The increased pressure to improve fruit quality, reduce losses due to disease and deal with the shortage and expense of labour has led to the increased use of machinery to strip leaves in the grape zone.
The Alsatian company Provitis offer two types of stripper, the suction roller type LR 350 but also the pneumatic type LB 260. The latter uses rotating jets of air at 0.6 to 1.0 bar to shred the leaves. A blower generates the air pressure passing it to the rotating nozzles which strip the leaves. The working height in the grape zone can be adjusted from 400mm to 640mm by tilting the heads. With the leaves gone, better airflow through the canopy contributes to drying and therefore less disease incidence; spraying is more effective as fungicides can be applied directly onto the berries.
When used early in the season it helps blow the caps off the emerging flowers and when used the day before or on the day of harvest greatly reduces hand picking time. Different models are available to work on half a row (single head), two half rows (two heads left and right) or a complete over row with two heads. The compressor blower is always at the rear of the tractor but the heads can be at the front and if a Provitis mast is already used for trimming or pre pruning a stripper head can be added.
