Pacific Northwest Plant Disease Management Handbook

Oats (Avena sativa)-Loose Smut

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Latest revision: 
March 2024
Image related to Oats (Avena sativa)-Loose Smut
Note the black sporulation of this fungus in place of seed heads.
Photo by Paul Koepsell, 1983.

See:

Fungicide Effectiveness as Seed Treatments for Cereal Diseases

Cause A fungus, Ustilago avenae, carried on seed.

Symptoms Powdery, black spore masses replace kernels and chaff. Black, smutted heads are easily distinguished as soon as heads emerge from the boot. Spore masses soon disperse and may not be evident at harvest.

Cultural control Avoid using contaminated seed.

Chemical control Seed treatments.

  • Apron or Captan alone are ineffective.
  • Raxil MD at 5 to 6.5 fl oz/100 lb seed plus a dye. See label for reentry restrictions.
  • Vitavax is registered but gives only fair control.

Pscheidt, J.W., and Ocamb, C.M. (Senior Eds.). 2024 Pacific Northwest Plant Disease Management Handbook.
© Oregon State University.

Use pesticides safely!

  • Wear protective clothing and safety devices as recommended on the label. Bathe or shower after each use.
  • Read the pesticide label—even if you’ve used the pesticide before. Follow closely the instructions on the label (and any other directions you have).
  • Be cautious when you apply pesticides. Know your legal responsibility as a pesticide applicator. You may be liable for injury or damage resulting from pesticide use.

Trade-name products and services are mentioned as illustrations only. This does not mean that the participating Extension Services endorse these products and services or that they intend to discriminate against products and services not mentioned.

H - Home garden packaging commonly available.     O - Acceptable in organic production.