Lesions become dark in the center as conidiophore development occurs. Extensive development of pseudothecia may occur on straw and provides abundant primary inoculum. Development and dispersal of inoculum, as well as infection are favored by prolonged periods of wetness. Seedborne inoculum is no t a factor. Yield loss is associated with the degree of damage to the flag leaf.
Control is primarily through tillage and stubble management and the use of fungicides.
Some resistance to tan spot exists among some cultivars. Snow molds are a problem of winter cereals. Snow provides insulation for plants from freezing and desiccation, but also provides ideal conditions for growth of these fungi. Snow molds are not host specialized and cause general rot and necrosis of invaded tissue. Infected plants may recover in crown remain undamaged by the pathogens.