I'm having some issues with some of my peppers as well.  I've been told that peppers require a lot of water.  I know that the ones that are having trouble are being watered with other plants that use a lot of water and may not be getting enough.   My community garden is on an automatic watering system and several of my pepper plants wilted while plants on either side of them were doing fine. Last year I had a great pepper crop with the same system but I had the peppers grouped together.  Next year I'm going to put my peppers all together so I can give them extra water and see what happens.  As for the melons I've never had luck with them so I gave up years ago. They really need a lot of water and sun. They also have a long growing season and we sometimes don't stay warm long enough for them to ripen.

Joseph