Influence of canopy density on efficiency of trunk shaker on olive mechanical harvesting

On 10-year-old trees of Frantoio, planted at 5x5m and trained to vase, a light, moderate and heavy pruning was applied at intervals of 1, 2 and 3 years. In 1998, in conditions of high crop load and at the third year of trial, trees with the complete range of treatments were available. The tree production on annual pruning was 6.9, 11.5, and 20.83 kg for heavy, moderate and light pruning; for intervals of 2 and 3 years the yields were higher than 20 kg for light and moderate pruning, while for heavy pruning it was about 17 kg. On these conditions the trunk shaker showed a significant increase in percentage of fruit removal from light to heavy annual pruning, passing from 82.76% to 93.66%. On trees pruned at intervals of 2 and 3 years the average fruit removal was 84%, with the tendency to have better results when heavy pruning was used. Therefore the trunk shakers were effective for mechanical harvesting of medium sized trees, during an optimal harvesting period for oil quantity and quality. The moderate and heavy annual pruning helped mechanical fruit harvesting because of a larger fruit size, a less dense canopy, a regular distribution without bundling and overlapping of fruity shoots. However in trees with longer intervals of pruning good results were also obtained.