Stone fruit – Blossom blight, brown rot

Crop(s):          Stone fruit

Disease(s):     Blossom blight (Monilinia laxa), brown rot (M. fructicola)

Resistance Management Strategy for:

Group 2           Dicarboximides;
Group 3           Demethylation inhibitors (DMI);
Group 7           Succinate dehydrogenase inhibitors (SDHI);
Group 7+11     SDHI + Quinone outside inhibitors (QoI);

Group 9           Anilinopyrimidines (AP); and
Group 11         Quinone outside inhibitors (QoI).

  1. If applying Group 2, 3, 7, 11 or 7+11 fungicides, do not apply more than two consecutive sprays of fungicides from the same group before changing to another group, this includes the last application made in-field from one season to the next.
  2. Do not apply more than three sprays of a Group 7, 9, 11 or 7+11 fungicide per season. Alone, tank mixed or co-formulated all count to total. If group 7 applied alone, apply Group 7 in strict alternation with fungicides from a different cross-resistance group.
  3. When mixtures are used for Group 7 resistance management, applied as tank mix or as a co-formulated mixture, the mixture partner should provide satisfactory disease control when used alone on the target disease and must have a different mode of action.
  4. Always apply Group 7 fungicides as per label instructions and use preventatively.
  5. If consecutive sprays of fungicides from the same chemical group are applied, they must be followed by at least the same number of sprays from an alternative chemical group, before returning to the original group.
    2 3 7 9 11 7+11
    Maximum number of consecutive sprays when applied alone 2 2 2 2 2 2
    Maximum number of consecutive sprays when applied in mix with a different mode of action 2 2 2 2 2 2
    Maximum number of sprays per season 3 3 3 3 3 3
  6. A post-harvest treatment should also be counted as an application.
  7. The last blossom blight spray and the first pre-harvest brown rot spray should be regarded as consecutive applications.
  8. The spray program should be considered and the resistance management strategy applied on a whole-orchard basis.
  9. No specific resistance management strategy has been developed for low-risk fungicides, including those in Group M and BM. These products should be included in a management strategy as per label recommendations.

Content last updated: June 30, 2022

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 30 June 2022. All previous versions of this strategy are now invalid.