Characterization of the Chlorotic Lesion Response by Maize to Cercospora zeae-maydis . J. T. FREPPON, Graduate Student, Department of Agronomy, Ohio Agriculture Research and Development Center, Ohio State University, Wooster 44691. P. E. LIPPS, Professor, Department of Plant Pathology, and R. C. PRATT, Assistant Professor, Department of Agronomy, Ohio Agriculture Research and Development Center, Ohio State University, Wooster 44691. Plant Dis. 78:945-949. Accepted for publication 15. June 1994. Copyright 1994 The American Phytopathological Society. DOI: 10.1094/PD-78-0945.

Previous research indicated that variation in symptom response to Cercospora zeae-maydis is associated with maize genotype. An association between lesion type at a specific time and overall symptom response has not been described. Inbreds and hybrids grown at several locations during 1989 1992 were artificially inoculated with C. zeae-maydis. Genotypes were evaluated for lesion type responses and percent area affected on ear leaves. These evaluations and determinations of secondary sporulation were performed in 1991 and 1992. Lesion size reduction, delay in disease progress, and inhibition of sporulation were associated with chlorotic lesions on resistant inbreds NC250A, NC288, and NC262A. Pa875 had fleck lesions that developed into necrotic, susceptible lesions by the end of the season, although lesions were few in number and restricted in size. Hybrids developed by crossing chlorotic lesion inbreds with nonchlorotic lesion inbred B73 displayed the chlorotic lesion response, indicating the response may be controlled by dominant allelic interaction.