See:
Fungicide Effectiveness as Seed Treatments for Cereal Diseases
Cause False loose smut is caused by the fungus Ustilago avenae (syn. = U. nigra) and may be easily confused with Ustilago tritici (see Barley-Loose Smut, below). However, U. avenae is slightly darker in color, infects plants shortly after seed germination, and cannot infect barley at the floral stage, unlike U. tritici. The two smuts can be accurately differentiated with laboratory tests.
U. avenae persists for years on or in barley seed. Disease is favored by drier soils and soil temperatures of 59°F to 70°F.
Symptoms Smutted heads emerge from the boot about the same time as healthy heads. The paper-like membrane that first encloses the dark brown spore mass soon ruptures, and wind blows spores to healthy heads.
Cultural control
- Use pathogen-free seed.
- Plant resistant varieties.
Chemical control Seed treatment.
- Charter at 3.1 fl oz/100 lb seed plus a dye. See label for rotation and reentry restrictions.
- Apron, Captan, or Thiram alone are ineffective.
Reference Mathre, D.E. 1997. Compendium of Barley Diseases. St. Paul, MN: APS Press