Bud analysis is widely known for the information it provides based on the number of buds and the number of damaged and healthy floral primordia per bud, the latter being the most important, since 90% of damaged primordia occur at the beginning of entering into dormancy, where this damage is mainly associated with poor lignification of the floral centers and/or poor bract formation.
Why does this damage occur? Mainly due to the cold during the lignification process and covering of bracts in their floral structures.
For this reason, as the seasons go by, bud analysis has taken on greater importance as a key tool in making advanced technical decisions, seeking to reduce uncertainty regarding the flowering potential of each orchard, which is one of the factors to define a correct productive equation.
It is also a tool where you can build the history of the orchard for each season, producing an important database that can be analyzed and thus project measures that are in line with understanding the floral offer for each situation.
KG/Ha = (No. Primordium/Fruit Center) x (No. Fruit Centers) x (% fruit set) x (Weight of fruits) x (Plants/Ha)
In a scenario of low flowering potential, that is, less than 15 flowers per fruit center (FC), it must be approached conservatively, where the first stage in load regulation is pruning, and where precautions must also be taken, to ensure the viability of the flowers or their subsequent fruit set, achieving fruit retention through the use of a growth regulator.
In the case of having high and excessive ranges, we must worry about a good accumulation of chilling hours and a spring with favorable temperatures and conditions for pollination and fertilization, which could translate into an eventual high fruit set, so it may be necessary to define a joint pruning strategy, early bud thinning and/or fruit thinning -for the latter, ending 30 days after full flower-.
Without a doubt, in calculating the productive potential of an orchard – in addition to the considerations described regarding the number of healthy flowers per fruit center – it is also associated with the fruit set percentage of each variety. When evaluating this factor, different figures can be obtained, in addition to adding the variety/rootstock combination, climatic zones, phytosanitary condition and homogeneity of the orchard, among others that must be taken into account for correct management if it is based on these numbers.
This load analysis becomes more important if you think that, according to the productive evidence of the last years of production in Chile, considering the kilos per hectare produced in orchards of 4 years and more at the national level as an average (internal data not available). published), it is indicated that there is a production pattern that has been marked, where you can visualize a year of high production and the subsequent 2 years of lower productivity, always being the year that follows the year of high production the most lower compared to the following year.
Understanding this pattern, pruning work with the objective of load regulator becomes very important, since it can generate a significant impact in terms of the quality and condition of the product, as well as cost control with regard to the work that could be seen later to obtain maximum crop production.
Although it could be about training, renewal and maintenance of the conduction system, we will focus on production, taking it as the most effective and economical tool to early adjust the potential fruit load. This is the most effective method for load regulation, since the intensity of the load can be decided based on the number of fruit centers per hectare or fruit centers per plant.
According to what was mentioned above, and to the extent that the fertility analyzes of buds in cherry trees this season indicate that it may be a year with a high load, this work is positioned as the most attractive for the industry. Depending on the reproductive material in each orchard (darts and twigs), the intensity of pruning can lead to a stronger pruning strategy.
In this scenario, precautions must be taken to obtain an adequate vigor/productivity relationship, in the sense that there could be greater vegetative expression with this type of “strong” pruning, and excessive shoot growth could be observed, which would alter the condition of the fruit in terms of its condition and quality, given the sink effect of this structure.
It involves the elimination of flower buds, with the aim of reducing the fruit load early in the season, this in order to improve the caliber of the fruit, although it is also the best strategy to ensure the vegetative balance of the plant and even the safest model to recover stressed plants and in a vicious circle of permanent weakness.
This strategy, although expensive, is considered the first filter for pruning load regulation. Even so, it is a task that must be carried out when the productive potential is very high with respect to the condition of each orchard, where important benefits are obtained in terms of the condition and quality of the fruit, with size being the most important attribute for the industry.
Although in other species the elimination or extinction of fruit centers is a common and successful practice for load regulation, in cherry trees it becomes an error when defining thinning or load regulation strategies if it is not accompanied by an analysis on the ground that shows us the real need.
This is because we are talking about the fruit structure that is renewable year after year, since it contains at least, and commonly, one vegetative bud, which is responsible for generating leaves and in its axles for housing new floral buds for all the coming seasons. It is for this reason that the removal of these branches is an irreversible loss in a fruit point.
Only under the analysis of the behavior of these branches in the cherry tree is it justified to carry out this extinction work, when it is desired to eliminate a section of the ring at the turn of the year, in exchange for making a cut or recess in this area, or also in special situations where 2 or more branches are found in a single fruit center, generally found in orchards with high flowering potential, weak rootstocks and high set varieties.
Research carried out in Chile in the past has shown that these load regulation strategies are successful.
It should be taken into consideration that this tool should be used with caution, depending mainly on the rootstock/variety combination, since excessive flowering potential – according to the infographic for self-incompatible varieties such as Regina and Kordia – does not have the same interpretation. in practice to regulate the load with strong pruning or thinning, however when compared with a self-fertile variety such as Lapins, it is necessary to prune strongly and thin the buds.
An early load adjustment – whether with pruning and/or thinning – depending on the determined need, will be the best tools to achieve the objective of reaching a fruit caliber curve, where the sum from 28 mm upwards is at least 70%.
It is known that the greater the distance between the load adjustment at full bloom, the greater its impact on the size and soluble solids, which can be observed at harvest, with the size being the most commercially important, as has been observed in the last export seasons.
The use of load regulation techniques is mainly given by the background information provided by the AdYC for each variety/rootstock combination, vegetative state, health condition, among other factors, where not carrying out this action is much more costly when the orchard needs it.
Originally published in Spanish at Smartcherry.cl