Preliminary Results about the Influence of Pruning Time and Intensity on Vegetative Growth and Fruit Yield of a Semi-Intensive Olive Orchard

Abstract

The effect of extending the pruning time and reducing the pruning intensity was
\ninvestigated on vegetative response and production of three Italian olive cultivars
\n(‘Raggia’, ‘Maurino’ and ‘Leccino’) in central Italy. From 2009 to 2011, pruning was
\nperformed on 5-years-old olive trees in early spring (after bud break) at two intensity
\nlevels (minimal and heavy) and in late spring (after full bloom) at a heavy intensity. A
\ncontrol set of plants was left unpruned during the experiment. Results showed that the
\nabsence of pruning minimized water sprouts growth and initially generated the highest
\nyield. The productive advantage offered by not pruning decreased at the third year. After
\n3 years of no pruning, the plants showed an excessive height, shading of the central
\nportion of the canopy, and negligible vegetative growth, inducing an early senescence of
\nthe productive branches and necessitating the removal of a massive amount of dry
\nmaterial by applying a severe pruning operation (rejuvenation) at the end of the trial. The
\nearly spring minimal pruning technique led to the lowest amount of pruning material and
\nprovided a consistent increase in plant production compared to heavy pruning. Late
\nspring pruning did not provide competitive advantages in terms of vegetative re-sprouting
\ncontrol nor yield compared to early pruning. This preliminary study suggests early spring
\nminimal pruning in central Italy as the best practice to increase stability in yield and to
\ncontrol the vegetative growth of olive trees in semi-intensive orchards.