Abstract: An agricultural boom is made up of two sections connected together, including an inner boom section and an outer boom section that are joined together with a hinge assembly in mid portions of the boom. The outer boom section is mounted to the inner boom with a linkage and control cylinder that provides for a knee action, that permits the outer boom section to be raised and lowered. The boom sections are both mounted about upright axes, and are supported against downward loads by separate pairs of cables that have ends joined at the base of the respective boom section at spaced points and connected to the outer or free ends of the respective boom sections at common points. The cables permit the boom sections to pivot about their respective upright axes with one of the cables carrying tension loads and causing the outer or free ends of the boom sections to raise while the other cable becomes slack.