Southern rust of corn, caused by the fungus Puccinia polysora, has now been confirmed in Illinois for the 2026 growing season. The first report was received on July 23 from Williamson County in southern Illinois.
This confirmation indicates that southern rust spores have reached the state and that corn growers and agronomists should begin scouting, particularly in fields with susceptible hybrids that have not yet reached the later reproductive stages. The disease can develop rapidly under warm, … Continue reading First Southern Rust Report of 2026 in Illinois: What Corn Growers Should Know