Abstract: Vehicle-borne apparatus for spraying liquid completely around immoveable upstanding objects such as trees or poles. The apparatus comprises an articulated boom having a pair of normally aligned, linear members. These members are secured to each other so that during operation the outer member can pivot out of alignment about a vertical axis in a direction opposite to the direction of motion, against the force of a biasing spring urging that member back to aligned position. A spray head is rotatably secured to the front end of the outer member, to rotate about a vertical axis at the center of the head. The head has a plurality of arms with spray nozzles at their ends, radially and outwardly extending from its center. Adjacent arms form angles of 90.degree. or more with respect to each other and receive between them a portion of the immoveable object.