PM—Power and Machinery: Assessment of Recycling Tunnel Sprayers in Mediterranean Vineyards and Apple Orchards

The use of air-assisted recycling tunnel sprayers in Mediterranean fruit orchards and vineyards was assessed by comparing the performance of two tunnel sprayer prototypes with an air-assisted axial flow sprayer. Field trials comprised measurements of spray deposit on the canopy, off-target spray losses and the biological efficacy of chemical applications. According to the results, no spray drift was measured during the applications with tunnel sprayers. Spray losses on the ground were localized mainly under the crop rows. However, the uniformity of the spray deposition on the canopy was worse than that obtained with the axial flow sprayer. It seems that this can be attributed to poor adjustment of the tunnel dimensions in relation to the crop size or to inadequate air-jet design. Tunnel sprayers may be an option to meet future environmental requirements for spray applications, so long as crop training systems change to smaller-size orchards and wall-shaped trellis vineyards.