Abstract: An agricultural sprayer (10) comprises a mobile frame (12) supporting a spray system (90) in which the water and chemical concentrate are stored in separate tanks (92, 94, 96 and 98) for mixture in the desired ratio as needed responsive to travel of the sprayer so as to facilitate application at the proper rate. The frame (12) preferably comprises a main frame section (14) with outboard pairs of pivotal frame sections (16, 18) which are individually supported by adjustable gauge wheels (34, 54) movable between raised and lowered positions relative to the ground by actuator assemblies (60). The spray system (90) includes a water tank (92) and a plurality of chemical tanks (94, 96 and 98) connected through individual shut-off valves, adjustable, positive displacement pumps, and an electrostatic water treater, to a plurality of spray heads.