Fusarium Blight and Physical, Chemical, and Microbial Properties of Kentucky Bluegrass Sod. R. W. Smiley, Assistant Professor, Department of Plant Pathology, Cornell University, Ithaca, NY 14853. M. M. Craven, and J. A. Bruhn, Research Support Aide, and Graduate Research Assistant, respectively, Department of Plant Pathology, Cornell University, Ithaca, NY 14853. Plant Dis. 64:60-62. Accepted for publication 21 March 1979. Copyright 1980 American Phytopathological Society. DOI: 10.1094/PD-64-60.

Kentucky bluegrass (Poa pratensis) may become severely damaged by Fusarium blight. When the disease occurred on a well-established plot, its dependence on the environment, a relationship that is not well understood, was studied. Factor analysis was performed to identify associations between Fusarium blight and the other variables. The disease was positively correlated with the thatch decomposition rate, negatively correlated with the plant growth variables, and not correlated with any microbial group including all species, sections, and composite numbers of Fusarium. Sod pH and Fusarium numbers were associated with thatch decomposition rates. Fusarium blight was least severe when the percentage of Fusarium-infected plant crowns was highest. These results are considered in relation to the possible role of phytotoxic substances that are produced during thatch decomposition and act as incitants of Fusarium blight of Kentucky bluegrass.