How Can I Keep My Grapes From the Rusty Leaf Problem
I used a natural weeb oil that killed the grapes.
I use a product called Green Cure to keep things like powdery mildew, rust and black spot off my roses, pumpkins, cucumbers and such. I see no reason why it would not work very well on your grape vines. Here is a link for you on this product so you can check it out;