Yesterday common corn rust was found in Mitchell county in isolated areas. Rome Ethredge in Seminole County is seeing some in his county as well.
First off this is NOT Southern Rust, so don’t worry. This disease is very similar but NOT the kind of rust that causes significant yield loss. This disease is almost always found each year and rarely causes any yield loss and is of no worry to our corn producers.
Common corn rust (Puccinia sorghi) can be easily recognized by the development of dark, reddish-brown pustules scattered over both the upper and lower surface of the corn leaves. Pustules appear oval to elongate in shape, are generally small, less than 1/4 inch long, and are surrounded by the leaf epidermal layer, which appears as a whitish covering. These pustules may appear on any above ground portion of the plant, but are most abundant on the leaves.
By the way I have been looking at multiple fields for southern rust, northern corn leaf blight and southern corn leaf blight. I have NOT seen a field yet that needs a fungicide application. Some producers are going for higher yields and have applied fungicides at tassel. This may bump yields, but according to UGA research, not enough to be economical with little to no disease pressure. Either way I can understand someone’s concern considering last year’s losses to southern rust!
Here are the rust pustules up close. Note the spore are a darker color.