Glume blotch is caused by fungi surviving on crop residues and on volunteer wheat. Glume blotch development is favored by splashing rain, high humidity, and mild temperatures. Infections tend to result in yield losses and shriveled kernals.
This disease causes dark brown or purple lesions on heads. Lesions are often more intense at the top of the glume, with brown streaks or blotches extending down toward the base of the spikelet. The disease may spread to the head from leaf infections initiated earlier in the growing season.