Abstract: A boom for spraying equipment comprises at least one elongate member having an outer skin over a core of a material having a lower density than the skin. The core material may occupy all of the space within the outer skin or the elongate member may be hollow, at least part of a side wall of the member being formed of an outer skin, an inner skin and core material sandwiched between the inner and outer skins. The outer skin and the core material may be metallic or non-metallic, suitably a fibre reinforced plastics material. There may be a plurality of elongate members which are mutually spaced, parallel arranged and extend in a direction lengthwise of the boom.