Abstract: A sprayer boom assembly comprises an elongate spray boom having outwardly foldable wing sections with a center portion pivotally mounted to an upstanding support frame of a transport vehicle for vertical swinging movement as the vehicle traverses uneven terrain. A biasing frame is pivotally mounted to the vehicle frame and the spray boom center section and connected to the spray boom through shock absorbers to dampen shocks and oscillatory movement of the spray boom. The biasing frame is tiltable about the pivot so that the spray boom can be selectively tilted to one side or another while retaining shock absorbing capability in any position. The wing sections include outer and inner wing sections of which the outer wing is automatically foldable against the inner wing through a translational to rotational movement arrangement which is actuated upon folding of the inner wing relative to the center section.