Current update on the fungicide sensitivity of Erysiphe necator (grape powdery mildew) in Europe

The aim of the study was to provide information on the fungicide sensitivity of grape powdery mildew (Erysiphe necator) to some of the modes of action used for grape powdery mildew control with a focus on Europe. QoIs: most samples analysed in this study showed high values of the G143A mutation, which leads to low field performance of QoIs. Therefore, QoIs have lost their strength on grape powdery mildew control. DMIs: European wide sensitivity studies indicated that DMIs are only slightly and differently affected by the mutation Y136F, being frequently detected in the pathogens’ cyp51 gene. Mefentrifluconazole was recently developed for grape powdery mildew control, and its sensitivity is even not affected by this mutation. APKs: resistance towards aryl-phenyl-ketones (APKs) has also been reported in various regions in Europe, and monitoring studies showed a heterogenous distribution from a sensitive situation towards populations with higher APK resistance. SDHIs: adaptation of Erysiphe necator to succinate dehydrogenase inhibitors (SDHI) is more recent and quite complex because different mutations can be found in the B and C-subunits of the SDH gene which have different effects on SDHIs. Different mutation pattern in different geographical regions have been found which could be the result of different SDHI use. Therefore, the implementation of resistance management strategies, including the use of various modes of action in alternation and mixture, are recommended for a sustainable disease management in grapes.