See:
Wheat (Triticum aestivum) - Common Bunt (Stinking Smut)
Cause Two fungi, Tilletia caries (formerly T. tritici) and T. laevis (formerly T. foetida), which are carried on seed or may survive a year in soil. Species of Agropyron (wheatgrass), Bromus (bromes, cheat grasses), Festuca (fescues), and Lolium (ryegrass) are susceptible as well as varieties of rye and wheat.
Symptoms No symptoms are readily apparent until the crop heads. Plants may be smaller and have more shoots. In infected seed plants, there is an absence of grain, all or part of the kernels are replaced by light brown smut balls filled with dark brown spore masses. When smut balls are crushed, a distinctive, foul odor is obvious.
Cultural control
- Plant grass in spring and promote vigorous growth the first summer.
Chemical control Use treated seed.
- Although registered, thiram when used alone gives only fair control of seedborne common bunt and is ineffective against soil-borne common bunt.