Powdery mildew in barley and wheat

Powdery mildew is currently under effective control in the southern region when treated seed/fertiliser is used and resistant cultivars are grown. However, care is needed to maintain this situation to minimise the risk of the pathogen developing into a damaging threat to the industry.

Key points

• Powdery mildew is a windborne fungal disease that survives between seasons on stubble, plant residues and volunteers.
• The best means for controlling powdery mildew is by avoiding more susceptible wheat and barley varieties.
• All barley crops other than those rated Resistant (R) should be treated with a fungicide at seeding.
• If powdery mildew is allowed to develop in crops, there is a serious risk of fungicide resistance developing as well as loss of resistance in current and future varieties.
• Using different chemistries reduces the risk of resistance developing. If powdery mildew is detected in crops, use a QoI/DMI (strob/triazole) mix for the first foliar spray. If a second spray is required, use a DMI (triazole).