Viticulture involves practices such as soil preparation and tilling, growing and planting of varieties, trellising and pruning of vines, and combating disease.
Along with the type of variety chosen, soil, climate and winemaking techniques, these vital practices are the main factors which determine the quality and character of a wine.
When a vineyard is established, it is important that a thorough study is made of the soil and climatic conditions to ensure that the most suitable cultivation methods are chosen. Thorough soil preparation is essential to create an environment for plant roots in which air and moisture are kept in the right proportion to solid material, and to ensure that there is sufficient nutrition to promote the best growth and production.
The choice of variety will depend on the composition of the soil, the climate, where the vineyard is situated and what kind of wine is desired. Varieties bearing heavier harvests are generally planted in areas under irrigation. In cooler regions, and where the soil is not very fertile, varieties which grow less densely are planted, as well as those that produce smaller but higher quality harvests.
Previously it was generally accepted that the higher the yield, the lower the quality of wine and vice versa. Research has shown this approach is not quite correct. Of great importance is the balance between leaves, which function effectively because of good exposure to sunlight and the quantity of grapes harvested. When there are not enough functioning leaves to sustain a large crop, the quality will be lower.
Vines are climbing plants and are suitable for trellising. Stronger growing plants are usually trellised and can carry heavier harvests. As bunches hang higher off the ground, there is less chance of rot as a result of damp. The decision whether to trellis at all, and the type of trellising system used, is determined by the soil potential, variety, climate, growth and vigour of the vines. In areas where frost damage is prevalent trellising is required, while dry land vineyards with a weaker growth are often not trellised.