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 11 + 3

Group 21

QoI + Demethylation inhibitors (DMI);

Quinone inside inhibitors (QiI);

Group 40 Carboxylic acid amides (CAA);
Group 45 Quinone outside inhibitor, stigmatellin binding type (QoSI);
Group 45+40 QoSI + CAA; and
Group 49 Oxysterol binding protein homologue inhibitors (OSBPI).


  1. 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.
  2. Group 4 fungicides should be applied as soon as possible after an infection period, and before the first sign of oilspots. Limit the use of Group 4 fungicides to periods when conditions favour disease development. Always apply Group 4 fungicides in mixtures.
  3. Group 49 fungicides should be applied prior to infection and only in mixtures with effective fungicides applied at an effective rate from a different cross resistance group. The mixing partner should give effective control of downy mildew at the rate and interval selected. A maximum of two Group 49 applications may be made per season. Only apply Group 49 for a maximum of one in every three sprays of the total number of downy mildew sprays. A Group 49 application must be followed by at least two applications of a different group(s) before being reapplied.
  4. Fungicide mixtures are defined as co-formulations, or tank mixes at label rate of an alternative mode of action.
  5. Apply a maximum of two consecutive applications of Group 4, 21, or 40 containing fungicides.
  6. Do not apply Group 11 (including Group 11+3) consecutively when applying alone.
    1. Apply a maximum of two sprays per season of Group 11 (including mixtures) Group 45+40 and Group 49.
    2. Do not apply a spray containing Group 40 as the last spray of the season. Only apply a spray containing Group 40 a maximum of 50% of the total number of downy mildew sprays.
    3. Apply a maximum of three Group 21 containing sprays per season, and a maximum of two consecutive sprays
    4 11,
    11+ 3
    21+M1 40, 45+40 & 40+M3 49
    Maximum number of consecutive applications 2 none 2 2 none
    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 mix

    * Refer to points 7 &8
    N.B. Consecutive sprays include mixture formulations



Content last updated: June 26, 2024

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 26 June 2024. All previous versions of this strategy are now invalid.