Quantifying canopy deposition and ground losses of fixed spray delivery system layouts for trellised vineyards

A fixed spray delivery system (FSDS), a pesticide application technique based on a modified irrigation system, is raising interest among farmers for spray applications in 3D crops. This vineyard field study compared the spray performance of four hydraulic-based FSDS layouts (L1, L2, L3, and L4) combining three emitter types with different emitter densities (number of emitters per row length). Tartrazine dissolved in water (10 g L-1) was used as testing liquid. Spray deposition and ground losses were assessed by sampling vine leaves and by placing Petri dishes on the ground, respectively. Samples were analysed using spectrophotometry. The dataset analysis showed a statistically significant effect of layout on mean deposition and ground losses. In general, layouts with a higher emitter density (L2, L4) should promote depositions, but in the hydraulic-based FSDS, result in lower canopy deposits. The emitter density and layout are the key factors affecting the spray performance of a hydraulic-based FSDS.