Doff® Weedout Extra Tough Weedkiller Concentrate MAPP 18335 contains 90g/l glyphosate in a soluble concentrate. A systemic herbicide that kills the foliage and plant roots of unwanted vegetation.  Weed control is initially seen as a yellowing of the leaves which die back after a few days or can take up to 4 weeks after application. Each pack contains two 80ml sachets which are to be mixed into 800ml of water to treat over 30m².