Abstract: A vehicle mounted spray system includes a variable orifice spray nozzle and control apparatus to correlate the delivery of pressurized fluid spray product to the nozzle in a selected ratio to the ground speed of the vehicle. The spray nozzle includes a circular orifice with a conical valve seat and a fluid pressure responsive, spring biased, conical shaped needle valve element mounted for reciprocation therein. The taper of the valve element is less than the taper of the valve seat and the apex of the needle valve protrudes beyond the orifice to create a solid stream flow of the spray product. The solid stream spray is projected onto the surface traveled in a direction opposite the direction of travel and at an angle therewith. The nozzle velocity of the spray product is equal to or greater than the vehicle velocity.