MECHANICAL PRUNING OF ADULT OLIVE TREES AND INFLUENCE ON YIELD AND ON EFFICIENCY OF MECHANICAL HARVESTING

Mechanical pruning was applied using a bar with four rotating toothed disks, each 50 cm in diameter, on adult olive trees trained on vase shape. 20-year-old trees of ‘Frantoio’, ‘Leccino’ and ‘Moraiolo’ cultivars were planted at 5×5 m and the olive orchard was located in Umbria region in Central Italy. The pruning methods were: hand pruning with traditional mechanical tools; wholly mechanically pruning by topping to control the tree height; mechanical topping completed by removing the internal suckers with traditional mechanical tools; mechanical topping plus bilateral hedging supplemented by sucker removal with traditional mechanical tools. The work efficiency and the tiredness of the different pruning operations were determined and, in the years after pruning, the yield and the adaptability of the pruned olive trees to mechanical harvesting by trunk shaker with interceptor were evaluated. The results showed that mechanical pruning allows a considerable reduction in manpower. The highest reduction of canopy volume, over 60%, was observed in topping plus hedging completed with hand pruning. The mechanical pruning did not affect the yield and the mechanical harvest percentage, achieving good yield efficiency and getting crown volume fit to trunk shaker.