leaf curling

[GreginND]

The brown spotted leaf looks like black rot - a fungus. Are you employing a fungicide spray program?

 

[garymc]

And the pale color in the space between the veins and darker green close to the veins looks like a nutrient deficiency to me.

 

[GreginND]

Yes, I agree about the nutrient deficiency.

What is your soil pH? Have you had a soil test to test for nutrients?
I would also recommend getting a petiole test to see what nutrients the plants are lacking. Best time to take petiole samples is right around bloom and at verasion. So maybe plan for that next year.

 

[gordonm]

yes, I have been using a fungicide but over the last week after the rain its been just to windy to spray anything. The fungi haven't been a big problem, I only have fifty plants and everyday will walk down and cut off any leaves that show these signs. I may be able to spray in the next couple days but was wondering if it would do any good since whatever fungi have settled won't be effected by the spray now, would it?? My ph was good so I'll try the petiole test next year. I did use some merical-grow early on these two year plants, could that cause to much nutrients?

 

[garymc]

Miracle Grow is formulated so you can pour it directly on the foliage for foliar feeding if you mix it according to directions, so it's not likely to burn anything. There's probably some micro nutrient missing, and I'm guessing it's not one of those in Miracle Grow. I have to give my muscadines magnesium sulfate because they require a lot of magnesium. I don't know if other grapes have that requirement, so somebody else will have to make a guess. I use a little Ironite on mine also, just to make sure there aren't any missing minerals.