Symptoms of common rust often appear after silking.

Small, round to elongate brown pustules form on both leaf surfaces and other above ground parts of the plant.

As the pustules mature they become brown to black.

If disease is severe, the leaves may yellow and die early.

Disease development is favored by cool, moist weather 15-21 D.C

Image Source- https://extensionpubs.unl.edu/publication/g1680/na/html/view