Abstract: Sprayer boom beam structure includes a girder member having an elongated profiled sheet structure including at least two folds or bends defining three portions in an inverted V- or U- or C-shaped cross-section, i.e. a pair of side or wing walls integrally joined by a top or bridge wall. Triangular orifices are punched out of the side walls, alongside one another in a longitudinal direction, alternating between inverted and upright triangles, leaving inclined strips of sheet material in between, and which absorb and transmit strains and stresses similar to a tubular lattice structure, and having benefits of a spatial lattice-like structure. Complementary beam members include a base plate joining longitudinal edges of sidewalls of the profiled member and close the open face of the profiled member, forming a sturdy box-like structure, and internal cross-platelets joined to inclined strips of the profiled-member sidewalls to further rigidify the beam structure.