The vine is an organism that presents a great biological activity throughout the year and very differentiated according to the season in which we find ourselves.
Each year of its life, a vine goes through different phases, which follow each other in a constant order and which together form the vine's vegetative cycle. In the northern or boreal hemisphere, the shoots begin to grow at the beginning of spring (March or April), finishing the vegetative cycle in autumn (October or November), while in the southern or southern hemisphere the seasons are reversed, with a lag of six months, with the vine sprouting (September or October) and the vegetative cycle ending in spring (April or May).
Below we summarize the different stages of this vegetative cycle:
1. I CRY
It is the first activity of the plant after winter rest. When the temperature of the roots and the soil exceeds 10ºC, the weeping appears that flows through the wounds and pruning cuts. This moment shows the beginning of the activity of the plant, cellular respiration begins, the recovery of the absorption of water and mineral elements. The water and dissolved mineral matter flows upwards through the woody parts of the plant, appearing as tears through the wounds and previous pruning cuts.
The activity of the root, which is the one that begins first, manifests itself successively throughout the plant: it mobilizes the elaborated sap accumulated in it, first in the buds, and then it reaches the entire node and the internodes. The yolk swells up to the separation of the scales that cover them, appearing erased, and then the green organs, forming the "butterfly".
From the shoot, the vine develops the vegetative organs and creates other new organs: roots, buds, grandchildren and clusters, etc. Growth occurs in length and thickness. The temperature and insolation have a major influence on the speed of this phenomenon.
Highlight the existence of dormant buds, because the buds have the potential to develop, but remain dormant due to an inhibitory hormone. So much so that the clusters of flowers (inflorescences) in the dormant buds have their initiation and development in the cycle preceding that of their budding. The formation of the inflorescences or the foliar initiation is carried out in the dormant buds of the previous year around the months of June to July.
The development and maturation of the grapes, that is, the formation and growth of the berries, has its origin and is a consequence of the triple hormonal action and stimulus of pollination, fertilization and seed formation, as well as the contribution of substances nutritious for the plant.
In certain privileged climates, in which there are usually no climatological incidents, the cluster can remain on the vines so that it reaches a higher degree of sugar. It is the so-called overripeness, which is more physical than physiological, because its components are concentrated and the berry loses weight, due to the evaporated water.
5. AUTUMN GROWTH
The stop of growth in summer, which normally happens at the time of veraison, is not always definitive, since the rains at the end of summer can activate growth again. Well into the summer and at its end, the branches appear, small leaves at the tips of the grandchildren, a growth caused by a small activity in the plant's cell multiplication. After the cessation of growth, the anatomical structure of the shoot is modified, acquiring a caramel yellow color.
6. LEAF FALL
When the temperature begins to decrease notably to the vicinity of zero, below which we know that the activity of the plant ceases, its leaves fall; but first, the food materials descend through the woody parts and are constituted in reserves mainly in the arms, trunk and roots of the vine. Leaves turn yellow or red, dry out, and eventually fall off. The vine has entered its winter rest phase. Early winters with frosts can determine an early fall of the leaf, partial or total, harming the accumulation of reserves for subsequent blooms.
7. WINTER REST
After the fall of the leaves, the vine does not present apparent vegetative activity, calling this phase dormancy or vegetative or winter rest. The dormancy of the buds carried by a branch that sprouted the previous year also occurs.