Leaves on Watermelon, Pumpkin, and muskmelon turned black.
Last night, the temperature dropped down into the 50's for the first time - cold, but no real concern for frost or anything.
This morning when I went out to check the garden I found that most of my watermelons, pumpkins, and muskmelons which are spread out over a section about 75x75 ft, had sections of the plant that had turned black. Not brown or some other color, just black. (Though I did notice my cucumber leaves have a lot more yellow in them now).
I have no idea what would cause this. It would be a group of leaves off of a particular vine, sometimes the majority of an entire section of vine, etc. It seemed random as to where I would find it on a plant. I didn't seem to lose all of any plant. I checked these just yesterday, so all of this happened overnight. It's just the leaves that go black for the most part. The stems and vines are left kind of withered and pathetic looking, but not necessarily black. The leaves though, if affected, are always black. If I didn't know better, I'd suspect frost.
I also have no clue what would affect all of them at once like that. I'd wonder about my water source and contamination, except my peppers, tomatoes, corn, etc. don't show any real signs of issues.
A few more nights of this is all it would take for a total crop loss on my remaining melons.
Any clues as to what I might be looking at?