantation in Wabasha County, southeastern Minnesota. This disease has previously been reported only in Illinois, West Virginia, and Ohio. These new findings extend the western and northern reported range of zonate leaf spot on black walnut.