A backpack spreader capable of spreading particulate matter in wide and pinpoint spray patterns. The spreader consists of a hopper having an outlet port, the hopper for holding chemical materials therein, and including a mechanism for agitating chemical materials therein, so as to keep chemical materials from sticking together. The agitation mechanism includes a main double ratchet assembly mounted within said hopper adjacent the outlet port. A hollow barrel is connected to the outlet port, the hollow barrel including aperture vanes. A manually-operated ring is externally mounted to the hollow barrel for adjusting the aperture vanes. The hopper is mountable on a back of a person. A flexible feed tube has a first end connected to the outlet port of the hopper. A dispensing gun is connected to a second end of the flexible feed tube, and is held and operated by a hand of the person. The dispensing gun held and operated by a hand of the person spreads the chemical materials over large areas or more narrow or pinpointed areas.
