THE VINE

The Vine

Overview of Grape Varieties

• Thousands of grape varieties exist globally, exhibiting a diverse range of characteristics, flavors, and adaptations to various climatic conditions. Each variety holds distinct traits important for winemaking, influencing the final taste and quality of the wine produced.

Vine Species

• Key Species in Viticulture:

• Vitis vinifera: This species is the cornerstone of the wine industry, accounting for approximately 99% of the world’s wine production. Its rich history in winemaking dates back over 8,000 years, with the earliest evidence found in ancient civilizations of the Middle East. The wide variety of cultivars derived from Vitis vinifera allows for a multitude of flavor profiles, ensuring its prominence in global wine culture.

• American Vines: There are three primary species of American vines, primarily Vitis labrusca, Vitis riparia, and Vitis aestivalis. While these species possess flavors that are often considered unsuitable for traditional winemaking, they play a crucial role in viticulture as rootstocks due to their high resistance to Phylloxera, a devastating pest that attacks vine roots.

Grape Varieties and Their Importance

• Characteristics:

• Each grape variety presents unique differences in color (e.g., white, red, rose) and flavor profiles, influenced by numerous factors including terroir (environment), climate, and growing conditions. Additionally, variations in budding times, ripening stages, and inherent disease resistances play critical roles in the cultivation and management of vineyards.

• Propagation Techniques:

• Cuttings: This widespread propagation method involves taking a section of a shoot, which when planted can develop into a new plant, preserving the genetic traits of the original vine. It is the primary method used in nurseries to propagate desired vine varieties.

• Layering: This technique entails bending a cane to the ground and burying it in soil, allowing it to take root while still connected to the parent vine, further retaining its characteristics.

Clones and Genetic Variation

• Clones:

• Clones are genetically identical vines derived from a single parent vine. Variations among clones arise due to mutations, which can enhance qualities such as flavor, aromatic intensity, or resistance to diseases. The practice of clonal selection focuses on identifying and propagating these beneficial mutations to develop superior vine stocks.

• Examples of Mutations: Clonal mutations have given rise to different versions of popular grape varieties such as Pinot Noir, Pinot Blanc, and Gruner Veltliner, each adapted to specific growing conditions and consumer preferences.

Creating New Vine Varieties

• Researchers engage in the crafting of new grape varieties aimed at enhanced climate resilience, improved disease resistance, and increased quality and yield. Techniques such as cross-fertilization are employed to combine desirable traits from different grape varieties. When seeds from these crosses are planted, they carry unique genetic material from both parent varieties, leading to a broad range of variability.

• The progressive use of genetic markers allows faster identification and selection of desired traits, facilitating effective breeding practices in the quest for optimal grape varieties.

Crossings and Hybrids

• Crossing: This process involves creating a new variety from two parents within the same species, typically within Vitis vinifera. Notable examples include Cabernet Sauvignon, which originated from the crossing of Cabernet Franc and Sauvignon Blanc.

• Hybrids: These arise from crosses between different species, often incorporating American vines. While many hybrids are deemed unsuitable for fine winemaking due to flavor variances, a select few like Vidal have gained acceptance in the industry, primarily serving as rootstocks for their resilience.

Phylloxera and Rootstocks

• Phylloxera:

• An invasive pest that has wreaked havoc on vineyards worldwide by weakening and ultimately killing Vitis vinifera plants. Its impact has led to a catastrophic decline in vineyards, prompting the need for effective solutions.

• American vines, due to their evolutionary adaptations, possess inherent resistance to Phylloxera, making them invaluable in the fight against this pest.

• Rootstocks:

• Grafting V. vinifera onto resistant American or hybrid rootstocks is now a standard practice to ensure the survival of the vines and preserve specific flavor profiles. These rootstocks also offer additional benefits, such as combating nematodes and enhancing drought resistance.

• Grafting Techniques:

  • Bench Grafting: This automated method efficiently joins rootstock with V. vinifera, offering rapid propagation options.

  • Head Grafting: A practical technique for transitioning between grape varieties in existing vineyards by attaching new varieties to the trunk, making it an economical choice to quickly adapt to market demands.

Anatomy of the Vine

• Vines consist of four main structural sections: green parts, one-year-old wood, permanent wood, and roots, each contributing to the overall health and productivity of the plant.

The Green Parts of the Vine

• Tendrils: These specialized structures help vines clasp around supports, providing stability as they grow.

• Buds: Embryonic shoots hold the potential for future growth, functioning as critical components for the next year’s harvest.

• Leaves: The leaves serve as the vital organs of photosynthesis, providing nourishment essential for the vine’s health.

• Flowers/Berries: The reproductive organs of the vine, where successful pollination leads to the formation of grape bunches, crucial for fruit development.

One-Year-Old Wood and Permanent Wood

• One-Year-Old Wood:

• These are the vegetative shoots that have emerged from the previous year’s growth. Proper management practices are essential for maximizing fruit production, with careful differentiation between canes (which carry more buds) and spurs (which have fewer buds) depending on specific pruning strategies.

• Permanent Wood:

• This section comprises the trunk and arms of the vine, shaped through pruning techniques over the years, establishing the framework for the vine's growth and productivity.