Extension Crop Report

Extension Crop Report

southern rust of corn
Southern rust of corn (Photo by Jenny Rees)

Aug. 1, 2014

Jenny Rees, Extension Educator in Clay County: Southern rust of corn was confirmed in Clay County July 31. It appears as very small, tan-brown lesions on the upper surface of the leaf, usually in clusters. Spores inside the pustules are typically orange. This was found on one leaf in a field near Trumbull. Just because southern rust has been found in the area, we don't recommend automatically spraying. Scout your fields and consider disease pressure, growth stage, and economics. Long season corn and late-planted fields have the potential for the most damage. Secondary common rust sporulation has also been confused as southern rust as the secondary pustules tend to look like this. It's important to obtain microscopic confirmation to know for sure if you have southern rust in your fields. (See related article, Southern Rust Update.)

This week we also saw drought stress in some dryland soybean fields. Closer observation shows plants aborting pods and losing their lowest leaves. For more of this crop report, see Rees' extension blog, JenREESources.