A stabilising and release system, for an agricultural apparatus having a mounting portion for mounting the apparatus to a tractor, a pendulum mounted on the mounting portion, and a boom for spraying or cutting, which is pivotally mounted to the pendulum at a pivot point so as to allow pivoting of the boom relative to the pendulum. The system stabilises the boom against movement imparted to it by disruptive forces which disturb the natural position of the boom by proving a rigid damper arranged between the support frame and the boom and arranged to damp relative movement of the boom and the mounting frame caused by disruptive forces, the damper has an articulated coupling which allows the damper to articulate so that the damper can follow the motion of the boom thus damping any undesired swaying action caused by bumps and ruts over which the tractor passes.