Squash and pumpkin leaves wilted, look like dying...?

This is the first year we planted a garden. Some, not all, of the zucchini, squash, and pumpkins plants leaves look like they are dying. They are Yellow and wilting. My dad thought it was "blight" but I could not find any pictures of what this looks like. We do not use pesticides or fertilizers, 100% organic. The produce looks great, except for some bumps on the pumpkins and delicata. Are these safe to eat? What is the wilting?