Internal smuts

Internal smuts: biology

Spores are spread from smutted heads by wind or rain splash to healthy heads and invade the developing grain. Infected seed appears normal and will germinate. The following year after germination the fungus grows with the plant and replaces the head with spores.

Diseased plants appear normal until heading when infected heads are black and filled with dusty spores. The spores are quickly dispersed and soon only a bare central axis (rachis) remains. False loose smut of barley is similar in appearance to true loose smut but false loose smut behaves like covered smut. These two diseases can be distinguished only in a laboratory test. When in doubt consider the disease to be loose smut.

Loss in yield is directly related to the percentage of diseases tillers. There is no effect on grain quality.