an applicator for weedicide or other agricultural or horticultural treating liquid consists mainly of a swabbing brush having a multiplicity of pliant filaments , preferably of cruciform cross - section , trailing from a supply conduit to which the treating liquid is fed from a tank , the supply conduit which may be tractor - mounted being advanced over an area to be treated , so that the brush filaments with treating liquid running down them , are tailed over the area so that the liquid is applied directly to the area being treated . the swabbing brush , when tractor - mounted , is pivoted to swing back if encountering a tree or other obstacle , to be returned by a spring when the obstacle is passed .