[RWebb]

go remove each leaf with mold on it and put it in the trash (NOT the compost)
- powdery mildew survives composting

they also tell vintners to clear away any undergrowth (tho one top Or. Pinot producer told me he uses grass at the base of his vines to modulate their development - slow them down when > 3 years old)

you are super clear down there & doesn't look all that shady, so not sure why you are having mold probs. - call your county agric. extension office and get advice from them