Speckled leaf blotch can infect wheat in the fall but is most damaging when the disease attacks the upper leaves and heads of susceptible varieties late in the season. Infections do not always result in damage, but can under favorable conditions.
This fungal disease causes tan, elongated lesions on wheat leaves. Lesions may have a yellow margin, but the degree of yellowing varies among varieties. Rows of dark, reproductive structures produced by the fungus are key diagnostic features and can often be seen without magnification.