So this is the 5th year that my grapevine has been growing and every year I get a really good amount of healthy grape growth in the beginning but almost all of them shrivel up and die before they fully ripen to a the purple wine grape that they are supposed to. This has happened every year around this time (July) and even earlier. I am growing them on Long Island, NY. Please look at the pictures, you will notice how they start to turn purple but then look like they rot out and then finally they shrivel up and fall off. They only spray I use is a very light spraying of stylet oil (this year I only applied once). My soil is very alkaline so this year I attempted to make it a little more acidic by adding holly tone. Any advice would be greatly appreciated, thank you!