Strange splitting on the bulbs of my kohl rabi.
Some are splitting horizontally, others vertically. They are a bit bigger than golf balls at the moment (or rather they were). It looks almost as if they've been vandalised with a sharp knife. Not all of them are suffering this way. They have been watered moderately along with pumpkin, cauliflowers, and dwarf beans in the same general area, all of which are doing OK.
Any ideas what might be causing it, or what I can do to rescue them? ???