Managing barley loose smut infection

Loose smut in hindmarsh barley

Image source: Andrea Hills, DPIRD

Loose smut was observed in barley crops in Victoria, South Australia and southern New South Wales, particularly Hindmarsh, LaTrobe and Spartacus in 2017. Smut infections were found in crops that had registered seed treatments applied to seed and good coverage achieved. This was because these barley varieties are very susceptible to loose smut which increases the risk of infections occurring.

Application of an effective seed treatment with good coverage to seed prior to sowing is very important for control. Seed treatment tests conducted by SARDI have shown that products containing just triadimenol provide only about 50% control of loose smut in Hindmarsh. Products containing flutriafol and tebuconazole or a low rate of Rancona Dimension (80 mL) allow some infection to persist in crops. If using Vibrance or Rancona Dimension, the higher rates set for rhizoctonia control should be used. The most effective control was provided by products containing carboxin and the SDHI fungicides Vibrance and Evergol Prime. Be sure to use the highest label rates, as these products may not be 100% effective in all situations. For more detailed information consult the SARDI Cereal Seed Treatment Guide.

Infection occurs when spores released at flowering infect florets and the developing grain in the head. This means that next years seed is infected prior to sowing. Growers should therefore be cautious of using infected seed to sow in 2018. Once a crop is infected with loose smut, there is nothing that growers can do to stop infections and further spread. Be aware that new seed can also be infected, so make sure that seed treatments are used.

Further information on loose smut

GRDC Project Code: DAV00129

Acknowledgements

Luise Sigel and Grant Hollaway, Agriculture Victoria

 

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