Macadamia – Husk Spot

Crop(s):          Macadamia

Disease(s):     Husk spot

Resistance Management Strategy for:

Group 1               Methyl benzimidazole carbamates (MBC);
Group 3               Demethylation inhibitors (DMI);
Group 7               Succinate dehydrogenase inhibitors (SDHI);
Group 11             Quinone outside inhibitors (QoI); and
Group 7 + 11      SDHI + QoI.

  1. If applying Group 1, 3, 7 or 11 fungicides, do not apply more than two consecutive sprays (including from one season to the next) of fungicides from the same group before changing to another group. This applies for fungicides sprayed alone or in tank mix with another mode of action.
      Group 1 Group 3 Group 7 Group 11 Group 7+11
    Maximum number of consecutive sprays when applied alone None None None None 1
    Maximum number of consecutive sprays when applied in mix with a different mode of action 2 2 2 2 2
    Maximum number of sprays per season 2 2 2 2 2
  2. The limit of two sprays per season for Group 7 and Group 11 applies to co-formulated products.
  3. The spray program should be considered and the strategy applied on a whole-orchard basis.


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.