Distribution of Mycelial Colonies and Lesions in Field-Grown Barley Inoculated with Fusarium graminearum.

ABSTRACT External surfaces of barley florets have thick-walled epidermal cells resistant to direct penetration by the head blight pathogen, Fusarium graminearum. Surfaces within the floral cavity have thin-walled, susceptible cells. How the fungus gains access to the floral cavity, causing head blight, has not been determined.