Foil process

In viticulture, a common facility or operation for the cultivation of grafted vines and rootstocks, similar to a tree nursery. Often a grafting operation is also attached. An important basis for cultivation or "training" is light to medium-heavy soil rich in humus, which enables rapid rooting. The main prerequisite is a sufficient supply of potassium (potassium salts) and magnesium. The plant must be less susceptible to frost, warm and protected from the wind, and free from virus-transmitting nematodes (threadworms).

Vegetative propagation is the only way to ensure that the new vines have exactly the same genes and therefore characteristics as the original vine. Generative propagation by sowing and growing grape seeds is therefore out of the question. The basis for the later vine are two components, namely the scion (upper part) and the rootstock (lower part). Both are grown separately and only become a plantable cutting through grafting, forcing and subsequent training.

Scions (tops)

The scions are obtained from clones that have been observed for several years in officially recognised productive vineyards and tested for their positive viticultural characteristics (clone selection). The best of these with special requirements are used as so-called mother vines or basic planting material after approval. From these, 80-centimetre-long annual canes are cut off. Pruning is carried out at the end of December to mid-January to prevent bud damage caused by frost. The canes must have at least seven graftable eyes, some with long internodes such as the Blaufränkisch (Lemberger), Trollinger or Dornfelder varieties only have five.

Up to 50 scions can be obtained from a mother vine. Until further use, they are stored in cold storage rooms at 1 to 2 °Celsius,...