The apparatus has a lifting device comprising a lifting part (4) with a cross frame (7). Left and right supports (20, 21) are pivotable around two longitudinal axes transverse to a working direction, and comprise joints, which are connected to each other over a guide rod (22) to form a four-joint chain (40). A left pivotal frame (5) with a left spray boom unit is arranged at the left support, and a right pivotal frame (6) with a right spray boom unit is arranged at the right support. A connecting rod (34) is connected with the joints for forming another four-joint chain (41).
