Late-Season Colonization and Survival of Fusarium graminearum Group II in Cornstalks in Minnesota. Carol E. Windels, Assistant Professor, Northwest Experiment Station, University of Minnesota, Crookston 56716. Thor Kommedahl, Professor, Department of Plant Pathology, University of Minnesota, St. Paul 55108. Plant Dis. 68:791-793. Accepted for publication 14 March 1984. Copyright 1984 The American Phytopathological Society. DOI: 10.1094/PD-68-791.

From 1973 through 1983, 14.6% of nearly 7,500 green cornstalks, collected from mid-September through early November, were infected by Fusarium graminearum. Of rotted (standing or lodged) stalks collected at the same time as green stalks in 1981 and 1982, 84.4% yielded F. graminearum. Recovery of F. graminearum from overwintered, standing cornfields the following spring was 61%, and recovery from 1-yr-old basal stalk pieces the following fall was 31%. Mature perithecia of Gibberella zeae developed in 99% of the isolates tested, which verifies the occurrence of the Group II population on corn in Minnesota. F. graminearum gains possession of pith tissue late in the growing season as stalks ripen and it predominates as tissues senesce, thereby increasing its inoculum potential and survival niches for the following season.

Keyword(s): stalk rot.