Viticulture

thumb|Wine grapes on [[Long Island]]

thumb|A [[vineyard in Brhlovce, Slovakia]]

Viticulture (, 'vine-growing'), viniculture (, 'wine-growing'), or winegrowing is the cultivation and harvesting of grapes. It is a branch of the science of horticulture. While the native territory of Vitis vinifera, the common grape vine, ranges from Western Europe to the Persian shores of the Caspian Sea, the vine has demonstrated high levels of adaptability to new environments, hence viticulture can be found on every continent except Antarctica.

The duties of a viticulturist include monitoring and controlling pests and diseases, fertilizing, irrigation, canopy management, monitoring fruit development and characteristics, deciding when to harvest, and vine pruning during the winter months. Viticulturists are often intimately involved with winemakers, because vineyard management and the resulting grape characteristics provide the basis from which winemaking can begin. A great number of varieties are now approved in the European Union as true grapes for winegrowing and viticulture.

The history of wine dates back at least 8,000 years. Evidence suggests that some of the earliest domestication of Vitis vinifera occurred in the area of the modern countries Georgia and Armenia. The oldest-known winery was discovered in the "Areni-1" cave in Vayots Dzor, Armenia. Dated to BC, the site contained a wine press, fermentation vats, jars, and cups.

The grape vine

The vast majority of the world's wine-producing regions are found between the temperate latitudes of 30° and 50° in each hemisphere.

The grape

The grape is classified as a berry. On the vine, grapes are organized through systems known as clusters. Grape clusters can vary in compactness which can result in long clusters (resulting in the grapes spreading out) or short clusters (resulting in grapes packed together). In some grape species, clusters ripen collectively, which allows them to be harvested together. For others, grapes may ripen individually within a cluster.

Each grape berry contains a pedicel which attaches to the rachis. The main function of the rachis is to allow the grapes to receive their water and nutrients.

The skin of the grape accounts for 5 to 20% of the total weight of a grape depending on the variety. When grape skin ripens, it contains the majority of the aromatic substances and tannin. These factors become important in winemaking for methods including color extraction or aroma dissolution. Although the skin contains the majority of the tannin, small percentages can be found throughout the grape and during all of its developmental stages. However, the tannin's most important role is during the grape's ripening stage as its function is to formulate color and body shape. often collectively referred to as the terroir.

Climate

Climate is the most significant external factor in determining a grape's inherent qualities.

Hot and sunny climates have a frost-free growing season of 200 days or more. These climates allow grapes to ripen faster with higher sugar levels and lower acidity. Cooler climates have a frost-free growing season of around 150–160 days. Cooler seasons force the grapes to ripen earlier, which produces a fresher and more acidic harvest.

Soil

Quality soil is important to allow plants to have better root systems. The growth and health of a vine can be affected if the soil quality is poor. Different grape species prefer various soil conditions, although there are general quality factors. Favorable soil conditions include: aeration, loose texture, good drainage and moderate fertility. Some North American vine species have evolved to show resistance to the mildew.

Downy mildew (Peronospora) thrives in high temperatures and humidity and produces stains on leaves. It can be treated by spraying plants with copper sulphate. Most American vines are resistant, excluding Vitis vinifera.
Fanleaf virus is spread by nematodes that breed in the vine stem. It can lead to deformity, yellowing of leaves, and smaller crop yields. There is no cure for the plant; the best course of action is to remove infected plants and leave the remaining roots to rot.

Sustainability

Sustainable production meets the needs of the present generation without restricting the ability of future generations to meet their own needs. At the end of the 1990s the increased implementation of beneficial and environmentally friendlier production methods, such as "integrated viticulture", "organic-biological viticulture" and "biodynamic viticulture" in the vineyards marked the beginning of a more sustainable production in some regions.

Further measures to improve sustainability have been tried in projects: Examples include the combination with wood production. The use of sheep in vineyards (also known as integrated sheep-vineyard systems) would also be a viable dual-use system and could increase land use efficiency and biodiversity. However, the use of pesticides poses intolerable veterinary risks in many forms of implementation. So these risks severely restrict the temporal and spatial possibilities to introduce sheep in vineyards. The sowing of native wild herbs can generate very positive results for species conservation.

Notes

References

External links

AJEV – American Journal of Enology and Viticulture
GiESCO (International Group of international Experts of vitivinicultural Systems for Co-Operation)
Grape Pest Management Guidelines (IPM) UC IPM Online Pest
SAFECROP – Proceedings of the 5th International Workshop on Grapevine Downy and Powdery Mildew
Guide to Grape Vines
Viticulture on www.extension.org
Institut Agro Montpellier pole vigne-vin