It looks a bit like scab. I'm no expert on diseases though-can't imagine a bit of neem spray or an organic skim milk/water mix would hurt though...

Thank you Stellabee! I will try the skim milk and water mix. I really hope it works. It has finally stopped raining and there is no rain in the forecast for another week so I hope this will help the cukes recover.

Looks like angular leaf spot, or a leaf spot of some kind. It's a type of fungus so the milk spray should help.