Hi all, first time growing kale. No major problems up until I suddenly got this very white edge deterioration happening on one of my plants.. What the heck is it? I have been dealing with what I assume are minor caterpillar issues - they eat these little squiggly lines on surface of the plant rather than eating entire leaf itself. I got some diomecteous earth food grade powder that I sprinkled all over to deal with that, and seemed to be working. Now suddenly, in a span of 24-48 hours max, I come outside to see this entire white edge thing happening around large portions of the kale leaf. Is DE bad for kale? We had some rain and intense wind so only thing I could think was maybe DE washed and smeared over the leaf, but this white stuff actually is the kale itself changing color, white part is dry and wrinkly.

A fungal problem? If so which one that affects kale specifically? Also should I remove all leafs that look like this and how do you prevent this from spreading?

Thanks,
-L