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 Agropyron, Bromus, Dactylis, Elymus, Festuca, Lolium, and Poa grown for seed.
Symptoms Infected plants are stunted, the heads a quarter to half as high as 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.