Summary.Following the discovery by J. G. Elliott and T. I. Cox in 1961 of the specific selective properties of certain methylmercapto triazines for the control ofChenopodium albumin kale (Brassica oleraceavar.acephala), extensive investigations of this subject were carried out by the authors in 1962. The work resulted in a practical recommendation to British farmers in 1963.2‐Methylmercapto‐4‐methylamino‐6‐isopropylamino‐1,3,5‐triazine (G 34360) showed significantly higher selectivity than simetryne. The dose giving an optimum degree of selective control varied according to humidity and moisture. A dose of 4 oz/ac was sufficient for kale grown under moist conditions, while 6 oz/ac was required under condition of low rainfall and atmospheric humidity.The development stage of the kale was critical and the herbicide was sufficiently safe only when applied after the kale had three leaves. No differences in response were observed between marrow‐stem and thousand‐head kale. Volume rates from 10 to 80 gal/ac were compared, but no clear differences were found.Destruction sélective deChenopodium albumL. dans le chou fourrager avec les mét