Cause A fungus, Tilletia controversa, which survives as spores in soil or in smut balls in seed. A wide range of species in 14 genera of Gramineae are susceptible to this disease including species of Aegilops (goatgrass), Agropyron (wheatgrass), Arrhenatherum (oatgrass), Bromus (bromes, cheat grasses), Dactylis (orchardgrass), Elymus (squirreltail), Festuca (fescues), Koeleria (junegrasses), Lolium (ryegrass), and Poa (bluegrasses, etc.) as well as varieties of barley, rye, and wheat.
Symptoms Infected plants are stunted. There may be flecks on the leaves, increased tillering, and seed heads are one quarter to one half the size of healthy heads. Kernels are replaced by smut balls containing masses of dark spores with a foul odor.
Cultural control Plant grass only in spring and promote emergence and vigorous growth the first summer.
Reference Hardison, J.A. et al. 1959. Mycologia 51:656-664.