“Strategy to ensure productivity”
Cold accumulation continues to be and will continue to be an extremely important factor in the culmination of the recess process and the beginning of the new growth stage. However, once the development, budding and flowering processes have begun, other agroclimatic variables will be responsible for directing leaf development, flowering and fruit set, key stages in the productivity and success of the season.
How to optimize fruit set in an uncertain climate?
Considering that the period of winter cold accumulation has ended, the period between the end of the recess and the beginning of flowering-budding begins, a stage in which the temperature and the physiological processes of this phenological stage will begin to interact. What happens during flowering? During this moment, the race begins to synchronize the availability of pollen and the viability of the ovary, so that the fertilization process can occur. What and how does it happen? When the pollen grain falls directly on the stigma of the flower, a process of development and rapid growth of the pollen begins through the different floral structures until it reaches the ovary (Figure 1), a process that is led by the activity of auxins and elements that play a role as cofactor or precursors of said phytohormone (Boron, zinc). However, effective fruit set is not entirely determined by the rapid development of the pollen tube, since the viability period of the female tissue will also define whether fruit set is effective or not. How to achieve a prolonged period of egg viability? The useful or viable life of an ovule is defined for each species, however, the speed at which it will pass will be faster or slower depending on the environmental conditions that promote rapid ethylene synthesis, generating accelerated senescence of the tissue and decreasing the effective period of pollination, and therefore, a decrease in productivity (Figure 2).
What is our strategy?
If we consider that the winter period has already been covered, our proposal for flowering and fruit set is the mixture of a product that promotes the development of the pollen tube and a natural promoter of the development of auxins in the plant (Flower Power®), and a product that blocks the synthesis of ethylene, maintains the viability of the ovule for longer and stops the abortion of flowers/fruits (Bio-Hold®). Both products have been designed considering a mixture of key nutrients in the processes of fruit set and ethylene inhibition (Zinc, Boron, Copper, Molybdenum and Cobalt), in addition to hormonal cofactors, which complement what the plant is not able to produce due to environmental conditions.
In relation to fruit set and retention, the combination of Flower Power® and Bio-Hold® products is a strategy that has been used for more than four seasons with excellent results in various areas and species (cherry, walnut, almond, etc.) at a national level, as well as internationally. At a productive level and in the trials we have seen that the mixture improves fruit set and increases fruit retention compared to synthetic auxins and other synthetic molecules that inhibit ethylene (Figures 3 and 4), and the cost/benefit ratio is very positive for the producer. The success of our strategy is the combination of an auxin promoter and an ethylene inhibitor, a physiologically natural “tandem” that ensures a productive result.
Figure 1. Pollen tube growth in flower.
Figure 2. Flowering and fertilization period in fruit trees.
Figure 3. Fruit set and retention in cherry cv. Bing, O'Higgins region.
Control: Synthetic auxin 2.4 DP.
Figure 4. Retention in Nogal cv. Chandler, O'Higgins region.
