Common bunt (Covered smut)

Common bunt/Covered smut

Description

• Bunt is generally well controlled by seed treatments
• However, bunt outbreaks can occur in crops where seed treatments have not been used, are not used every year or where inadequate coverage of the seed has occurred. 

Symptoms

• Strong putrid fishy smell emitted from grain
• Grains of wheat are replaced by a mass of bunt spores, a 'bunt ball'  
• Bunt infected plants are usually stunted
• At maturity, bunted heads are darker in colour and have splayed glumes 

Damage

• Grain Trade Australia's commodity standards have a nil tolerance for bunt in all grades of wheat

Control

Seed treatments are extremely effective in controlling bunt. However, seed treatments need to be applied every year, and a good coverage of grain is essential to prevent infection. Bunt spores germinate most rapidly in cool temperatures, so sowing wheat early into warmer soils can be an effective preventative measure.

Links and Resources

DAFWA - Farmnote 456 Information on cereal seed dressing and in-furrow fungicides used for common bunt, disease diagnosis, cautions, and further contacts. Pager amended 2011.

DEPI VIC - Covered Smut The section detailing common bunt of wheat gives an introduction, symptoms, life cycle, recieval standards, and control methods. Published 2007, updated 2013.

DEPI VIC - Identification and management of field crop diseases in Victoria. Bunt of wheat Introduction, what to look for , disease cycle, recieval standards, and control. Published 2012.

Victorian winter crop summary - common bunt Table 6: Wheat disease guide. Page 11. Causal organism, symptoms, occurrence, inoculum source, and control. Updated annually.