Development of a fixed spray delivery system for Guyot-trained vineyards

This thesis aims to enhance the study of the hydraulic-based fixed spray delivery system (HSD-FSDS) and provide key insights into the possible use of this technology in Guyot-trained vineyards. The HSD-FSDS is a novel pesticide application technology that shows potential for adoption in crop fields where conventional sprayers are not easy to use (those characterized by steep-slopes) or where the only options are hand-held sprayers (backpack sprayers, and lances). In the presented examples, this novel pesticide application technology shows great promise in reducing labor input, potentially optimizing the quality of agrochemical distribution, and enhancing operator safety. These new technologies are composed of two main elements: i) the delivery system, and ii) the pumping station. The delivery system is composed of a permanently positioned polyethylene line and, connected to it, a series of emitters both installed within or above the canopy. The polyethylene line connects the pumping station and the emitters through which the spray mixture is delivered to the target (crop canopy). The pumping station, located outside the field, supplies the entire system with the spray ensuring that the spray mixture reaches all emitters regardless of their location from the pumping station. The work is organized into six chapters, each addressing a specific research gap through studies published in peer-reviewed journals or presented at international conferences. Chapter I focuses on the identification and laboratory characterization of various HSD-FSDS emitters, evaluating their flow rate, spray pattern, and droplet size spectra to determine their suitability for vineyard use and the components' working parameters. In Chapter II, the best-performing emitter identified in Chapter I (StripNet mod. STR31 2AN) was tested for spray coverage in apple orchards and vineyards, with comparisons made against conventional sprayers equipped with modern spray drift reduction technologies. Chapter III evaluates a prototype HSD-FSDS in terms of spray homogeneity and internal cleaning performance. Since HSD-FSDS technology is intended for the application of agrochemicals, it must ensure compliance with the EN ISO standards applicable to conventional sprayers. Chapter IV broadens the investigation to include a second type of FSDS, the pneumatic-based system (PSD-FSDS), which is optimized for vertical shoot position-trained vineyards, assessing its internal cleaning capabilities and regulatory compliance. Chapter V proposes a methodology for the functional inspection of FSDS, addressing the current lack of specific regulations in this area. This methodology aims to ensure the quality maintenance and performance of FSDS components over the years following their installation. It serves as a baseline for the mandatory functional inspection of HSD-FSDS in apple orchards within the Trentino region. Finally, Chapter VI examines spray deposition and ground losses across different HSD-FSDS layouts in vineyards, highlighting the influence of emitter density and layout on spray performance. A series of improvements, such as creating a specific emitter type with precise characteristics, were suggested based on the outcomes to enhance the spray quality performance of the HSD-FSDS. The findings from these studies offer practical recommendations for the installation and management of FSDS in vineyards, contributing to optimizing the agrochemical delivery with this novel pesticide application technology.