«From the second half of June there was a kind of acceleration of the accumulation of cold, with days in which it accumulated practically 24 hours a day and we ended with a very good accumulation of cold, of very good quality..»
On July 31, the period of cold hour accumulation for cherry orchards officially ended, a factor of great importance in the productive cycle of deciduous species. Quantity, quality, size and condition of the fruit depend largely on this important process, which begins with the start of physiological dormancy, recognized as 50 percent leaf fall (yellow leaf = leaf fall), and which generally occurs in early May.
Each variety has a different requirement for number of chilling hoursHowever, compliance is crucial, as it is directly related to the use of reserves that the plants have to start the following season.
For the second consecutive year, Avium's technical team carried out a detailed monitoring and reporting of the Evolution and comparison of the accumulation of cold hours, 2021-22 season, based on the classic model, i.e. below 7.2ºC; the data obtained allow us to draw a positive conclusion on this important indicator for cherry orchards.
“If we analyze the dynamics of cold accumulation this season, we can say that in the first part we had a poor accumulation, quite below the average of the last 10 years depending on the area, and we were a little worried until June 10-15 regarding the dynamics of accumulation. However, from the second half of June there was a kind of acceleration of cold accumulation, with days in which it accumulated practically 24 hours a day and we ended with a very good accumulation of cold, of very good quality, concentrated between June 15 and July 10, which is the cold that accumulates in the central part of dormancy,” explained Avium's Technical Director and specialist advisor in cherry production, Carlos Tapia.
The hours accumulated during this period of dormancy, called endodormancy, which is the full lethargy of the plants, are the most important. In an ideal scenario, between June 1 and 30, there should be an accumulation of at least 250 hours of cold, an amount reached in years of good productive potential of cherry orchards.
“This season it is recognized and concluded that a good amount of cold accumulated during this period, ending in many areas of Chile above the average of the last 8 or 10 seasons, without being the best year of cold accumulation, but in general, if we look at the accumulation curves, it ended with a good number. This means that within the “check-list” of factors that influence the productive potential of the cherry tree, we have a “check” in terms of cold accumulation and the plants will come out of dormancy with a good base, where the reserves they have accumulated in the summer months should be expressed well.", Tapia indicated in his assessment of the accumulation of cold hours, 2021-22.
The cherry production specialist and Master of Science in fruit physiology, also referred to the productive potential of the recent season, an indicator that must be kept in mind: “We must consider that orchards in general are coming from a year of high production (called an “on” year), so we have to recognize that there is probably wear and tear on the plant compared to the previous season and it could be a year of less fruit set or lower production potential, which is not necessarily bad news, because that will improve the quality and condition of the fruit.”
Although the first goal of the coming season has been met, with an accumulation of cold hours sufficient and even higher than the last 8 or 10 seasons in some areas of the country, the race has just begun: “The accumulation of cold is a factor in the productive potential, but there are also other factors that also influence it, such as post-dormancy temperatures, temperatures at the beginning of spring for all the physiological processes of flowering, pollination, fertilization and setting, and after that the development of the fruit, absence or presence of frost in spring that can reduce the potential due to possible damage, the flight of bees and the viability of the flowers to be fertilized, but also the absence or presence of rain in a year like this, I think it is more of a benefit than a threat because we need to hydrate the soil, so that the plants can better express their reserves and impose that on the potential,” Tapia concluded.
