Each season cherry producers work tirelessly to achieve the greatest productive potential of their orchards, with fruit of excellent quality, good color, size, good sugar levels, etc.

However, to reach that goal, agronomic management is not always the same since each year presents a different scenario. When there are enough chilling hours or very good cold quality, for example, trees naturally wake up early, which can promote early flowering.

Other points to consider are related to spring and the temperatures that occur in this season and, on the other hand, the degree days, which play a fundamental role in generating sugars through the metabolism of photosynthesis.

But what does all this have to do with pruning? Well, simply because these types of conditions are a reliable example of the different scenarios that each season can present, where climatic factors play a fundamental role. Thus, it is necessary to evaluate the agronomic management that will be carried out in the orchard and not repeat them year after year, as if it were a recipe.

Returning to the objective of every producer, pruning is presented as a fundamental task for the maintenance, renewal and optimal management of a cherry orchard; Furthermore, it is a strategy that, used correctly, allows you to achieve the productive potential of a garden; Of course, it depends on the time in which it is carried out and under what conditions.

Load regulation is essential to obtain good-sized fruit, this type of pruning being what allows unifying size and distributing sugar in the fruit. Furthermore, especially in cherry trees, this technique stands out for its efficiency and for being economical.

Why prune or regulate load?

Controlling the fruit load of the cherry tree aims to renew its reproductive structures, an important task to avoid an excess of fruit and thus a gradual weakening of the trees, which leads to a decrease in the quality of the fruit.

Now, before pruning and defining its intensity, along with the number of fruit buds that should be left on the tree, it is important to take into consideration the variety/rootstock combination, the quality of the fruit buds that the tree has, how it was the fruit load the previous season, climatic conditions and the accumulation of chill hours during the period.

Another important factor is the analysis of bud fertility, which allows to calculate  and manage the productive potential, being one of the most objective tools to know the load status of an orchard. It has become essential to incorporate techniques that enhance the size and firmness of the fruits, which is achieved mainly by regulating early loading.

There are several types of load regulation, pruning being the main one, but thinning of reproductive structures such as buds, flowers and fruits, is also a good technique; The earlier in the season it is done, the more successful it will be for quality and fruit condition. This is the second most suitable method of load regulation.

Thus, the analysis of bud fertility is a tool that allows us to better demonstrate the reproductive status of the orchard at a certain time of the season; It is a key factor in deciding on the type and intensity of load regulation techniques to be executed; The results of those analysis will also provide enough data that to reinforce what we just explained, that all seasons are different.

It’s pruning time

It never hurts to remember the concepts of pruning and load regulation. Therefore, below is a small summary with definitions, as well as the most recurring procedures in the management of the different structures.

1. Renewal pruning

The main objective of this work is to renew the “permanent” structure of the plant; That is, those branches that generate excess shade and are no longer protagonists in production, since they lack fruit centers. It should be noted that in many cases these structures are young, with excess vigor that a future productive branch will not take advantage of.

This type of material must be “removed” with a base “stub”, in order to accommodate future renovations from there and avoid the loss of primary structures of the plant.

2. Branch pruning

This work considers intervening on one-year-old wood during winter, or less than one year old if it is done green during spring/summer; Its goal is to promote vegetative development just behind the cutting section. This type of pruning allows for a “new phase” in the development of the new vegetative section, avoiding premature hardening.

Although there are those who claim that this intervention of one-year twigs promotes “hardening”, it is necessary to clarify that this concept is wrong and that it is even exactly the opposite.

3. Trim or lower branches.

It consists of intervening branches in sections of two years or more, and seeks an early load adjustment, in order to leave out excessive fruit centers. This intervention should be carried out just after a ring of the change of year or in a section that generates self-support of branches.

The concept of self-support of branches refers to the fact that the fruit containing that section of branches is supported by its structure, ensuring vegetative development and generating a more regular result in terms of balance in fruit size and composition of sugars and nutrients. 

4. Cluster bud thinning or extinction

This strategy is by far the most effective, compared to thinning flowers and fruits that have already set. Its objective is to reduce the fruit load and, in the process, ensure the vegetative balance of the plant. Furthermore, this type of thinning is the safest model to recover stressed plants in a vicious circle of permanent weakness.

To carry out this strategy, it is essential to have the results of the bud fertility analysis, as it is an objective tool that will allow defining the intensity of bud thinning. The above is also associated with the fertility of the variety, rootstock, conduction system and also the vigor or weakness of the combination.

5.Thinning or extinction of darts

In cherry trees, the extinction of darts becomes a blunder when defining thinning strategies or load regulation; Although in other fruit species this practice is common and successful, in this particular species the elimination of a bud is the irreversible loss of a fruiting point.

Because? It happens that in cherry trees the bud itself is the renewable fruit structure year after year, since it contains at least, and commonly, a vegetative bud that is responsible for generating leaves and, in its axils, housing new floral buds every season. For this reason, it must be considered that the only extinction of buds that could be justified is that of a section of the year-change ring, in order to make a cut or recess in this area.

Having reviewed the load regulation strategies, it only remains to reiterate the importance of being clear about the different panoramas that each season presents, even in the same orchard or plant; Bud fertility analyzes are essential, since with these objective results it is possible to make concrete and right decisions. It is also important to have the projected fruit set information according to the variety/rootstock combination and the historical information of each orchard, as this largely determines the different tasks that will be carried out (pruning, thinning, etc.).

On the other hand, it must be taken into account that to carry out any type of pruning or load regulation strategy, it is necessary to have an orchard in optimal conditions from a phytosanitary point of view, with its programs up to date, which will allow the success of the agronomic management described above.

Also do not forget that everything that is done in the garden must be carried out with the greatest amount of information possible and always in accordance with the productive objectives that are pursued… It is time to ask yourself today what you are looking for for the next season.

Technical article by Carlos Tapia, Founder and Director of Avium; Emilio Martínez, Avium R&D Leader. Originally published on Smartcherry.cl

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