Nutrient shortage ?

This is the nutrient defficiency I am seeing on my grapes. It's scattered throughout the plant but mostly on the leaves at the end of the longest vines. Leaves have green veins, and are pale overall.

I am wondering if the plant at this late-season stage is funnelling it's leaves' reserves into making fruit ?

Maybe this condition results before leaves fall off? If nutrients and reserves in the leaves and stems get directed into fruit production. So maybe this is normal ?

Advanced Nutrients makes that product called Overdrive specifically to feed the plant's high need for nutrition during the fruit bearing stage. I wonder if it prevents this from happening ? I found some reading about it here:

http://www.advancednutrients.com/advancepedia/product.php?productID=41&catID=18

Or, I wonder if this would have been avoided if I had carried on using Colossal Bud Blast and B52 for longer..?

However my fruit yield is almost insane !