Fuente: Wipo "precision farming" A spray system is provided with improved spray control having decreased injection lag, and reducing non-uniformity in injection lag throughout the length of a spray boom. A pump is coupled to spray nozzles installed along the spray boom by manifolds which divide the spray boom into a predetermined number of zones. Each zone has a respective boom manifold, and each boom manifold is coupled through equal length line to the spray nozzles. The size of lines coupling the pump to the boom manifolds varies with position along the spray boom and restricting orifices are used in some of the connecting lines. Application systems constructed according to principles of the present invention respond quicker to changes in pump operating points than conventional systems and variability of injection lag along the length of the spray boom is virtually eliminated with the present invention.