Strawberry – Powdery mildew

Crop(s):          Strawberry

Disease(s):     Powdery mildew

Resistance Management Strategy for:

Group 3              Demethylation inhibitors (DMI);
Group 7              Succinate dehydrogenase inhibitors (SDHI);
Group 7+11       SDHI + QoI;
Group 7+12       SDHI + phenylpyrroles
Group 11           Quinone outside inhibitor (QoI);
Group 19          Chitin synthase inhibitor;
Group 21           Qionone inside Inhibitor (QiI); and
Group U6           Phenyl-acetamide.

1. Apply a program of protectant fungicides from early crop establishment and maintain a regular spray program throughout the crop growing cycle. If weather conditions favour powdery mildew development, use a Group 3 or 11 fungicide.
2. Do not use the same fungicide group as the last application on runner production and the first application to in-field fruit production.
3. Do not use Group 3 or 19 fungicides as eradicants (once symptoms are visible).
4. Do not apply more than four Group 3 sprays per season.
5. Do not apply more than two consecutive sprays of Group 3 or 19 fungicides, including from one season to the next.
6. If applying Group 7 fungicides (including 7+11 or 7+12), do not apply more than two consecutive sprays before changing to another group.
7. Do not apply more than three Group 7 sprays per season. If consecutive sprays are used, then use the same number of sprays of an alternative group before using another Group 7, including sprays in consecutive seasons.
8. Apply Group 11 or U6 fungicides preventively.
9. Do not apply consecutive sprays of Group 11 or U6 fungicides, including from one season to the next.
10. If three or fewer powdery mildew fungicide sprays are applied per crop, use only one spray containing a Group 11 fungicide. If four to six sprays are applied per crop, use no more than two sprays containing a Group 11 fungicide. If seven or more sprays are applied per crop use a maximum of three sprays containing a Group 11 fungicide. Do not apply more than three Group 11 sprays per season.
11.  or 19
12. Do not apply Group 19 fungicides more than six (6) times per season, or more than 50% of the total number of fungicide sprays.
13. Apply Group 21  as a protectant spray only.
    • Do not apply more than two (2) consecutive sprays or more than three (3) times per crop season.
    • Exposure to Picolinamide (or any other Group 21 containing product) should not exceed thirty-three percent (33%) of the total period of protection needed per crop.
    • Picolinamide applications are to be made preventatively and so more than two (2) times in sequence before applying a fungicide with a different mode of action
    • Continue alternation of fungicides between successive crops.
14. Do not apply more than two Group U6 sprays per crop.
15. 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.