A recycling tunnel to reduce environmental drift in spraying goblet vineyards

Since about 50 years ago, goblet vineyards were progressively abandoned in favour of espaliers, because they presented some critical points as low vine quality and noadequate mechanisation. Nowadays, experts and oenologists claim that goblet vineyards, cultivated with modern criteria, may provide high crop quality. Moreover, some growers are goingto set up cultivation with increased distance between rows (about 1.8 ‒ 2.0 m), that allows the use of conventional tractors designed for espalier vineyards. In order to fulfil the mechanisation requirements of the crop, the Section of Mechanics and Mechanisation of the DiGeSA of the University of Catania is developing and optimising an innovative multi-functional straddling frame, pulled from a conventional tractor, which is able to carry several tools, as vine-trimmer, sprayer, rotary hoes for soil cultivation, horizontal booms for herbicide treatment under canopies, easily available on the market. This paper reports the results of some trials carried out with the frame equipped with a tunnel sprayer, able to reduce the environmental drift during pesticide treatments. The first results showed that the recovery at fixed point, at varying pressure, distance between shields and number of open nozzles, ranged from 4% up to 83%, with general mean of 44%, whereas that during in field tests, with vineyard Leaf Area Index of 0.73 m^2/m^2, ranged from 37% up to 53%, with general mean of 46%.