Need Help with Mooli (Daikon) | New Gardeners | Commercial Hydroponics farming

Hi

I had planted Daikon ( Mooli) and the leaves got pretty big but when I harvested the plant I found below all leaves there was a soil like layer on all the leaves so I suspect some disease or pest but have no idea what it is ?

Now all the other little Daikon leaves that were there in the pot have the same sediment. Is there a way to save it . There were also a few mint leaves that are growing in the same pot.

Need organic option as well to ward off pests n disease. I have spinach , salald leaf , coriander , mint , carrot on my terrace.

Cheers