The life cycle concerning fruit tree crops is characterized by being made up of three stages that have periodic intervals: the first is defined as the juvenile stage, while the second is what is called the maturity stage and, finally, the third is represented from the senile stage.
Each stage can count on a duration that differs according to a large number of endogenous-environmental conditions and has the advantage of changing economic value in relation to the different attention and care from the cultural point of view that are provided to the plant, but also in according to the different production capacity.
The great speed with which one passes from one stage to another is conditioned by the presence of genetic factors, but also technical-cultural and pedo-climatic factors and, for this reason, the speed varies in relation to the species of the plant and the environment. in which it is grown.
The first stage is called juvenile begins with the life of the fruit tree and ends with the moment with the production: the tree can count on an excellent development from the vegetative point of view, but it cannot guarantee the production of fruit.
It is a stage which is also called unproductive, but which can count on a duration that directly depends on the species and on the fact that the latter is a seedling or a spike.
The use of seedlings is characterized exclusively by research to improve the purely genetic profile, so as to be able to develop new cultivars and new rootstocks.
For all those who are lovers of fruit plant cultivation, it is important to underline that, in most cases, astones from one year of age are used.
The duration of the juvenile stage of the seedlings of the pome fruit, specifically we are referring to the pear and the apple tree, goes beyond ten years. As regards the juvenile stage of the stone fruit seedlings, on the contrary, the duration never goes beyond five years and no substantial variations can be found.
In most cases, the free rootstock has the effect of prolonging the unproductive stage in comparison to many other rootstocks that are obtained through the vegetative way.
This particular stage begins when the epigeal part manages to reach a suitable development. Within this stage the vegetative activity undergoes slowdowns (as also occurs within the previous juvenile stage), while the leaves develop in the sense of always having a greater capacity to provide for the synthesis of particular endogenous plant growth regulators, which allow to diversify neutral buds like flowers.
This explains the way in which the first phase of the reproduction cycle begins which, as time passes, turns into an ever more constant fruiting.
The seedlings, in the course of the transfer from the juvenile stage to that of maturity, must face a process that takes the name of Refining, during which the epigeal portion is characterized by the transition from wild to traditional footprints.
The whole activity occurs slowly, starting from the apical part of the plant and ending towards the base of the same.
The basal part of the fruit plant will be able to count on the same characteristics of youth, at least until the moment in which all the epigeal part has reached its stage of maturity.
The last stage concerning the development of fruit plants is called ensiling and is characterized to begin with the gradual aging that affects the root system of the plant.
At the same time there is also a decrease in the absorbent activity: overall, the ensiling stage is characterized by having as its main consequence that of causing a marked weakening of the plant's vegetation activity and slows down the development of most of the plant. of the vital functions of the same.
The tree of the fruit plant is characterized, during this last stage, by presenting a rather limited formation of new shoots, as well as, with the passage of time, the renewal of the fruiting branches also tends to decrease and at the same time, production continues to decline until it becomes sporadic and considerably uneconomical.
The quantity of fruit produced, therefore, is rather scarce and it is no longer convenient for a producer to focus on that particular plant.
Furthermore, the relationship between the mass of leaves and the new organs, within the ensiling stage, changes and causes an exaggerated accumulation of hydrocarbon substances.
This explains why, in all these cases, a decidedly higher leaf mass can be seen compared to a reduced development of new organs.
The annual cycle also changes: the duration of the vegetative period is a few weeks, while the processing phase is lengthened.