Cocklebur: A New Host for Several Sclerotinia Species. P. B. Adams, Plant Pathologist, Soilborne Diseases Laboratory, Plant Protection Institute, USDA, ARS, Beltsville, MD 20705. B. H. Marose, Extension Assistant, Department of Entomology, and E. M. Dutky, Extension Assistant, Plant Diagnostic Clinic, Department of Botany, University of Maryland, College Park 20742. Plant Dis. 67:484-485. Accepted for publication 19 October 1982. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1983. DOI: 10.1094/PD-67-484.

Sclerotia were observed for the first time within the stems of cocklebur (Xanthium pensylvanicum) growing in a Maryland soybean (Glycine max) field. No previous record of cocklebur as a host of any Sclerotinia sp. has been found. Experiments showed that S. sclerotiorum, S. minor, and the field isolate from cocklebur were equally virulent on cocklebur, whereas S. trifoliorum was less virulent.