Influence of Air-Jet Configuration on Spray Deposit and Drift in a Blackcurrant Plantation

The subject of the research was a prototype two-row sprayer, equipped with a centrifugal fan and directed air-jet emission system, dedicated to the chemical protection of berry plantations, and, in particular, blackcurrants. The prototype was set up with two configurations: “offset”, in which the opposing air streams were “offset” by 0.5 m, and “face-to-face”, when they were positioned opposite each other. The field experiments were carried out on a blackcurrant plantation (Tisel cv.; bush spacing of 4.0 × 0.5 m; height 1.2 m; width 2.5 m). The spray deposition within the crop canopies as well as spray drift to the air and to the ground were assessed using the fluorescence method in order to compare the quality of treatments performed with the two-row sprayer and a conventional axial fan sprayer with radial air discharge system. Spray applications were performed at spray volume 300 L∙ha−1 and working speed 6 km h−1 by both sprayers. The plantation was sprayed with 0.25% water solution of a fluorescent tracer BF7G. The in-canopy spray deposit and spray drift were evaluated using artificial targets made of filter paper. Although directed air-jet sprayer in two configurations (“offset” and “face-to-face”) and conventional one produced similar deposits within the bushes, the spray loss from the directed air-jet sprayer was considerably lower (25.1–32.2%) than that from the conventional sprayer (76.9–81.8%) generating considerably greater airflow volume. Lower PPP losses mean lower environmental impact, which is in line with integrated plant protection. The research responds to numerous inquiries from sprayer manufacturers and blackcurrant growers regarding the most appropriate configuration of the air flow outlet planes. The results obtained will contribute to increasing the efficiency of spraying and facilitate the implementation of the European Green Deal and the achievement of the target of a 50% reduction in the use of plant protection products after 2030 in the EU.