Rain and Grapevine Diseases

We have had so much rain that we are concerned about grapevine diseases as mentioned in the Compendium of Grape Disease:
For example, prolonged periods of wet weather favor Botrytis bunch rot, downy mildew and other fruit and leaf spot diseaes. Phomopsis cane and leaf spot disease can cause devastating epidemics in protracted periods of wet, cool weather.¹
One of the online publications that I keep referring to is the Identification Guide to the Major Diseases of Grapes.² Although it is a publication emanating from Canada, the photos are very helpful:

The publication provides information on the symptoms, epidemiology and weather conditions conducive to the appearance of the disease. There is also a side by side comparison of the similarities between powdery and downy mildew and then a series of photos that show the differences with powdery mildew. It also advises careful scouting in the vineyard and provides a template for scouting notes.

Reference:
1. Roger C Pearson and Austin C. Goheen, Compendium of Grape Diseases, APS Press.
2. Odile Carisse, Agriculture and Agri-Food Canada, Réjean Bacon, Agriculture and Agri-Food Canada, Jacques Lasnier, Co-Lab Recherches et Développement and Wendy McFadden-Smith, McSmith Agricultural Research Services, Identification Guide to the Major Diseases of Grapes.