Quality of fungicide application on trellised grapevines by a sprayer prototype

The main way of controlling grapevine pests and diseases is by spraying them with crop protection products. The aim is to deposit as many droplets as possible on potential or already established infection/infestation points. A prototype sprayer was constructed with its nozzle holder booms forming a kind of tunnel that travels over the plants. Spraying is thus performed in an enclosed space, preventing the shower of droplets from being blown away by the wind. A low evaporation rate is also achieved. Further, since the droplets have to travel only a very short distance between the nozzles and the plant surface, the coverage achieved approaches the ideal for crop protection purposes. The efficiency of the applications was determined using water-sensitive paper attached to the leaves of the plants during spraying; after spraying, these were examined using an artificial vision system. The results show that, at the maximum pressure assayed (0.6 MPa), the mean coverage percentage exceeded 54% – sometimes reaching up to 79%. This indicates that ideal product application conditions were approached, the product forming a nearly continuous film on the plant surface