Grape – Grey Mould (Botrytis bunch rot)

Crop(s):          Grape

Disease(s):     Grey mould (Botrytis bunch rot)

Resistance Management Strategy for:

Group 2             Dicarboximide;
Group 7             Succinate dehydrogenase inhibitors (SDHI);
Group 7+3        SDHI + Demethylation inhibitors (DMI);
Group 7+12      SDHI + phenylpyrroles;
Group 9             Anilinopyrimidine;
Group 9+12      Anilinopyrimidine + Phenylpyrroles;
Group 11            Quinone outside Inhibitor (QoI);
Group 11+3       QoI + Demethylation inhibitors (DMI); and
Group 17           Hydroxyanilide.

  1. Always use an integrated disease management approach to grey mould management in vines. Manipulate the bunch zone microclimate to reduce humidity and enable rapid drying of wet bunches. Always aim to reduce spore load, flower and fruit infection and limit regrowth of latent infections and disease spread by timely fungicide application in an IDM approach. Use registered fungicides at label rates from as many different mode of action groups as possible when needed.
  2. Apply all these fungicides as protectants before the first sign of disease.
  3. Consecutive applications include from the end of one season to the start of the next.
  4. Varying the number of fungicides applied targeting Botrytis changes the relative resistance risk to any one fungicide group. When three or fewer sprays are applied, it is recommended that three different groups of fungicides are used (see table below). When four sprays are applied, try to use 3 or 4 different groups of fungicide.
  5. If a Group 11 or 7 fungicide is used solo, it should only be used in strict alternation with fungicides from a different mode of action group.
  6. Do not apply more than two consecutive sprays from the same fungicide group, for any Group 2, 7, 9 (including combinations with Group 12) 11+3, 12 or 17 fungicide, including from the end of one season to the start of the following season.
  7. If two consecutive applications of Group 11+3 fungicides are used, then they must be followed by at least the same number of applications of fungicide(s) from a different group(s) before a Group 11 (including combinations with Group 3) fungicide is used again, either in the current or following season.
  8. If resistance to a fungicide group has been detected within a region, only use that fungicide group in mixtures or in strict alternation with fungicides from a different cross resistance group. A fungicide group that has been applied as the final application of the season should not be the first fungicide in the following season.
  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.
  Maximum recommended number of sprays which can contain Group:
Total number of Botrytis targeting sprays   2 7 (Incl. 7+3, 7+12) 9 (Incl. 9+12) 11 (Incl. 11+3) 12 (Incl. 7+12, 9+12 17
1 1 1 1 1 1 1
2 1 1 1 1 2 1
3 1 1 1 1 2 1
4 2 2 2 2 2 2
5+ 2 2 2 2 2 2

URL: https://croplife.org.au/resources/programs/resistance-management/grape-grey-mould-bunch-rot-2-draft/
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 www.apvma.gov.au

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.