Scab is initiated by infection of floral parts, glumes, and spikelets during warm, wet weather. Plants are most susceptible at anthesis. Infection leads to development of shriveled and moldy grain. Spikelets distal to infection may be barren or contain very shriveled grain, but not contain the pathogen. Infected grain contains mycotoxins harmful to livestock and humans.
Control is primarily through crop rotation.
Rotations should have a non-host between corn and wheat. Tillage that buries corn debris may also have some effect, since the pathogens survive better above ground. Good sources of resistance are still lacking and chemical control of head blight is not attempted. Seed treatments only control the seedling blight phase. A visual rating scale has been developed for assessing scab.