ABSTRACT

A high-speed in-canopy center pivot chemigation system is being developed which utilizes variable frequency control to the tower motors to give continuous uniform movement. Valves located above LEPA irrigation nozzles are used to divert flow to a chemical application nozzle package which is sized to give 1/4 the irrigation flow rate at 2 to 4 times the irrigation pressure. High system speed and auxiliary nozzles combine to give chemical application volumes which are from 1/8 to 1/16 that of conventional chemigation systems. Chemical deposition unifomiity on plants is vastly superior with the new system as is the chemical concentration remaining on the plant. Effective postemergence weed and grass control which normally requires very low-volume application has been obtained with the system.