CropAlert – Fungicide Resistance July 2021

CropAlert – Fungicide Resistance July 2021

Be on the lookout for net form of net blotch in barley crops this growing season. Severe infection of this potentially damaging foliar disease have been reported in commercial crops of Spartacus CL which was previously resistant. The levels observed indicate the arrival of the more virulent strain observed in South Australia in 2020. This strain is also resistant to some fungicides, such as the seed treatment fluxapyroxad (Systiva) and foliar fungicide propiconazole. So be on the lookout for crops treated with either of these fungicides and ensure the expected control has been achieved.

Growers and agronomists are encouraged to monitor crops for signs of fungicide resistance. Suspected instances of fungicide resistance can be reported to the Horsham Pathology team or the fungicide resistance group at Curtin University.

Follow the five steps below to reduce the risk of fungicide resistance:

  1. Avoid susceptible varieties
  2. Rotate crops – use time and distance to reduce disease carry-over
  3. Use non-chemical control methods to reduce disease pressure
  4. Spray only if necessary and apply strategically
  5. Rotate and mix fungicides/Modes of Action groups


Horsham Field Crop Diseases research group (Agriculture Victoria)

For further information contact the Horsham Field Crop Diseases research group

Ph: (03) 4344 3111

Email: [email protected]


Fungicide Resistance group (Curtin University, Western Australia)

For resistance testing contact the fungicide resistance group at Centre for Crop Disease Management

Email [email protected] or [email protected]


Further information

Further fungicide resistance management information can be found at

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