The first physiological change that is experienced is flower induction and that conditions that the bud evolves in the vegetative way to the possibility of being a flower bud. Afterwards comes flower differentiation, which corresponds to the morphological change in the appearance of flower primordia. Then, during the autumn, comes the dormancy stage where the buds close ceasing their development and without any apparent change to finally resume their growth completely in the spring. Knowing these processes allows producers to influence how many flower buds determine the intensity of flowering and therefore the number of fruit obtained per plant.
In the flower induction stage, which is from days 70 to 110 after full flower (DFFB), complex processes are originated that produce stimulus that originates outside of the stem vertex and that induces the formation of flower primordial (Hempel et al., 2000) in stage II of fruit development (Elfvinget al., 2003) until the growth cessation of the sprouts in mid-summer, generally identified with the shortening of the photoperiod. The flower induction moment of the species depends on certain factors like: characteristics of each cultivar, the physiological condition of the tree (which can be affected by the climate), by the own abiotic conditions of the site and without a doubt by the practices and/or culture management done in the orchard. (Thompson, 1996; Guimond et al., 1998a, b; Engin, 2008; Beppu y Kataoka, 2011; Tapia 2018).
Referring to the differentiation of the flower bud (approximately between 110 and 140 DFFB) it is produced in two main periods of time. The start of bloom and the essential development occurring at the end of the summer and beginning of the autumn depending on the climatic zone where the crops are found. After dormancy, the final differentiation of the flower occurs when temperatures rise again in the spring and the phenologic development of the crop begins.
To finish the development of the flower, these must remain in a latent phase in winter where there is a state of latency to support the low winter temperatures, and meet the cold hour requirements of each cultivar.
“The common factor that benefits both processes is the LIGHT. An adequate plant illumination allows them to develop both processes ideally, promoting the formation of flowers in the plants.
Considering this, the lack of light inside the crown may be given by various factors like a combination of rootstock/variety, nutritional program, irrigation programming, pruning that promotes vigor, etc.
It is important that the reading of the plants be perfect at the time of deciding the actions to follow in order to ensure optimal lighting. Within this is the decision of being able to carry out summer pruning that favors the entrance of light to future fruit centers.
In vigorous orchards it is important that once the harvest is finished to ensure the light for these processes, because early pruning is an essential task. However, if pruning is done before January 15, it is very possible that there will be a regrowth of cuts, that in the great number of cases must be assumed and before autumn be able to carry out some work to assure its lignification. If the summer pruning is done after January 15, assuredly the regrowth will be almost none.
For summer pruning to have a direct effect on the use of light, it must be finished necessarily prior to February 10.” pointed out Carlos Tapia, Avium Director.
One of the practices to demonstrate the reproductive state of the orchard and to begin to understand its behavior and in this way be able to generate an orchard history, is the fertility analysis of buds in cherry trees (AdYC) which allows for the obtaining of objective information related to potential productivity of the season and from this point of view make appropriate culture management decisions, like pruning, thinning of cherry buds, and furthermore, to generate practical information for the carrying out of management that promotes an adequate formation of induction processes, differentiation and flower latency.
- Carlos Tapia- Personal Communication.
- “Cherries, botany, production and uses”- Edited by: José Quero-García, Amy Lezonni, Joanna Pulawska and Gregory Lang.