Planting infected seed early when soil temperatures are above 60 degrees F generally increases loss from seedling blight. Head scab of wheat Stagonospora glume blotch, caused by the fungus Stagonospora nodorum has increased in the US in recent years probably due to expanded use of nitrogen fertilizers, semidwarf wheat varieties, and reduced tillage. Symptoms can develop throughout the growing season on all above-ground plant parts. Initial symptoms are small chlorotic flecks usually on lower leaves or those in contact with soil. The glumes of the wheat heads become infected in late spring before flowering.
Lesions generally begin at the glume tips and are dark brown in color.
During favorable weather, the fungus penetrates the glumes and infects the seed causing severe shriveling of the grain. With the onset of moist weather, spores are produced and are spread to healthy wheat plants by splashing rain.