Analysis of the effects of ten years of mechanical pruning on the yield and certain morphological indexes in an olive orchard

The pruning of olive tree is essential to balance the allocation of energies between vegetative growth and fruiting and, therefore, to contain alternate bearing. Due to the large labour demand, up to one fourth of prime total cost is required for the pruning practice in traditional management. The high cost of labour and its scarce availability require that efficiency of the pruning practice is increased by the use of machines. This experiment compared the effects of ten years of two pruning systems, one being executed manually and in alternate years, the other adopting a three-year cycle consisting of (i) mechanical pruning in the first year, (ii) no pruning in the second and, (iii) manual pruning in the third. The yield and some morphological characteristics of plants (width of the trunk and size of the canopy) were examined in an olive orchard in Tuoro sul Trasimeno (Perugia). Plants pruned within the three-year scheme grew more promptly, achieved a significant production earlier than the ones manually pruned, and maintained an equilibrated crown. Our measurements indicated a higher cumulate production in mechanically pruned trees. The saving in labour - together with the positive effects on the production makes the three-year cycle combining mechanical and manual pruning a cost-effective option for the management of future olive orchards.