we have started spraying with round=up but i think pastur would do it.you must realise that ragwort is at its most dangerous stage when it is dying so do not put anything into the field until it has completely gone, which maybe more than six weeks. If you dig it out you may leave some roots which will regrow.I hate the stuff, we have some paddocks that we deep harrowed and reseeded last year which means we disturbed the seed and it is now growing, so we are spraying to kill it.