Understanding vine phenology and its stages

Every year, the vineyards undergo a mesmerizing transformation, gracefully changing with each passing season. This ever-evolving spectacle of nature is central to viticulture, the art and science of wine production. However, the key to unlocking the vine's full potential and appreciating its beauty lies within an often-overlooked field known as phenology. In this article, we will delve into vine phenology, examining its stages and importance in viticulture and how it can help vine growers adapt to climate change.

Phenology, an underrated yet essential science

Phenology is the scientific study of how living organisms, such as grapevines, evolve and adapt to their climatic and environmental conditions. This field of study meticulously observes changes in vine development influenced by various factors, including temperature, light, humidity, soil, and photoperiod. These alterations, known as phenological stages or phases, occur not only in vines but also in any living organism responding to external stimuli.

Phenological studies of grapevines hold paramount importance in determining optimal timelines for performing necessary agricultural tasks. From sowing and fertilizing to pruning and harvesting, phenology informs every step. Furthermore, it also plays a crucial role in preventing the onset of pests and diseases, which often have strong seasonal characteristics.

The vinicultural impact of phenology

The vine's lifecycle, heavily dictated by phenology, has a profound influence on the wine industry. Did you know that the timing of harvest can significantly impact the flavor, aroma, and acidity of grapes? This intricate knowledge allows us to fully utilize the potential of vineyards.

Phenology, a tool against climate change

Phenology is also instrumental in understanding the implications of the climate crisis on viticulture. As rising temperatures increasingly threaten crop quality and yield, adapting to climatic changes, such as opting for high-altitude vineyards, becomes indispensable. Phenology equips us with the knowledge to make these necessary adjustments.

Phenological stages of the vine: a year-long journey

Below, we explore the various phenological stages of the vine, capturing the vine's journey from a dormant winter bud to the coveted grape harvest.

• Winter Bud (A): A period of latency where the vine sheds its leaves and suspends its vegetative activity, becoming highly resistant to cold.
• Weeping (B1): As the climate warms, the vines resume their activity, with the pruning cuts starting to exude sap.
• Swollen Bud (B2): During this stage, the buds progressively thicken.
• Green Tip (C): Rising temperatures cause the buds to burst open, leading to the emergence of tiny green shoots.
• Incipient Leaves (D): The first leaves start to form from the shoots but remain closed.
• Extended Leaves (E): Gradually, the leaves unfurl, revealing the distinctive characteristics of the vine variety.
• Inflorescence (F): The future flower's form begins to develop, becoming subtly visible.
• Separated Clusters (G): The clusters unfold, and the compact structure of the flowers becomes apparent.
• Separated Floral Buds (H): The clusters and flowers fully develop during this phase.
• Beginning of Flowering (I1): The floral organs are exposed as the corolla sheds, marking the vine's blooming phase.
• Full Flowering (I2): The stamens (male organs) and pistils (female organs) of the vine fully mature.
• Setting (J): Post-reproduction, grape berries begin to form in the fertilized ovaries.
• Pea-sized Berry (K): The grape berries grow gradually until they reach the size of a pea.
• Closing of the Cluster (L): The cluster's development leads to berry growth and the thickening of the woody structure.
• Beginning of Veraison (M1): Berry by berry, the clusters start acquiring their characteristic color.
• Full Veraison (M2): The clusters are fully formed, and the fully-colored grapes are coated with a waxy texture called bloom.
• Ripening (N): When the grapes reach optimal maturity, it's time for the harvest.
• Beginning of Leaf Fall (O1): Gradually, the vine's leaves start to degrade and turn yellow.
• Full Leaf Fall (O2): The leaves, now completely dry, finally fall off, and the vine is ready to return to the initial phenological stage: the winter bud.

The captivating world of viticulture would be incomplete without the fundamental understanding provided by vine phenology. By unveiling the intriguing secrets of this science, we can not only improve the yield and quality of our vineyards but also ensure their resilience against an ever-changing climate. So next time you visit a vineyard, take a moment to appreciate the natural spectacle that vine phenology orchestrates.