Barley – Powdery mildew

Crop(s):         Barley

Disease(s):    Powdery mildew

Resistance Management Strategy for:

Group 3                Demethylation inhibitors (DMI);
Group 5                Amines (morpholines);
Group 7                Succinate dehydrogenase inhibitors (SDHI);
Group 7 + 3        SDHI + DMI;
Group 11 + 3      Quinone outside inhibitors (QoI) + DMI;
Group 11 + 4      QoI + phenylamide (PA); 
Group 13             Aza-napthalenes; and
Group 11+7+3    QoI + SDHI + DMI.

1. Fungicides should be used preventatively or at first sign of disease. If disease is established within the canopy, fungicides may not produce optimal results and there is high chance of selection for fungicide resistance. In high risk disease environments, integrated management approaches should be used to reduce fungicide resistance risk including the removal of stubble, control of green bridge volunteers and the use of resistant varieties. Monitor if conditions favour disease development and reapply an appropriate fungicide from 21 to 28 days after first application. Use the higher label rate ranges where conditions favour disease development.
2. Do not apply more than two applications per growing season of Group 3, 5, 7 (7+3, 11+7+3), 11 (11+3, 11+7+3 or 11+4) or 13 containing products. This includes in-furrow or seed treatments that have activity on powdery mildew. Combinations of in-furrow and seed treatment are counted as one application.
3. Use Group 13 products in mixture with an effective partner or alternate with fungicides of a different activity group. Always apply in mixture with a curative fungicide where disease is established. Where applied alone, only use as a protectant (preventative) treatment.
4. Do not apply consecutive applications of Group 11 containing products. This includes in-furrow i.e. If a Group 11+4 fungicide has been used in-furrow at planting, the first foliar fungicide spray must not contain a Group 11 fungicide.
5. If a Group 7 seed treatment has been used with foliar activity (as determined by label claims), the first foliar fungicide applied must not contain a Group 7 fungicide.
6. Group 7 foliar fungicides must always be in a co-formulation or in mixture with a registered mixing partner with a different mode of action, with no known resistance.
7. Minimise use of Group 3 fungicides which are known to have compromised efficacy due to resistance.