Important factor for earnings and quality of a wine. Without a cut it would Rebstock proliferate uncontrollably and from the buds of every last year Triebes build new floors every year, which continue to spread out in tiers, while the lower floors wooded. Since the grapes are only formed on annual wood, pruning ensures the balance (physiological balance) between yield (generative growth) and growth (vegetative growth) without producing too much old, unproductive wood. The choice of the appropriate method depends on soil type (fertile-sterile), the training system (Single stick, wire frame, pergola), the climate (wet-dry), the vine (Fertility, tendency to Verrieseln ), the document, as well as specific local circumstances.
The ideal time for pruning in winter is 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 begins with expulsion the annual growth cycle of the vine again. There are different methods, there are many of them wine-producing countries individual legal regulations, mainly for the production of quality wines. These can vary depending on the wine-growing region or in smaller areas (appellations), for example in the Champagne four forms allowed. In Friuli the Simonit & Sirch method developed that starts from a cut only on young wood.
The most complex form is the manual cutting of the shoots with the Rebmesser or with the pruning shear, which of course enables individual work for each vine. During the so-called winter pruning in January, around 80 to 90% of the annual wood is removed by the end of March at the latest and cut apart from a maximum of two fruit rods. Depending on the weather, this can happen very early in December; this is called the Advent cut . It is important that the number of eyes (Buds) does not become too high, so as not to overload the vine with excessive curtain later. The number of buds left on the stick depends on its vigor, which is highly dependent on the grape variety and the environment.
A growing stick leaves more eyes. If the stick is weakly growing (many, but thin, short shoots), fewer eyes will remain the next time. It is a good unit of measurement Timber weight, 30 eyes are left per kg of cut wood. Depending on the number of eyes of a shoot, it is named as a rod, straightener or cone (see under arc ). In order to achieve the best possible ratio of quality and yield (~ 50 hl / ha), the rule of thumb is to leave 6 to 8 eyes (also 4 to 10 mentioned) per m² of vine stand space. New fruit shoots emerge from the eyes left on the annual wood in spring. In the video (click to view) from DWI is cutting and baste (Fastening) a half-arch explained using binding pliers.
Another option is to cut all of them evenly shoots, which can also be done mechanically. However, this only results in average qualities. With minimal cut ( Minimally Pruned Cordon Trained ) there is very little or no manual winter cutting. It is mainly used in Australia for certain grape varieties. After blossom The summer cut takes place in June, the foliage walls are usually cut mechanically into shape, laterally protruding shoots are cut, the upright growing shoots culminate, which increases the length of the main shoot by cutting off the shoot tips completed.
The early removal of the leaves in the grape zone is no longer common, since the still green grapes effectively through the leaf shadow sunburn can be protected (see under Defoliation ). One can then do this before the harvest to simplify the cutting of the grapes and around Botrytis attack submissions. The previously usual removal , ie the removal of the epicormic shoot (which form in masses especially after the main shoots have peaked) is no longer recommended in principle in modern viticulture, since studies have shown that a higher leaf mass through well-exposed stems drives the quality of the grapes through higher sugar storage. However, in this case you have to remove the miser grapes early.
The green cut on the grape curtain is alternatively carried out in the period July or August if the amount of grapes available is too high for the desired wine quality. This is called vineyard work thin out or green harvest (French vendange vert). A part of the still green grapes is before the veraison (Ripening) cut away, resulting in fewer grapes and berries from the leaves of the vine nutrients and sugars must be supplied so that a total of more extract is formed and more sugar is stored per grape. This reduction in yield thus has a quality-increasing effect on the remaining grapes. Even the so-called physiological maturity is positively influenced by this. The winter buds ripen earlier, the annual wood becomes woody in time, so that the general winter hardiness of the shoots increases. If through vine diseases, hail. frost, Flower 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 ripeness and bigger berries.