Flag Smut

Flag smut


  • Historically flag smut was an important disease of wheat in Victoria
  • In recent years this disease has been controlled with the use of resistant varieties and treatment of seed with fungicides


  • Long, black raised streaks on the leaves, leaf sheaths, awns and stems
  • Mass of powdery grey-black spores which easily rub off onto a finger
  • Infected stems are stunted, distorted and seldom produce ears
  • Infected leaves do not expand fully and remain rolled and twisted
  • Not all tillers on a plant will exhibit symptoms


  • Losses from flag smut of wheat, when the disease occurs, are generally in the range of 5 to 20 per cent, however complete crop losses are not unknown


The regular use of fungicide seed treatments will control this disease. Avoiding the more susceptible wheat varieties will also help to control flag smut. Following a flag smut outbreak it is important to rest the affected paddock from wheat for several years and source clean seed.

Links and Resources

DAFWA - Farmnote 465. Flag smut

Page contains information on cereal seed dressing and in-furrow fungicides used for flag smut, disease diagnosis, cautions, and further contacts. Page updated 2011.

DEPI VIC - Flag Smut

The section detailing flag smut of wheat begins with a brief introduction, symptoms, life cycle, and control. Published 2007, updated 2013.

Victorian winter crop summary 2014 - Flag smut

Table 6: Wheat disease guide. Page 11. Causal organism, symptoms, occurrence, inoculum source, and control. Updated annually.