Trials on the Convenience of Mechanical Pruning of ‘Tonda Gentile delle Langhe’ in Piedmont

To obtain robust and extensible experimental results on the agronomic\r\nconvenience of mechanical pruning of old bush trained hazelnut orchards in\r\nPiedmont, during the period 2006-2010 four trials to compare mechanical, manual\r\nand no pruning trees were made in 4 representative locations (=orchards). The\r\norchards, located on flat or sloping grounds and growing TGL trees 6 to 18 years\r\nold, were pruned in March or in September, obtaining for each location 6 plots of\r\n10-15 trees replicated twice and pruned once during the period 2006-2008.\r\nObservations generally regarded: pruning duration (s/tree) and amount of pruned\r\nwood; yielding and nut quality for at least 3 years after pruning operations. The\r\nresults of the four trials were the following:\r\n- mechanical pruning duration was 1.4-3.9% higher than that of manual pruning.\r\nThese figures can increase to 8-10% if device position time, manual finishing of\r\nlarger cuts and desuckering are also considered;\r\n- the cumulative yield, 4 years after pruning operations, is equal but often greater\r\nfor the mechanically pruned trees compared to non-pruned or manually pruned\r\nones. These results are evidenced both in March and September trials. The\r\ncumulative production of manually pruned trees reached the amounts of the nonpruned\r\nplots only after 4-5 years. The convenience of pruning both by mechanical\r\nor manual system is evident starting from the first year after the cuts because of\r\nthe better technological traits of nuts (e.g., seed weight, commercial rate, incidence\r\nof external and internal defects). However, these results are not registered for the\r\nyounger orchard.