Black spots on leaves, struggling vines

[johngg123]

Does this look like any sort of problem or identifiable disease? The grapes are zin and pinot noir, in southern california costal region. They are first year grafts on 101-14. I have grapes in other parts of the property which are doing great. Makes me think this is perhaps bad soil or water stress?

Note we have had very hot humid weather (80 degrees) past few days which is rare for this area.

Thanks!

 

[lawrstin]

That looks like birds eye (anthracnose). Remove and destroy.

 

[djrockinsteve]

I get this on mine too. I think it's just the heat and lack of water. Turn a few leaves over and look carefully at the dark areas. If its insect related you may see some.

Since its contained at the edges makes me think its not insect or fungal but I am not knowledgable in this area.

Hang in there others will post about it.

 

[johngg123]

lawrstin, Based on some google image searches, I think it probably isn't anthracnose. I'm not seeing anything like that in the vineyard.

I'm going to throw out another possibility.. nutrient deficiency? Possibly K or P or B?

 

[grapeman]

I would agree that it isw probably nutrient related which can be related to heat stress along with water deficit. More water might allow more uptake of the needed nutrients.

 

[Duster]

My concords that was planted this spring are doing the same thing as well, this summer in my neck of the woods has been just the opposite of yours, cool and wet. I gave them a couple shots of miracle grow and that seem to make it worse, since I have stopped (last dose about 3 weeks ago) they seem to be getting better. I'm still not sure what it is.
New leaves don't seem to have it but within a week or so of reaching full size they seem to develop the same spots. As you mentioned, mine too don't seem to be as vigorous as I think they should but they are still growing. All I can do is keep an eye on them for now.

 

[lawrstin]

The leaf looks very green. I imagine that it will begin to curl soon while it is still green.