Determination of the efficacy of some fungicides against grapevine powdery mildew

In this study, the efficacy of the active ingredients of the fungicides Boscalid+Pyraclastrobin, Isopyrazam and Triflumizole+Cyflufenamid was determined against grapevine powdery mildew (Erysiphe necator Schw.) under field conditions. The trials were conducted in the Ahmetağa neighborhood of Sarıgöl district of Manisa province in 2017 and 2018. It was determined that the efficacy of the tested fungicides was 8.0-94.3% and 3.9-90.9% in 2017 and 2018, respectively. In both years, the highest and lowest effective fungicides were Boscalid+Pyraclastrobin (60 g/100 l water) and Triflumizole+Cyflufenamid (12,5 g/100 l water), respectively. As a result of the trials, it was found that fungicide applications did not cause a positive or negative effect on yield (cluster weight) values of cv. Sultani Seedless. In conclusion; according to our findings, 60 g/100 l water dose of Boscalid+Pyraclastrobin, which is not registered against grapevine powdery mildew, is considered to have the potential to be registered.