Before starting to pruning cherry trees, it is important to decide the objectives to be achieved. Thus, when cherry trees in a commercial plantation are pruned, what is sought is to obtain the highest number of quality cherries possible.
The price of quality cherries more easily exceeds the break-even point of the farm.Cherry picking and care costs of the cherry tree (pruning, fertilization, phytosanitary treatments…) If we have ornamental cherry trees, the Pruning should be aimed at controlling the size and favoring the splendor of the cherry blossom tree .
When to Prune Cherry Trees?
The best time to prune the cherry tree, as well as other trees and fruit trees of deciduous leaf (almond tree, apricot tree, peach tree, plum tree…), it is during the end of winter, once the cherry tree has shed its leaves and before it begins to mobilize its reserves for spring. December and mid-February is the most common time for cherry tree pruning.
The ideal time will depend on the type of pruning to be carried out and our growing area. Personally, I start pruning from mid-January, once we finish the harvesting olives.It is necessary to avoid pruning cherry trees when severe cold or rain is forecasted, especially if phytosanitary treatments are not applied and pruning wounds affect main branches. Wet areas such as Galicia, it is recommended to delay pruning as much as possible.
Cherry tree training pruning
The cherry tree has difficulty emitting lateral shoots. For this reason, training pruning is very necessary, thanks to this pruning, it is possible for the young cherry trees to branch in the desired way.
Currently there are numerous pruning techniques adapted to different types of cherry plantation. In Spain, the use of the Spanish vase for the formation of the cherry tree in intensive plantations is still common. However, new high-density plantations require another type of training and maintenance pruning.
Spanish Bush (SB) or Spanish Cup
The formation of cherry trees in Spanish vase is quite simple and low cost. This pruning is suitable for patterns of medium or higher vigor and for both upright and open cherry trees.
It favors the formation of an open tree that does not reach excessive height, an aspect that reduces harvesting costs when the trees are small.
As a drawback, training pruning slows down the growth of the trees, so it is not possible to improve earliness. Spanish research centers have traditionally planted on SL-64 a 5×5 meter frame, using this However, other publications recommend a planting framework similar to that used in the KGB pruning system.
Kym Green Bush (KGB)
The cherry pruning system Kym Green Bush, also known for short by KGB. It is a training system initially developed in Australia by cherry grower Kym Green and improved in the United States by Lynn Long. The system consists of creating multiple vertical fruiting axes, which will be renewed regularly to keep the cherry trees young and productive.
The number of axes will depend on the vigor of the tree, vigorous trees needing to have more axes.
Its advantages include cost savings (simple pruning, cherry picking from the ground, no need for guide structures…) It is used on vigorous or semi-vigorous rootstocks and in < strong>Spur-type cherry varieties (upright growth). The main drawback of this training pruning is that it slows down the growth of the trees, so improvements in earliness are not achieved.
In semi-vigorous rootstocks, the plantation frame is 1.80 to 2.40 meters between trees and for vigorous ones between 2.40 and 3 m. On the other hand between lines of cherry trees between 4.20 and 5.50 meters is recommended. As is logical, the greater the vigor, the greater the distance between trees will be necessary. Approximately between 800 and 1,300 cherry trees per hectare.
Vertical axis or Steep Leader (SL)
Developed by growers in Washington state, this system appears to have no advantage over the KGB or the Spanish glass It consists of 3 or 4 vertical axes on which it branches and forms a pyramid-shaped tree.
This structure requires more space than the other systems and is more expensive to build, as it is necessary to anchor the branches during the formation of the tree. It admits between 400 and 800 trees per hectare.
Super Slender Ax (SSA)
Pruning technique developed by Stefano Musacchi, a researcher at the University of Bologna. The aim is to obtain early planting with very high-quality fruits. For this system, early cherry varieties must be used that bloom on the basal buds of the shoots of the year. And dwarfing rootstocks, to control the vigor of the 3,000-6,000 trees/ha.
The low production per tree is compensated by the large number of planted feet. As disadvantages, plantation is very expensive and training pruning is very laborious. In addition, advanced technical knowledge is required to achieve correct vigor control.
Central axis system or Vogel Central Leader (VCL)
Take advantage of the vertical growth of the cherry tree, reducing the number of cuts necessary for formation pruning. In this way, it is possible for the cherry tree to start producing earlier. However, this type of pruning is expensive and does not reduce collection costs.
Other training systems
In addition to the previously defined systems, there are others such as Tatura, Bandera, Tall Spindle Axe (TSA), Upright Fruiting Offshoots (UFO), Upright Fruiting Offshoots “Y” Trellis (UFO-Y), etc.
Reading the following publication on the different driving systems.
As we can see, it is possible to prune a cherry tree using different interesting techniques. In the future, I am sure that new methods will continue to emerge to perform cherry tree pruning.
Pruning cherry tree production: quality cherries
In cherry tree cultivation, obtaining quality cherries is essential to obtain profitability. Quality cherries are understood to be those for which the market is willing to pay a higher price, compared to other cherries obtained at the same time.
The main preference of consumers is centered on the size of the cherry, although firmness and flavor are essential for buyer return. The prices received by the farmer range from 0.50 to 1 euro/kg for low-calibre cherries and between 1 and 2 euros for good quality cherries.
Regarding the costs of collection and cherry selection, they are approximately 1 euro/kg. Therefore, it is more profitable to obtain an average production of good quality compared to high productions.Because of this, the pruning of cherry tree production is essential.
How to prune a cherry tree in production?
When the cherry trees come into production, the intensity of pruning to be carried out will depend on each variety of cherry.
Varieties with a tendency to overload need more aggressive pruning to reduce production and obtain acceptable sizes.
For example, during cherry blossom, an important aspect is the number of flowers per flower bud. In the case of Lapins it is very high, with between 3 and 5 flowers per bud. Varieties such as Sunburst have 2-4 flowers and in other varieties only 1-3 flowers can be seen per bud. Just as important is the number of buds on each May cluster and the number of May clusters per branch. Using the three data, we can obtain the existing flower density.
Once the flowering density of cherry trees is known, it is important to know whether they are self-fertile or self-sterile cherry varieties. greater number of fruits during pollination and are usually more prone to overload.
The vigor of the tree: taking into account the state of the cherry trees is important, weakened cherry trees have a greater risk of overloading. In this case, it will be necessary to eliminate a greater number of flower buds and carry out actions (subscribers, control of cherry tree pests and diseases…) to increase vigour.
On the other hand, it is important to reduce excess vigor of the cherry trees, since the resources of the cherry tree are mobilized to grow instead of producing. In these cases, you can opt for techniques such as green pruning or the application of authorized products to regulate growth ( CULTAR ®).
Assessing cherry tree pruning needs
According to the density of flowers, pollination needs and vigor, we can establish pruning criteria. It is important that the farmer adapts these criteria to the conditions of his cherry orchard.
Simplified analysis of cherry tree pruning needs
To assess pruning needs in a simplified way, we have taken into account the following factors:
- Cherry vigor: The greater the vigor, the less floral induction and greater load capacity. Therefore, pruning needs in vigorous cherry trees is lower.
- Density of flowers: the greater density of flowers favors the number of fruit set. Due to this, the higher the density of flowers, the greater the need for pruning to obtain quality cherries.
- Self-fertile: Self-fertile varieties tend to set more easily than self-sterile ones. Therefore, more pruning of self-fertile varieties is advisable.
Some examples of the type of pruning to develop
The concepts of important, medium and light pruning are indicative, the professional pruner must base himself on his knowledge. Carrying out an important pruning does not mean leaving the cherry tree without branches where it can produce. But it can mean reducing the number of fruitful formations by 30-5%, when overloading the tree is foreseeable.
- Varieties with a high density of flowers + self-fertile + low vigour: Need for significant pruning. A reduction in the fruit load is sought to improve the caliber, promote growth and strengthen the trees. In aged plantations, replanting the ground with other rootstocks and new cherry varieties, may be more interesting.
- Varieties with high flower density + self-fertile + medium vigour. Medium intensity pruning, light load reduction and better lighting of the branches to increase calibers.
- Cherry trees with high flower density + self-fertile + high vigour. Light pruning, removing suckers and favoring good lighting of the branches.
- Varieties with low flower density + self-fertile + low vigor. Medium pruning required.
- Cherry trees with low flower density + self-fertile + medium vigour. Low intensity pruning, to improve the lighting of the branches and increase the calibres.
- Varieties with low flower density + self-fertile + high vigor.
Light pruning, removing suckers and favoring good lighting of the branches.
As we have seen, in the case of self-sterile varieties, pruning must be somewhat less aggressive.
- Cherry trees with high flower density + self-sterile + low vigour: Need for medium pruning.
Green or summer pruning of cherry trees
Green pruning seeks to weaken the trees and reduce vigour. It serves as punishment pruning to control the size of the cherry trees and increase the floral induction. This type of pruning is suitable for mature cherry trees (they have reached their final size and we want them to start producing).
By cutting the vigorous shoots that compete and bore the lower branches, we help the branches of the cherry tree, instead of drying out due to lack of light, to be filled with May bouquets. You have to be careful with green pruning to prevent the sun from producing burns on the wooden structure of the cherry tree.
In young cherry trees it is used for formation pruning and can delay the entry into maximum production. However, the ramifications have more closed angles than those that sprout on winter buds.
Treatment of cherry tree pruning wounds
The cherry tree is a tree with low sprouting capacity, therefore which responds badly to aggressive pruning. When the branches of the cherry tree are pruned, it is essential to use healing paste to seal the wounds produced. Furthermore, despite the hardness of its wood, fungi break it down easily.
Therefore, it is very convenient to apply healing paste when branches are cut, especially if the main branches of the cherry tree are pruned. When healing agents are not used, the trunk dries easily and is very sensitive to the colonization of fungi and rot. There are many products to choose from, I personally like to use the Arbokol healing resin, it’s strong, easy to apply and facilitates the formation of calluses in wounds.
We have translated the information on our website from Spanish to English. Please note that some words may have had their meaning altered during translation.