Smut Expression and Resistance of Corn to Sphacelotheca reiliana in Minnesota. E. L. Stromberg, Department of Plant Pathology, University of Minnesota, St. Paul 55108. W. C. Stienstra, T. Kommedahl, C. A. Matyac, and C. E. Windels, Department of Plant Pathology, and J. L. Geadelmann, Department of Agronomy and Plant Genetics, University of Minnesota, St. Paul 55108.. Plant Dis. 68:880-884. Accepted for publication 17 April 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-880.

Head smut caused by Sphacelotheca reiliana occurred in 1980–1983 in only four counties in north central Minnesota. In resistance trials in 1981 and 1982, 56% of 238 inbreds and hybrids had at least 5% smutted plants. Of 168 elite hybrids, 113 were resistant or moderately resistant to S. reiliana. Planting date within a given year did not significantly affect smut incidence; however, more plants were smutted in 1982 than in 1981. Twice as many ears as tassels were smutted and about half of the smutted plants were stunted. Leaf infection and phyllody occurred sporadically. Single crosses were intermediate in smut incidence between their resistant and susceptible inbred parents. Applying teliospore-infested soil to kernels at planting was an effective method to evaluate resistance of inbreds and hybrids in the field.

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