STUDY OFANEW MODEL OF SPRAYER FOR APPLICATIONS IN “TENDONE†VINEYARDS

The present paper reports the results of some spray application tests carried out in tendone vineyards to assess the performance of a new model of sprayer whose spray boom, made of seven adjustable spraying modules, partially meets the geometry of the vegetation. Two configurations were taken into consideration: spray boom closed (T2), to improve the in field manoeuvrability, and spray boom open (T3), to approach the target with the spray modules. The experimentation was carried out within a period of two years, comparing the two prototype configurations with a conventional sprayer (T1, first year) and the effects of airflow rate and forward speed of only the prototype T3 (after we have changed the fan) on the foliar deposition (second year). An experimental design with one (the sprayers setup, first year) or two (airflow rate and forward speed, both with two levels, second year) factors was adopted, arranged according to a randomised block design with three replicates. To take into account the development of the vegetation, the experimental plan was replicated in two phenological stages: “Berries pea sized†and “Berry touch†(first year), and “Berries pea sized†and “Beginning of ripening†(second year). The first year results showed no statistically significant differences in the mean foliar deposition among the three sprayer setup, but a better uniformity with the farm sprayer in the first stage, perhaps thanks to the higher airflow rate and volume rate delivered. In the second stage, the prototype in configuration T2 was better than in configuration T3, both as uniformity and mean deposition. The second year results showed no effect of both airflow rate and forward speed on the mean foliar deposition, so the higher value achieved in the second stage with respect the first year was mainly due to the lower LAI.