A 10-day advance in full bloom will not translate to 10 fewer days at harvest, but probably 5 to 6 days, while in a season with a very good cold accumulation, an advance of 20 days in full bloom could convert into 10-12 fewer days until harvest.

• An advance of 10 days in full bloom will not translate into 10 fewer days until harvest, but probably 5 to 6 days, while in a season with a very good cold accumulation, an advance of 20 days in full bloom could convert into 10-12 fewer days until harvest.
• For the investigation conducted, 50% hydrogenated cyanamide (HC) and alternative dormancy breakers (RD) (Fiore® y Erger®) were used in the season 2015/2016 of the Santina variety (*Table 2)

A study conducted by the Avium team, in relation to the impact of dormancy breakers on the advancement of harvest and blooming concentration, had as an objective to evaluate the different strategies to confirm if it is possible to achieve homogenization of the initial phenologic states for cherries and eventually a significant advancement in the harvest, which would result in better production profitability.

 “The use of dormancy breakers responds to different objectives proposed from the productive point of view, it is very familiar with the advancement of phenologic states, like blooming, fruit setting, and harvest, primarily in early varieties in early areas that advance or partialize part of the orchard surface, in the case that a great surface extension, and also to advance or synchronize varieties that need to be pollinated with another variety.” pointed out Carlos Tapia, Avium Director.

This is why in season 2015/16 the use of hydrogenated cyanamides and alternative dormancy breakers was evaluated, both each product on its own as well as in sequence. The study was carried out on Santina, a variety that in Chile is considered early, but in reality is a mid-season variety, with an important requirement of cold hours being around 700 hours or more.

The application of Fiore® and Erger® advanced the achievement of full bloom (80% of open flowers) in comparison to control while the hydrogenated cyanamide was consistently what most accelerated the process, considering each product on its own: 10 days (Figure 2). However, the largest impact was achieved when using the products in tandem (treatments 4 and 5), since full bloom was reached 20 days earlier than in the control. It’s important to point out that the investigation was carried out in a year with little cold accumulation.

“Among the products, Chile has always been more familiar with the use of hydrogenated cyanamide, which has the great benefit of being able to advance the phenologic states per se. It’s a product that has the main characteristic of advancement, however for a little more than the past decade it has appeared in Chile RD alternatives. Today commercially as Erger®, Fiore® and Syncron®, which come in some form to supplement the action of these RD, however the great attribution that is generated in the use of these alternatives is primarily the homogenization ability or the synchrony of phenologic states of blooming, the beginning of blooming,” added Tapia.

In relation to the flower period dynamic, it is essential to have a sustained bloom and to be able to concentrate the flowers in the least time possible and so have a larger possibility to achieve a better pollination and later fruit setting, always in consequence to the climatic characteristics of this moment. However during the investigation, in terms of obtaining a blooming concentration (figure 3), the hydrogenated cyanamide did not generate a positive effect on the control. In this variable the other dormancy breakers were more effective, because they do shorten the distance between the beginning and end of the blooming curve thanks to the mode of action related to nutritional factors, since the mode of action of the HCN is of the “abrasive” type in the tissues.

Finally it is worth pointing out that these dormancy breakers have an advancement effect in blooming, color and harvest date in comparison to the control. However, the choice of strategy will depend on the priority that is assigned to the blooming concentration, to the advancement of itself and the intensity degree desired in said advancement.

 “Today there is a lot of information about this so we may conclude that hydrogenated cyanamide on its own generates great action upon the lifting of the phenologic states and alternative RDs, they play a major role in synchrony, rather than the advancement.” the expert emphasized.