Diseased grain heads. Photo by Steven B. Johnson. Fusarium Head Blight (Head Scab of Barley) (PDF) By Steven B. Johnson, Extension Crops Specialist, University of Maine Cooperative Extension For information about UMaine Extension programs and resources, visit extension.umaine.edu.Find more of our publications and books at extension.umaine.edu/publications/. Fusarium head blight, or head scab of barley, is