The key diagnostic feature of tan spot is tan lesions with a yellow margin. Mature tan spot lesions often have a dark area in the center. Lesions may merge as they expand, resulting in large sections of diseased leaf tissue. The fungus that causes tan spot survives in the debris of previous wheat crops and produces small, black reproductive structures in the spring.

Management: Avoid planting into wheat residue, tillage where appropriate, genetic resistance, foliar fungicides.