Southern Corn Rust

Southern Corn Rust can occur in major regions for corn production in the US and Canada despite being a tropical disease. High humidity and temperatures around 80°F create a supportive environment for Southern Corn Rust to thrive.

Symptoms are similar to common rust, but pustules are smaller and occur almost exclusively on the upper leaf surface. Pustules are usually circular or oval, very numerous, and densely scattered over the leaf surface. Spores are orange when they erupt from the pustule. As pustules age, they become chocolate brown to black, often forming dark circles around the original pustule.

To protect corn crops, foliar fungicides labeled for Southern Corn Rust are available. Hybrids and inbreds showing resistance are also useful.

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