Southern Rust Impacts Nation's Corn Crop
Southern rust is having a significant impact on corn crops in the Midwest and northern United States in 2025, according to Corteva.
Weather Conditions Contribute to Outbreak
The weather conditions in 2025 were ideal for a southern rust outbreak, resulting in late-season disease management decisions for many growers.
Characteristics of Southern Rust
Southern rust is a fungal foliar disease that thrives in hot and humid conditions, requiring a living host to reproduce. The spores are typically spread by wind and rain from the south.
- 86% of attendees at a recent Pioneer webinar experienced southern rust in 2025.
- Almost 50% dealt with southern rust at least once between 2020 and 2024.
“June was warm, but July was warmer and one of the wettest on record in the north-central Corn Belt. Those are the conditions you need for southern rust to thrive,”
said Carl Joern, Pioneer field agronomist in Indiana.
Author summary: Southern rust affects US corn crop.