Influence of working pressure and spray nozzle on the distribution of spray liquid in manual backpack sprayers

ABSTRACT Manual backpack sprayers are widely used in rural properties in Brazil. However, studies that assess their working characteristics, especially spray tip models and working pressure conditions, are scarce. Thus, the aim of this study was to assess how much the working pressure and spray tips influence the distribution quality of phytosanitary spray solutions in manual backpack sprayers. Four spray nozzles (standard flat-fan Magnojet TP11002, turbo flat-fan TeeJet TT11002, hollow-cone TeeJet TXA8002, and disc-core) were assessed in a patternator table at 1, 2, 3, and 4 bar. Analyses of spray distribution profile were performed by symmetry and the coefficient of variation (CV) analysed by the Tukey’s test (p摘要：手动背负式喷雾器（manual backpack sprayers）在巴西农村地区被广泛应用。然而，针对其作业特性——尤其是喷雾喷头（spray tip）型号与作业压力条件——的相关研究却较为匮乏。为此，本研究旨在探究作业压力与喷雾喷头对手动背负式喷雾器的植保喷雾液（phytosanitary spray solutions）分布质量的影响程度。本研究在喷雾分布测定台（patternator table）上，以1、2、3、4巴（bar）的压力条件，对4种喷雾喷头展开测试：标准扇形Magnojet TP11002、涡轮扇形TeeJet TT11002、空心锥TeeJet TXA8002以及碟芯式喷头。通过对称性分析喷雾分布轮廓，并采用图基检验（Tukey’s test）对变异系数（coefficient of variation, CV）进行统计分析（p