In my 50 years of farming and plant management, I've never seen mold, fungus, or mildew growing on crop plant leaves.
When I water, it's always just after sunset. Though we have to be in a drought condition before I water anything.
I put my rain gauge in the garden and let the sprinkler fill it to 3" once a week, maybe ten days if the forecasters
call for any rain that doesn't develop. Is there areas in the U.S. where this is more prevalent that others??