Marquette cluster die-off

[bilbo-in-maine]

Anyone have any insight in to why a small number of Marquette clusters wither? The stems appear to pinch off and everything below dies. Only happening on Marquette.
Sorry, can't get the photos to rotate but you can see the issue.

 

[grapeman]

This is a fairly widespread phenomenon this year. I have some here and others locally do also. I spoke with a friend just this AM from Vermont and he is having the same problem there. I'm wondering just what it is since I don't believe it is black rot, even though the grapes eventually shrivel and mummify.

Anyone know what it is?

 

[bilbo-in-maine]

Dang Rich, I thought for sure you would explain all! How odd that you're seeing it too. It's definitely not the look of black rot - I know it well (mancozeb to the rescue.)

 

[Pat57]

It almost looks just like damping off disease, but that only affects very young seedlings. Never seen anything like that on older stems?