In a mobile fluid sprayer system, sprayer booms are connected to a vehicle by joint structure which permits the boom to pivot upwardly and rearwardly upon engagement with obstructions. The sprayer booms are normally positioned in laterally extending orientations relative to the vehicle by cables which extend angularly upwardly from the booms and are connected to brackets which are pivotally supported on the vehicle. The brackets are spring biased upwardly, and fluid cylinders are employed to damp pivotal movement of the brackets. In this manner the sprayer booms are allowed to pivot freely upwardly upon engagement with obstructions but the return movement of the sprayer booms to the normal positions is substantially damped. Likewise, the sprayer booms are allowed to pivot freely rearwardly upon engagement with obstructions but the return movement of the sprayer booms is substantially damped by means of fluid cylinders which are operatively connected to the booms during their return movement. The damping rate is graduated in both the vertical plane and the horizontal plane such that the rate is greatest when the sprayer booms are at or near the normal positions and is substantially reduced when the sprayer booms are pivoted out of the normal positions.