Biology Common root rot is consistently one of the most damaging diseases of wheat and barley. It can also infect oats, rye and triticale. The seedling blight phase is less common on wheat than on barley. In the mature plant, root rot caused primarily by Cochliobolus sativus is the major cause of crop loss. The leaf spot and head infection phase is less important on the prairies than in the eastern provinces.
Initial infections originate from soil-borne spores.
Seedlings become infected following germination and further infections continue throughout the growing season. Abundant spore production occurs on diseased tissue. Spores are spread by wind, water, cultivation and through infected seeds. Spores may remain viable in soil for several years until stimulated to grow by the presence of a host plant. Cold soils, as well as drought and high temperature stress are important predisposing factors for an infection.