Grape disease

[Rakhal]

My Pinot Noir grapes have some sort of disease. Can any of you diagnose the problem from these photos? Is it powdery mildew? I sprayed with sulfur four weeks ago and they looked fine, but obviously it didn't help.

 

[Hazelemere]

next time you spray for powdery mildew add potassium bicarbonate to your spray. Powdery mildew attacks dry grapes. Once they get juicy the mildew may coat the skins but they won't crack. I have no idea why. "cracked skins" is common for powdery mildew. This may or may not be powdery mildew e.g. if I get it skins are white and canes have black splotches. Where are you located? Santa Rosa? What do your leaves and canes look like on these Pinot Noir?

 

[Rakhal]

next time you spray for powdery mildew add potassium bicarbonate to your spray. Powdery mildew attacks dry grapes. Once they get juicy the mildew may coat the skins but they won't crack. I have no idea why. "cracked skins" is common for powdery mildew. This may or may not be powdery mildew e.g. if I get it skins are white and canes have black splotches. Where are you located? Santa Rosa? What do your leaves and canes look like on these Pinot Noir?

Sebastopol California. The leaves are turning yellow already and the canes do have some black splotches.

 

[Hazelemere]

Sebastopol California. The leaves are turning yellow already and the canes do have some black splotches.

powdery mildew if the canes have black splotches. Soak your vineyard with powdered sulphur and potassium bicarbonate in a spray.

https://www.amazon.com/Potassium-Bi...&sprefix=potassium+bicarbonate,aps,301&sr=8-1