Production Practices and Quality Assessment of Food Crops. Vol. 1

– frequency and
– amplitude of vibration, and
– travel speed.
In these harvesters, the shaking (detachment) unit is mounted on a hanging frame,
that engages the trellised vines loosely. In the lower part of this frame, a series of
overlapping plates form a catching platform. As the harvester moves forward, the
retractable plates embrace the trunks, closing the catching surface tightly. The system
has been developed to a very efficient level, where no more than a 5% of the crop
is lost for most of the grape varieties. The machine incorporates one or two lateral
conveying bands, and a loading elevator to load the grapes into the hopper, after one
or two steps of air cleaning, which eliminates leaves, dust and shoot pieces. The
harvesters work over-the-row and some are provided with sensing elements in
front, to align it to the vine rows. Present harvesters are able to work in vineyards
with narrow row spacing (down to 2 m) and are able to engage vines as low as 15–20
cm from the ground (Gil Sierra, 1990).
3.3. Tree structures
Fruit and Vegetables Harvesting Systems 273
Figure 10. Oscillatory shaker with arched rods.
Such as fruits, nuts. . . . We differentiate between open-trained trees and high-density
orchards: