Efficiencies of a hand-held vibrator for harvesting fruit from ‘Tifblue’ (Rabbiteye blueberry) [Vaccinium ashei (Reade)] were investigated in relation to the properties of fruit and force required to dislodge fruit.
It was found that the heavier fruit dislodged quicker than the lighter fruit, it is thought that this is due to increased inertia movement associated with the heavier fruit.
The degree of force required to dislodge the fruit from the pedicel was much the same as one required to dislodge the pedicel from the peduncle in green fruit. In ripe fruit (all blue color), on the other hand, the former was far less than the latter. This indicated that the pedicel, an unwanted item in the market, was separated from ripe fruit more readily compared with green fruit.
Ripe fruit dislodged more readily at a low vibrant frequency than less ripe fruit. Ripe fruit dislodged most efficiently at a 30mm stroke and 7.5Hz frequency, although with this vibration mode almost all the green fruit did not dislodge.
On the other hand, when applying the vibration to the shoot (30mm stroke and 7.5Hz frequency), among the fruit which were dislodged there were a few fruit with pedicels attached which needed to be graded out before shipping to the market. However, there were few ripe fruit among the fruit left on the shoot, and the fruit dislodged were mostly ripe fruit.
