Is this from a pest or too much water?

[exarkun]

On my 2nd year marquette vines I noticed one of my vines had this the other day, now 3 do.

We've had a LOT of rain here in the past few weeks, so maybe it is water related?

Or is it from a pest?

 

[exarkun]

Better picture of the damage...

 

[grapeman]

It is probably anthracnose. Besides the leaf having the proper look for it there are also pitted lesions on the shoot. It could be phomopsis, but the leaf isn't right for that and not enough lesions.

 

[exarkun]

Looks like you are correct once again.

On one of my vines pretty much all the leaves are affected. Should I cut it all down to the ground, or treat it with anti-fungicide that prevents anthracnose and hope it lives?

TYIA

 

[grapeman]

Treat it this year and see if it grows out of it. You can prune out most of the affected wood during the next dormant pruning.