Important factor for earnings and quality of a wine. Without a cut would the Rebstock proliferate unchecked and out of the buds of every last year Triebes build new floors every year, which spread out in a tier-like shape, while the lower floors become wooded. Since the grapes are always produced on one-year wood, the pruning ensures the balance (physiological balance) between yield (generative growth) and growth (vegetative growth), without too much old, unproductive wood being formed. The choice of the appropriate method depends on soil type (fertile-infertile), the training system (Single stick, wire frame, pergola), the climate (damp-dry), the vine (Fertility, inclination to Verrieseln ), of the document, as well as from specific local conditions.
The ideal time for the wintry pruning is the Hibernation (Juice rest); in the northern hemisphere on frost-free days in early spring from January to February, in the southern hemisphere from July to August. After that starts with the expulsion the annual growth cycle of the vine again. There are different methods, there are many in this wine-producing countries individual legal regulations, mainly for the production of quality wines. These may vary depending on the winegrowing region or even in smaller areas (appellations), so are for example in the Champagne four forms allowed. In Friuli, the Simonit & Sirch method developed from a cut only on young wood.
The most elaborate form is the manual cutting of the shoots with the Rebmesser or with the pruning shears, which of course allows an individual work per vine. At the end of March, around 80 to 90% of the annual timber will be removed during the so-called winter cut in January and cut to a maximum of two fruited bats by the end of March at the latest. However, depending on the weather, this can happen very early in December; this is called then Advent cut . It is important that the number of eyes (Buds) is not too high, so as not to overload the vine later by excessive hanging. The number of buds left on the stick depends on its growth power, which depends heavily on the grape variety and the environment.
A vigorous cane leaves more eyes. If the stick is weak (many, but thin, short shoots), less eyes will be left next time. A good unit of measurement is that Timber weight, leaving 30 eyes per kg of cut wood. Depending on the number of eyes of a shoot this is named as a rod, straightener or cones (see under bow ). In order to achieve the best possible ratio between quality and yield (~ 50 hl / ha), the rule of thumb is to leave 6 to 8 eyes (also called 4 to 10) per m² of vine stand space. From the eyes left on the one-year-old wood new shoots of fruit emerge in spring. In the video (click to view) of the DWI is the cutting and baste (Fastening) of a half-bow explained by means of tongs.
Another option is the uniform pruning of all shoots which can also be done by machine. However, this only results in average qualities. In the minimal section ( Minimal Pruned Cordon Trained ) there is only a very small or no manual winter cut. It is practiced mainly in Australia for certain grape varieties. After blossom In June, the summer cut, the foliage walls are usually mechanically cut into shape, laterally projecting shoots are cut, the upright growing shoots culminate, which is the growth in length of the main shoot by cutting the shoot tips completed.
The early removal of the leaves in the grape zone is no longer common, since the still green grapes through the leaf shadow effectively before sunburn can be protected (see below Defoliation ). This can then be done before harvest to simplify the cutting of the grapes and around Botrytis attack submissions. The formerly common Ausbizen , that is the removal of the epicormic shoot (which form massively especially after the summit of the main shoot) is no longer recommended in modern viticulture in principle, since studies have shown that a higher leaf mass by well exposed Geiztriebe the quality of grapes is very conducive to higher sugar storage. However, you have to remove the Geiztrauben early in this case.
The green section on the grape hangings is alternatively carried out in the period July or August, if there is an excessive amount of grapes for the desired wine quality. This vineyard work is called thin out or Green harvest (French vendange vert). This part of the still green grapes before the veraison (Ripening) cut away, resulting in fewer grapes and berries from the leaves of the vine nutrients and sugars need to be supplied, so that more extract is formed and more sugar per grape is stored. This reduction of yield thus increases the quality of the remaining grapes. Also the so-called physiological maturity is thereby positively influenced. The winter buds ripen earlier, the one-year wood lignifies in time, so that the general winter hardiness of the shoots increases. If through vine diseases, hail. frost, Floral damage or the dreaded pest grape the curtain has already been reduced, the thinning can be omitted. Especially at table grapes there is the special technique of curling of to get earlier maturity and larger berries.