Contributed by Variedades de Olivo
Like other plants, the olive tree is governed by a development cycle bound to the seasons of the year. Thus, having spent the winter in a deep state of lethargy, it is in the spring, summer and autumn that it undergoes the most stages. Each and every one of which will depend on how the buds have evolved.
While some of the buds sprouting from the olive tree will end up turning into blossoms that subsequently give shape to the fruit, others will move towards the future becoming, first shoots and then branches. These branches, in turn, will generate new buds in such a way that this cycle is always guaranteed.
This and other subsequent cycles are known throughout the agronomous world as phenological stages and, as we have seen, the former corresponds to budding.
In this process, the origin of everything is concentrated in the buds which, in reality, protect a latent reduced version of what will be the upper parts of the tree in the future.
In the case of the olive tree, these buds are located in the leaf axil, although they may also be found hidden in the oldest wood. From the moment they start to show their first signs of activity, they may evolve in two different directions. Thus, some end up blossoming into a cluster of flowers while others give life to a new shoot with leaves. Bearing this difference in mind, we say there are flower buds and vegetative buds.
The visual differences between the two are barely discernible when closed, and they do not become clear when observing their location on the tree either, as both types choose a secluded place to grow, exactly where the leaf joins its twig.
The future of these buds will depend on the various biochemical mechanisms that take place just before the arrival of winter, which we will analyse in more depth in future editions.
The budding begins
In both cases, the arrival of spring brings a gradual increase in the temperatures, as well as more daylight hours. This triggers the beginning of the budding process in the tree. A return to life, now that the winter has been surpassed.
Logically, in the warmer regions, this phenomenon takes place earlier than in the cold zones. In Spain, this climate difference may be of up to two months, with the first olive groves budding in early March and the latest in late April.
When this process begins, the buds open the new leaves as these stretch over the outer edge, thus giving rise to the growth of a new branch. It should be clear in this explanation that the trees grow from their shoots and not, as people popularly believe, by “stretching” their branches or their trunk.
This growth will be faster or slower depending on conditions such as the availability of water and light, as well as the nutritional and sanitary conditions. This is why it is vitally important for the growth to be sufficient, as on these new branches other leaves will develop and other new buds, which will allow the olive tree to blossom the following year and which will, therefore, provide a fruitful future harvest.
In this phase, the growth pattern of the buds is always the same: two leaves that emerge in opposite directions on each internode, rotating their 90º angle on the following internode.
Chromatic variety as an indicator of change
On the other hand, we have all seen that the olive trees do not cast off their leaves in the winter. On the contrary, these gradually and naturally fall when they turn yellow on reaching the age of two or three years old. This phenomenon is more easily seen in the springtime, just when enough new leaves have appeared.
Budding changes the appearance of these trees due to the sap that is pushed onto their leaves by the roots. This is a clear sign of life that darkens or lightens the leaves as a prelude to its next stage: blossoming.
Olivarama articles also appear in Olivarama magazine and are not edited by Olive Oil Times.