Grape – Downy Mildew

Crop(s):          Grape

Disease(s):     Downy mildew

Resistance Management Strategy for:

Group 4            Phenylamides (PA);
Group 11          Quinone outside inhibitors (QoI);
Group 21          Quinone inside inhibitors (QiI);
Group 40          Carboxylic acid amides (CAA); and
Group 45          Quinone outside inhibitor, stigmatellin binding type (QoSI).

  1. Apply all these fungicides preventatively. Group 4 fungicides should be applied before the first sign of oilspots or as soon as possible after an infection period.
  2. Mixtures – co-formulations or tank mixes with label rate of alternative mode of action.
  3. Apply a maximum of two consecutive applications of any one group.
  4. Start preventative disease control sprays using non-Group 4 protectant fungicides, typically when shoots are 10-20cm long. Continue spraying at intervals of 7-21 days depending on disease pressure, label directions and rate of vine growth.
  5. Limit the use of Group 4 fungicides to periods when conditions favour disease development. Always apply Group 4 fungicides in mixtures.
  6. Do not apply Group 11 consecutively when applying alone.
  7. Apply a maximum of 2 sprays per season of Group 11, including mixtures.
  8. Do not apply Group 40 as the last spray of the season.
  9. Only apply Group 40 for a maximum of 50% of the total number of downy mildew sprays.
  4 11 21+M1 40 45+40
Maximum number of consecutive applications 2 none 2 2 2
Maximum number of solo sprays None 2 3 2
Maximum number of sprays per season 4-mix 2 3 4-mix
Areas of higher agronomic risk mix mix N/A mix N/A

*Refer to Point 6

Content last updated: July 16, 2021

CropLife Australia’s Resistance Management Strategies provide a guide for crop protection product rotation through product groups. The strategies are a useful tool that supports farmers’ adoption of resistance management. All crop protection products must be handled and applied strictly as specified on the product label or APVMA permits.

These Resistance Management Strategies do not replace product labels. They are a guide only and do not endorse particular products, groups of products or cultural methods in terms of their performance. It is important to check with the Australian regulator’s (APVMA) product database for contemporary information on products and active constituents. The database can be sourced through

The information given in this strategy is provided in good faith and without any liability for loss or damage suffered as a result of its application and use. Advice given in this strategy is valid as at 16 July 2021. All previous versions of this strategy are now invalid.