See:
Fungicide Effectiveness as Seed Treatments for Cereal Diseases
Cause The fungus, Ustilago hordei. Spores can overwinter on barley seeds or in soil. Infection is favored by high soil moisture over a wide range of temperatures.
Symptoms Kernels in heads of infected plants are replaced by masses of dark brown smut spores. When infected heads emerge, a whitish or gray membrane enclosing spore masses will split and may release some spores. Spore masses are further broken up during harvest, scattering spores on grain. Frequently, masses of spores remain intact and appear in harvested grain.
Cultural control
- Plant tolerant or resistant varieties.
Chemical control Seed treatments can give excellent control.
- Charter at 3.1 fl oz/100 lb seed plus a dye. See label for rotation and reentry restrictions.
- Dividend Extreme at 2 to 4 fl oz/100 lb seed for spring barley. Do not graze green barley forage until 30 days after planting. See label for reentry restrictions.
- Although Captan, mancozeb, and Thiram are registered, they give only fair control.
- Apron alone and products with imazalil are ineffective.