VINEYARD EVALUATION OF A RECYCLING TUNNEL SPRAYER

This article presents the results of field trials of an air-assisted tunnel sprayer with a recycling system for the liquid that is not retained by the leaves. Its characteristics and performance, in terms of distribution quality and losses to the soil, were compared with a conventional air-blast sprayer. The trials were done in a vineyard trained to spur-pruned cordon at two growth stages using a fully randomized experimental design. The results show that losses to the ground with the tunnel sprayer were less than 5% of the sprayed liquid in both growth stages, which are much lower than those of conventional sprayers. The amount of liquid retained by the leaves was about 87% of that distributed in both stages. Biological tests carried out during the season showed no significant difference between the sprayers in terms of efficacy. The overall results point out that the tunnel sprayer using this type of air-circulation system requires much less chemical product and shows higher environmental sustainability in comparison with conventional air-blast sprayers