I have read that using caliente mustard as a green manure crop can help “fumigate” soil where onion white rot is present. Does anyone have any experience of growing this as I lost a lot of my onions to white rot last year.
Good question and I would add, in a no dig way? Because the advice for growing it has the usual finale of “dig it in”. However if its the roots doing the fumigating, one could just cut off the tops, at whatever stage.