Susceptibility of Maize to Gibberella zeae Ear Rot: Relationship to Host Genotype, Pathogen Virulence, and Zearalenone Contamination. D. Cullen, Research Associates, Department of Plant Pathology, University of Wisconsin, Madison 53706. R. W. Caldwell, Research Associates, and E. B. Smalley, Professor, Department of Plant Pathology, University of Wisconsin, Madison 53706. Plant Dis. 67:89-91. Accepted for publication 17 June 1982. Copyright 1983 American Phytopathological Society. DOI: 10.1094/PD-67-89.

Susceptibility to Gibberella zeae ear rot differed significantly between certain inoculated corn (Zea mays) inbreds (A619, A632, A634, and Mo17) and single-cross hybrids (A619 × A632 and Mo17 × A634). Significant differences (P= 0.05) in the pathogenicity of two G. zeae isolates were also observed. Zearalenone concentrations in infected ears varied according to corn line and fungus isolate. The less virulent isolate produced relatively more zearalenone in culture and in diseased ears. Estimates of disease severity (percent ear rot) were good predictors of zearalenone contamination and may be useful in selecting desirable corn lines.