>>1076364When I grew icicle radishes, they would have some nice seed pods that were great in stir fry. However, I had to pick them very immature. If they were a bit older they because oddly woody and stick-like when heated, but were okay at that stage when eaten raw. I've never heard of using a daikon (Raphanus sativus) for a winter cover crop until your post. Kind of odd they are selling them as "nitro" radishes since they are not nitrogen-fixing. I guess you'd need to use nitrogen-fixing rhizobial bacterial inoculant it aid in that. It seems these are also called "groundhog radish/forage radish/oilseed radish...Tillage Radish™". lol
https://en.wikipedia.org/wiki/Daikon#Agricultural_useReport back on how well they work out for you.
My biggest taproot plant I'm trying out this year is burdock/gobo/niu bang zi (Arctium sp.) from seed of local common burdock plants (Arctium minus; googled pic 2nd year plant). I'd like to get some greater burdock (Arctium lappa) since t he taproots are larger in first year plants, but there aren't any in this area it seems (common burdock has hollow leaf stems and greater burdock doesn't.) If they prove to be tasty, I may order some greater burdock seed down the road.