Special retraction system; see at vine training.
This refers to various methods of directing the growth of the vine in a very specific way. The vine is a climbing plant (liana) that cannot hold itself upright and therefore needs a climbing aid or support structure. The wild v ines mostly climb up young trees and grow upwards with them. For longer cultivation and for the possible use of machinery, the vines must keep their shape and not (which they would do) grow ever higher. Man therefore began thousands of years ago to shorten the shoots and to use artificial support devices such as stakes or sticks, frames and slats with taut cords or wires. A decisive measure during the winter break (dormant period) is pruning, where the one-year-old wood is pruned. Annual measures (winter pruning, summer pruning and foliage care) counteract the effects of apical dominance in order to also maintain the chosen training system.
There is evidence from pictorial representations that even the Egyptians deliberately grew vines for wine production. A well-known example is the one from the tomb of Chaemwese in Thebes around 1450 B.C. It depicts various wine-making steps such as the grape harvest and fermentation in containers, as well as the loading of a ship with amphorae. The baldachin-shaped overhead vineyard shown in the picture resembles a pergola or trellis vineyard system. Most of the finds come from the city of Luxor in Upper Egypt. A private vineyard is described in inscriptions from the tomb of Metjen, a high official in the 4th Dynasty (2620 to 2500 BC). This official owned a large estate with vineyards in Sakkara in the Nile delta, which are described in the inscription: A very large pond was created, figs and grapes were planted. Trees and grapes were planted in large quantities and a great deal of wine was made from them.
With the Romans, beams were placed on four poles so that a kind of chamber was created. This historical method of cultivation with closed or open chamber construction was still common in German viticulture in the Palatinate at the beginning of the 20th century. The picture on the right shows a medieval depiction of work in the vineyard around the year 1180. This is obviously the form of single-pole training that was probably widespread in many countries at the time.
The criteria for choosing the ideal vine training are, apart from traditional practices, the soil type, the desired yield, the climatic conditions, the grape variety with its vigour and tendency to grow in height or width, the easier control or preventive prevention of vine diseases as well as the requirements of cultivation. A specific system is also often prescribed by wine law. In Champagne, only four specific training systems are permitted, even depending on the grape variety. In the second half of the 20th century, the methods of cultivation changed drastically. The focus was on rationalisation and the requirements of mechanised vineyard management.
The aim of all cultivation systems is to achieve the best possible foliage structure in order to ensure the desired quality and quantity, to achieve labour-economical advantages and to make optimal use of the available environmental resources. Decisive for the selection is, among other things, whether wine grapes are to be produced for winemaking or table grapes for consumption and which harvesting method (manual or mechanical) is used. The individual forms of cultivation are named, among other things, according to the height of the trunk, the distance between the vines, the way in which the newly growing fruit canes are attached, or even according to the inventor (such as Jules Guyot).
The winter Pruning determines where and how many new shoots will grow out of the remaining winter buds in spring, from which the shape of the vine will develop. With regard to the choice of training system, the following points have an influence on the grape or later wine quality:
The height of the grape zone is a factor in the amount of work required and the susceptibility to certain vine enemies. The closer to the ground, the more labour-intensive the care and, in rainy areas, the more likely it is that fungi will get onto the grapes and cause botrytis, downy mildew and black rot in particular. An advantage in northern areas is earlier ripening. The grape zone is between 80 to 130 centimetres and higher. The height has an effect on the exposure (the angle of sunlight) and thus on the distance between the individual vine rows.
The chosen system should have a good foliage wall structure. As many leaves as possible should be exposed to direct sunlight during the day. If the leaves are in the shade, the photosynthesis performance decreases.
The cane spacing for a medium-high training is...