I have grapevines all down the side of the house, growing on a big trellis over the "driveway."

The leaves get brown holes, then gradually go totally brown, and underneath there is a white powder. I've thought of rust. It does seem to pass from one leaf to another. So I removed all the leaves about a month ago. But then I went on vacation and now it's so widespread that I don't feel like doing anything about it: overwhelming!

Anything I can do?

Is it rust or not enough water or not enough sunlight?

It's not pretty!