A field crop spray apparatus (1) comprises a carrier (5) which can be coupled to an agricultural tractor. A plurality of frames (7) are attached to the bottom of the carrier. The free ends of the frames are provided with rotation dampers (9) to which an elongated blade (11) is fitted. This blade runs parallel to the carrier (5) and sprayers (13) are present on top of the blade (11). The field crop spray apparatus (1) further comprises a cylinder (15) which is connected to the carrier (5), and also a piston (17) that is movable inside the cylinder (15) and is connected to the blade. The piston (17) can be moved with one end in a slot (19) present in the blade (11) and can also be disconnected from the blade.