cucumber leaves turning yellow, brown

[worldharmony]

My cucumber plant is producing cucumbers, but after our first harvest we noticed the leaves dying. They get large yellow splotches, then turn brown. What is happening? What can we do to resolve this problem?

[The Helpful Gardener]

Very suceptible to mildew, but mine went through the same sort of thing this year even as I sprayed milk and it turns out the roots were getting chewed out by voles . Pics sure would help...

HG