Vine Pruning: An Art in Full Dormancy
Pruning is a crucial stage in vineyard management, which takes place during the vine's vegetative rest phase, also known as dormancy. This period is essential to the vine's life cycle, preparing the vine for the next growing season. Here's a detailed look at this vital process.
What is the vine?
The vine belongs to the Vitaceae family, a group of perennial plants with a liana-like morphology. There are 14 genera in this family, but only the species Vitis vinifera is cultivated for the production of table grapes, raisins and wine. This species comes in a multitude of varieties, known as cépages, which vary according to the wine-growing regions of the world. The vine consists of a trunk, or stock, covered with brown bark which, as it ages, peels off in longitudinal strips. This trunk branches out into several long, flexible branches or twigs, which bear bulges called eyes or nodes. These nodes are the future buds that will develop into pampers. Grapevines have the capacity to elongate very rapidly, reaching up to 5 cm per day.
Why prune vines?
Vine pruning is essential for several reasons:
Ensuring grape production: Pruning regulates grape production by influencing the number of buds that develop. By removing certain shoots or buds, the winemaker can control the vine's yield to optimize grape quality.
Channelling the plant's vigour: By reducing the number of shoots, pruning helps to direct the vine's energy towards the remaining bunches, thus improving the quality of the grapes produced. Proper pruning also helps prevent excessive growth that could compromise the health of the vine.
Reducing the risk of disease: By removing damaged or diseased parts of the vine, pruning reduces the risk of spreading disease and pests. This practice helps keep the vine in good health by preventing overcrowding of the canopy.
Ensuring longevity: Pruning plays a crucial role in the longevity of the vine. By facilitating good air circulation and allowing better exposure to the sun, it contributes to the vine's overall health and future productivity.
Preparing for the birth of the next year's canes : Vines only produce fruit on one-year-old shoots that have grown on two-year-old wood. As a result, pruning is a two-year operation: it determines which shoots will bear next year's bunches of grapes, while controlling the grape load for each stock.
Types of pruning
Pruning techniques vary according to grape variety, soil, climate and local legislation. Here's an overview of the two main techniques:
Short pruning: This method involves leaving just a few buds on each shoot, resulting in more concentrated and often higher-quality production. It is commonly used for grape varieties that need fewer buds to produce high-quality grapes.
Long pruning: This technique leaves more buds on each shoot, allowing for more abundant production. It is adapted to grape varieties that can bear a greater load of grapes and benefit from such an approach to optimize yields.
The pruning process
Pruning generally begins in November, after leaf fall, and continues until March, when the vine's "weeping" signals the start of sap recovery. At this point, drops of sap appear at the tips of the branches, giving the impression that the vine is crying. This marks the end of dormancy and the start of the new growing season.
During pruning, the winemaker uses tools such as secateurs to eliminate unwanted shoots and select the most promising buds. The number of grapes per vine, known as the load, is determined by the very nature of the vine. A young, vigorous vine can bear a heavier load than an old one. However, the winegrower also limits the number of fruits on young vines to ensure optimum grape quality.
In short, pruning is a delicate and technical operation that requires a thorough knowledge of the vine and its needs. It is essential to guarantee the production of high-quality grapes, while ensuring the health and longevity of the vines for years to come.