Do you know this grapevine disease

It is powdery mildew. It is one of the scourges that can jeopardise a harvest. It is generally rarely found in the Gironde, as it prefers warm, dry climates. However, the first traces of it have appeared this year. The photos were taken on a table grape trellis at Château Magence. Powdery mildew appeared in the Gironde around 1851, inadvertently imported from the Americas. It destroyed harvests over several vintages, particularly in the Graves. It is even said that this is certainly the reason explaining the absence of Graves wines from the 1855 classification. As the vines were severely affected, the harvests were not of high enough quality to be submitted to the classification. Without powdery mildew, the history of Graves wines would undoubtedly have been quite different.