In the late 1990s, many avocado orchards in Chile entered winter as if they were deciduous trees. Fertilization stopped in March, and with the first rains of May and June, irrigation was also suspended. The implicit message was clear: the plant was going dormant, and there was little that could be done until spring.

But the avocado was never asleep.

The arrival of the first Israeli consultants changed that perspective forever. Experts like Moshe Besser, Michael Noi, Isaac Adato, and Udi Gafni brought a conviction backed by plant physiology: the avocado remains active throughout the winter. It doesn't grow with the exuberance of spring, but it continues to respire, move sugars, accumulate reserves, and silently prepare for the next season.

That, in my opinion, was the great legacy of the Israeli school: understanding that autumn is not an end, but a strategic transition. Extending potassium fertilization and maintaining adequate levels of nitrogen in the leaves improved fruit development and, above all, strengthened nutrient reserves. Orchards that adopted this approach increased their production. Not through magic, but through physiological consistency.

More than 25 years have passed, and today the Chilean school of thought—which also exports knowledge abroad—has refined this strategy. We know that fertilization of reserves should begin when the days shorten and the mornings become cold. Starting too early can be a mistake: stimulating late autumn bud break affects floral induction and disrupts the balance, increasing abortions in March and April.

May, June, and July are key months. During this period, the plant assimilates and stores nutrients, instead of using them for vegetative growth. It's a silent but crucial window of opportunity.

However, preparing reserves isn't simply about "applying fertilizer." It's about designing a data-driven strategy. First, estimate the harvest. Then, perform foliar analysis to determine nitrogen and potassium levels. Ideally, complement this with sap analysis—showing nitrates above 1,000 ppm and potassium above 4,000 ppm, without competition from calcium or magnesium—and even innovate by measuring total sugars in the roots, which should exceed 12% by the end of winter.

But there is one essential condition: the root system must be healthy and active. Without functional roots, there are no reserves of any value.

In parallel, the use of biostimulants such as chitosan, anti-stress salicylic acid, and seaweed extracts with amino acids is gaining importance. This isn't a passing fad, but rather a way to maintain active white tips within the mulch, improve absorption efficiency, and prevent losses due to leaching or soil fixation.

There's a fact that should give us pause: it's estimated that around 75% of the nutrients a plant uses, from cauliflower stage to fruit set, come from stored reserves. Chile has cold springs and a root system that awakens slowly. If we don't replenish these reserves in the fall, the plant will flower with a deficiency.

This is why strengthening beneficial microbiology has also gained momentum. Unlike concentrated fertilizer applications—which can cause salinity spikes and imbalances—microorganisms provide more balanced and sustained nutrition. In cold winters, when foliage tends to be dulled by frost and freezing temperatures, orchards with active microbiology show darker, more robust leaves. It's not just about aesthetics: it's about continuous nutritional balance.

Finally, fertilization of reserves is not limited to nitrogen and potassium. Any element below standard should be corrected during this period, especially micronutrients like zinc and boron before flowering. Waiting until August or September, when spring is still cool and the roots are not fully active, is simply too late.

Winter is not a dead time. It is the strategic moment that defines the next season.

The avocado doesn't stop growing; it just slows down. And those who understand this physiological pause and follow it with technical precision enter spring with an advantage.