If the trees are old, exhausted or neglected, then pruning should be severe. This type of pruning will strengthen the germination and restore the balance between the roots and the above ground section. In this case, the limiting factors are not carbohydrates but minerals. The amount of minerals, especially nitrogen (N), directed to the smaller crown increases, thus enhancing the germination of the trees.
When the olive grove shows low vigour, poor production, many dead shoots and yellowing leaves, the trees must be pruned for renewal.
All or part of the crown is removed at branch height, three months before flowering. The main branches are cut at a distance of one metre from the trunk. Renewal is best done gradually, i.e. 2-3 branches are removed in the first year and the rest in subsequent years. New shoots will appear and fruiting will resume in four years. Crown renewal should be done every 10-20 years. Large incisions should be covered with grafting ointment.
In addition, with renewal pruning the following is carried out:
- The dry branches are removed.
- Cut the orthobranch or side-branch secondary branches to 50% of their length, with the cuts made on a side shoot.
- The supernumerary branches are completely removed.
Severe pruning favours the establishment of new vegetation, which must be thinned by pruning. For the next two years, no nitrogen fertilisation is applied to reduce the vigour of the tree and prevent the development of offshoots.
Bibliography
THERIOS, J. N. (2005). OLIVE GROWING.https://www.malliaris.gr/ΕΛΑΙΟΚΟΜΙΑ-(ΘΕΡΙΟΣ)-960-88706-0-7
