VIEW ARTICLE

Competitive Saprophytic Ability of Fusarium roseum f. sp. cerealis ‘Culmorum’ in Soil. Robert F. Nyvall, Department of Plant Pathology, University of Minnesota, St. Paul 55101, Present address: Iowa State University, Ames 50010; Thor Kommedahl, Department of Plant Pathology, University of Minnesota, St. Paul 55101. Phytopathology 63:590-597. Accepted for Publication 17 November 1972. DOI: 10.1094/Phyto-63-590.

Fusarium roseum f. sp. cerealis ‘Culmorum’ was not a good saprophytic colonist of wheat stems in a soil-peat-sand mixture. The soil fungi Aspergillus niger, Chaetomium globosum, and Trichoderma viride rapidly colonized untreated wheat stems placed in soil thereby preventing colonization by Culmorum. Nonsoil fungi Alternaria tenuis and Helminthosporium sativum were less successful in preventing colonization of wheat stems by Culmorum. Inability of Culmorum to colonize untreated wheat stems may partially explain the lack of increase in the population of this fungus in plots where susceptible wheat varieties have been grown for 7 years.