Potato – Target Spot (early Blight)

Crop(s):          Potato

Disease(s):     Target spot (early Blight)

Resistance Management Strategy for:

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

1. Limit the use of Group 2, 3, 7, 9 or 11 fungicides to periods when conditions favour disease development.
2. Do not apply more than six Group 2 sprays in one season. Apply no more than two consecutive sprays of a Group 2
3. Do not apply more than six Group 3 sprays in a season. Apply no more than two consecutive sprays of a Group 3 fungicide alone.
4. If three or fewer fungicide sprays for target spot are applied per crop, use only one spray containing a Group 7 fungicide. If four to six sprays are applied per crop, use a maximum of two sprays containing Group 7 fungicides. If seven or more sprays are applied per crop use a maximum of three sprays containing Group 7 fungicides. If used solo, apply Group 7 fungicides in strict alternation with fungicides from a different cross resistance group. If fungicides containing Group 7 are used in mixture, apply a maximum of 2 consecutive applications.
5. If three or fewer fungicide sprays for target spot are applied per crop, use only one spray containing a Group 9 fungicide. If four to six sprays are applied per crop, use a maximum of two sprays containing Group 9 fungicides. If seven or more sprays are applied per crop use a maximum of three sprays containing Group 9 fungicides.
6. Apply no more than two consecutive sprays containing a Group 9 fungicide.
7. Apply Group 11 containing fungicides preventively. Do not apply more than three foliar applications of a Group 11 containing fungicide per crop, no more than two consecutive Group 11 sprays per crop. If consecutive applications of Group 11 containing 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 containing fungicide is used again, either in the current or following season. When using a Group 11 fungicide in-furrow at planting, use a fungicide from a different group as the first foliar spray.
8. 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.