VIEW ARTICLE

The Development of Hypoxylon Canker of Populus tremuloides: Role of Ascospores, Conidia, and Toxins. Davinderjit K. Bagga, Former Research Assistant, Department of Plant Pathology, University of Wisconsin, Madison 53706; Eugene B. Smalley, Professor, Department of Plant Pathology, University of Wisconsin, Madison 53706. Phytopathology 64:654-658. Accepted for publication 26 November 1973. DOI: 10.1094/Phyto-64-654.

Water-soluble, heat-resistant materials produced in culture by Hypoxylon pruinatum caused extensive bark necrosis when applied to unwounded quaking aspen (Populus tremuloides) stems. Wound inoculations with ascospores resulted in running cankers only when combined with topical applications of these phytotoxic culture filtrates.