Directed spraying in sugarcane. II: spacing between floodjet nozzles for herbicide application

摘要

Post emergence late herbicide application in sugarcane, shoud be carride out prefereable in inter-row, directing the spray mainly to the weeds. This study was performed aiming to evaluate the use of two Floodjet nozzles at the center of row sugarcane in situation of the most usual sugarcane row spacing in São Paulo State. It was started by the determination of spray pattern of tem FS-VS4 nozzles in a patternator with 67 channels, at six heights. An appropriated computer program simulated the spray deposition from two nozzles separated 20 to 70cm in the center of inter-row sugarcane. Results indicated: a) at the started, nozzles output was 2.3 l/min, with a coeficient of variation of 2.5%, showing good respectivity and reliability. Regarting to the spray pattern in was observed a good precision with a narrow confidence interval by channel; b) it was observed that in the best combination of the relation nozzle spacing by height was about 1.4. For example, nozzle spacings at 50 cm and nozzle height at 35cm, for sugarcane inter-row at 140cm.