An agricultural applicator machine has a frame and at least one horizontally extending boom assembly. The boom assembly pivots to a folded position in which it is secured in a boom-cradle mechanism. The boom-cradle mechanism includes a crossmember and a boom rest at an outer end of the crossmember, the boom rest having a rigid inboard boom stop, a rigid outboard boom stop, and a saddle portion. The inboard boom stop extends from the saddle portion in an out-of-phase configuration relative the outboard boom stop. The boom-cradle mechanism has a locking assembly having an actuator assembly configured to rotate the crossmember, and thus the cradle boom rest. The actuator assembly connects to the crossmember through a linkage assembly. The actuator assembly causes the crossmember to rotate causing the boom rest to move between an open position and a locked position.