Fecha de publicación: 18/11/2002 Fuente: Wipo "precision farming" An assembly (10) fed by a pressurised pipe (2) and comprising three differently rated spray nozzles (11, 12, 13) is mounted on a spray boom so that 11, 12, and 13 traverse the same area. The nozzles (11, 12, 13) are independently remotely pneumatically controlled to give an overall spray rate range of from 0.4 to 2.5 litre/min., useful in precision farming.