A boom assembly includes a central support, a first wing pivotably coupled to the central support so as to rotate about a first axis, a first cylinder-piston assembly having a first end pivotably coupled to the support, a second end pivotably coupled to the first wing at a first pivot point for rotation about a second axis on a first side of the first axis, and a second cylinder-piston assembly having a first end pivotably coupled to the support and a second end pivotably coupled to the first wing at a second pivot point for rotation about a third axis on a second side of the first axis. Extension and retraction of the first and second cylinder-piston assembly applies varying opposing torque to the first wing depending upon an angular orientation of the first wing about the first axis. In one exemplary embodiment, the first piston-cylinder assembly includes a cylinder coupled to one of the support in the first wing having a first chamber proximate the first wing and a second chamber distant the first wing, a piston disposed in the cylinder separating the first and second chambers and a rod coupled to the piston and the other of the support in the first wing. The boom assembly additionally includes a source of fluid and a fluid line in communication between the first chamber and the source of fluid. The fluid line is configured to restrict fluid flow to a maximum first rate from the first chamber to the fluid source as a volume of the first chamber is reduced. The boom assembly preferably includes a one-way valve in the fluid line preventing fluid flow from the source of fluid to the first chamber at a second maximum rate greater than the first maximum rate. In another exemplary embodiment, the boom assembly is provided as part of sprayer, wherein the first wing carries a plurality of spray nozzles fluidly connected to a fluid reservoir.