wheat scab, head blight, humid weather condition
Scab, also known as head blight, head scab or pink mold, is a fungal disease which can attack spring and winter wheat as well as other small grains. It is generally most serious under wet or humid weather conditions, such as that experienced in South Dakota and the upper Great Plains in 1993. Scab was observed in some winter wheat fields and was particularly severe in spring wheat and some barley fields.
Gallenberg, Dale J., "Wheat Scab" (2002). SDSU Extension Extra Archives. 297.