Keep your eye out for squash vine borers as well, they will cause leaves to wilt also...

When my zukes start getting PM, I also cut off the badly affected leaves, give the plants a shot of fert(to support the new growth)and spray the plant with fungicide to slow down the PM. It really helps to get them to the end of the season for me.

I think that removal is only half the key, you still will need to spray something to keep the newer growth clean. The organism infects before it's visible.

I can't remember what I sprayed with a few years back, but it worked well. Possibly something along the lines of Immunox or Daconil -- I REALLY can't remember.

The other approach, though, is to start new plants around July 1st and set out.

Honestly, though, being summer squash, I just get sick of them and frankly don't care after about the middle of August, and they do usually hold on long enough to produce the odd squash or two going into the fall for fresh eating.

Upon checking the zuke plants earlier this morning, I saw that they still looked good! But that is a good idea to start some new zuke plants about July 1st or maybe on the 4th of July to make it easier to remember! I did spray them w/ some fungicide but should probably redo w/ the spray cuz I took off most of the affected leaves. I thought some of the leaves had early blight, also, which could easily affect some of my other veggies that are currently healthy! I am happy w/ the decision to have done this and it gave new life not only to the zukes but also to some things that were getting swallowed up by those big guys! Zukes seem to like to take over the garden! lol!
Now I'm working on the pumpkin to avert as much of the powdery mildew on them as possible also!