It is prevalent in moist, warm seasons from heading time onward. Seedling blight also is a destructive phase of the disease that causes financial losses to grain growers in the state. The severity of scab infection varies greatly from year to year and is closely associated with the prevailing weather conditions after the heads emerge. Yet in years that are dry after heading begins, only a trace of scab can be found. Fortunately, latter conditions are more prevalent in Missouri.
Grain infected with scab is usually light and chaffy.
This condition reduces its feeding value and consequently its market value. Grain containing 10 percent or more scabby kernels fed to hogs may cause vomiting. The scab fungus attacks wheat, barley, oats, rye, corn and a number of other grasses including cheat, wild rye, foxtail, quackgrass, crabgrass and bluegrass. It may also attack clover, alfalfa, pokeweed, and some plants in the parsley family. However, it is most prevalent on wheat, barley, rye and corn.