Development of a sprayer PPP application in kiwi orchards “Pergola” trained

Large scale kiwi cultivation was introduced in Italy only after 1980 but it came quickly widespread all over the country and Italy actually provides the worldwide largest kiwi production. Spray application are carried out not only to prevent diseases on this plant but also to apply hormonal products and foliar nutrients: in all cases an even spray distribution on the target is required. As kiwi is typically trained at “pergola” system featured by a width of 3 m and a reduced height of plants (1.5-1.8 m) pesticide pplication are usually made by spraying only the external part of the canopy with air-assisted sprayers passing between plant rows. Due to the vegetation thickness, however, spray penetration within the canopy results generally poor. With the aim to improve the quality of spray distribution in the whole canopy, a new air-assisted sprayer prototype was developed. This new sprayer consisted of a 1000 l tank, a radial fan, and adjustable air spouts, each provided with an hydraulic hollow cone nozzle. The disposal of the air spouts was conveniently adapted in order to spray either the external or the internal part of kiwi canopy at the same time. Experiments carried out in the field showed that the use of the new sprayer prototype, enabling to spray also under the canopy vault, allowed to increase consistently the average amount of spray deposits on the leaves (up to +270 %) in the whole plant canopy with respect to the conventional application system.