By:
Carlos J. Tapia T. Technical Director Avium and Co-founder of SmartCherry.
Emilio Martinez Agricultural Engineer. Avium
Bruno Tapia Agronomist. Avium
Edited by Daniela Balagué. Journalist. Communications Manager Avium
The use of hydrogenated cyanamide alone generates a great action on the advancement of phenological states and alternative dormancy breakers (RD) have a great participation in homogenization rather than in advancement.
The impact of dormancy breakers for the advance of harvest and concentration of flowering has been and will continue to be a subject of study by researchers who are constantly seeking to evaluate different strategies that can be replicated in a cherry orchard, to determine responses to the advance and/or homogenization of the initial phenological states (budding and flowering); resulting in an advance or homogenization of harvest, which combined with the season, could eventually translate into better business profitability.
In search of this answer, the Avium team conducted a significant study during the 2015/16 season on the use of hydrogenated cyanamides (HC) and alternative dormancy breakers (RD), both each product alone and in sequence, in order to find a response to the impact mentioned above (Table 2). The study was carried out on the Santina variety, which, although considered early in Chile, is actually a mid-season variety, with a significant chilling hour requirement of around 700 hours or more.
“The use of dormancy breakers responds to different objectives proposed from a productive point of view. It is very familiar with advancing phenological states, such as flowering, setting, and harvest, mainly for early varieties and in early areas to advance or partialize part of the surface of an orchard, in the case that there is a large area, and also to advance or synchronize varieties that need to be pollinated with another variety.” said Carlos Tapia, Director of Avium.
Table 2: Treatments using different dormancy-breaking application strategies.
Some of the most important results of the study were that the application of Fiore® and Erger® advanced the attainment of full flower by 8 days (80% of open flowers) compared to the control, while hydrogenated cyanamide was consistently the one that accelerated the process the most, considering each product on its own: 10 days (Figure 2). However, the greatest impact was achieved by using the products in tandem (treatments 4 and 5), since full flowering was reached 20 days earlier than the control. It is important to highlight that the research was carried out in a year with little accumulation of cold (very similar to the current season and on a variety such as Santina that has a medium/high requirement of winter cold). These results would undoubtedly be much more accurate in a year with greater cold and with a variety with lower requirements than those presented.
“Among the products, Chile has always been more familiar with the use of hydrogenated cyanamide, where its great benefit is to achieve an advance in the phenological states per se. It is the product whose main characteristic is to advance, however, a little more than a decade ago, alternative RDs have appeared in Chile. Today, commercially, such as Erger®, Fiore® and Siberio® and Syncron®, which come in some way to supplement the action of these RDs, however, the great attribution that is generated in the use of these alternatives is mainly the capacity for homogenization or synchrony in the initial phenological states, even having a great power of action on the vegetative buds generating quite a few more flowerings accompanied by leaves.” Tapia added.
In relation to the dynamics of the flowering period, it is essential to try to achieve sustained flowering and to be able to concentrate the flowers in the shortest possible time and thus have a greater possibility of achieving better pollination and subsequent fruit set, always in accordance with the climatic characteristics of this moment. However, during the research, in terms of obtaining a concentration of flowering (figure 3), hydrogenated cyanamide did not generate a positive effect on the control. In this variable, the other dormancy breakers are more effective, since they do shorten the distance between the beginning and end of the flowering curve thanks to their mode of action related to nutritional factors, since the mode of action of CNH is of the “abrasive” type in the tissues.
Over the last year, studies have been carried out on late applications of alternative RD, in the month of August, and which have shown interesting indicators. However, these applications can generate greater risks of damage from spring frosts on the floral primordia and, in the case of the spur shoot, can cause the death of the vegetative bud, which would be detrimental to the renewal of this reproductive organ.
Although this type of strategy is in the validation stages, preliminary improvements in production indicators can be observed, positively impacting the final result. It should be noted that no impact of early flowering is observed, rather this type of product is related to a nutritional action and, from our point of view, with a lot of synergy in the accumulation of cold hours and accumulated degree days at the time of application.
Finally, in conclusion, the expert emphasizes that “Today, with a lot of information on the subject, we can conclude that hydrogen cyanamide alone generates a great action on the lifting of phenological states and alternative RDs, they have a great participation in synchrony, rather than in advancement.”.
It is important to highlight that all dormancy breakers have an effect on early flowering, colour and harvest date compared to the control. However, the choice of strategy will depend on the priority assigned to the concentration of flowering, the advance of flowering and the degree of intensity desired in said advance. Therefore, the strategy must be evaluated every season, combining productive potential, agroclimatic, logistic-operational and commercial factors to achieve the objectives proposed by each producer.
