Olive tree response to the severity of pruning

Abstract

Pruning has been seen as a means of improving olive tree productivity. The presumed importance of pruning was describedby Columella (born 4 AD), and has persisted in general terms to the present. In this work, the effect of different pruning regimes wasassessed from two field trials conducted in Mirandela, NE Portugal, in an olive grove of cv. ‘Cobrançosa’, rainfed managed. The firsttrial began after a light crop (“off ” year) and received four pruning regimes (hard, moderate, light, and nonpruned control). The secondtrial started the following year, after a heavy crop (“on” year), and received two pruning regimes (hard and nonpruning). The studywas carried out from 2012 to 2016. The accumulated crops of the four harvests performed after pruning in the first experiment didnot significantly vary among nonpruning (8754 kg $ha^{-1}$), slight pruning (8850 kg $ha^{-1}$), and moderate pruning (8334 kg $ha^{-1}$) but wassignificantly lower in hard pruning (6449 kg $ha^{-1}$). The olive trees showed a high plasticity or tolerance to pruning, since olive yield didnot decrease in response to light or moderate pruning regimes. It seems that it is possible to carry out light to moderate pruning toachieve several objectives of orchard management without significant loss of production. The results also showed that if pruning is doneunder a hard regime it should only be performed after a heavy crop. In addition, if done under a light regime, pruning can also reducethe alternate-year bearing behavior of the olive tree.