A rootstock (also Millardet et de Grasset 420 A); look there.
Designation for the lower part or rhizome of a grafted vine that of a rainbow resistant American vine comes. In the finishing On top of this is the top (Edelreis) of European varieties of the species Vitis vinifera grafted. The main reason for such grafting is the low susceptibility or resistance the roots of American wild species against the subterranean stages of the phylloxera, or against the formed by the phylloxera attack on the roots Nodositäten and tuberosities (Growths).
With regard to viticulture suitability Unterlagsrebsorten must also meet other breeding requirements. That's low susceptibility to both mildews, slight inclination too chlorosis, great resistance against bacteria and virus, good wood structure and wood maturity, good adaptation (Compatibility) to diverse and difficult soil types such as dry soil or calcareous soil, good absorption of the nutrient from the ground, as well as good Pfropfaffinität to the grafted grape variety without the promotion of Verrieselns, A good coalescence of the two alien tissues at the grafting point and the harmonious matching of the growth characteristics of the grafted grape variety with those of the Unterlagsorte usually ensure a good instinctuality and grape quality with consistently high earnings of the vine.
The vast majority of the documents used in European countries are descendants of the three American wild species crosses Vitis berlandieri x Vitis riparia, Vitis riparia x Vitis rupestris and Vitis berlandieri x Vitis rupestris. Decisive factors contributed to the pioneering research of the US botanist Thomas Volney Munson (1843-1913) at. A 1989 certified substrate with complete phylloxera resistance was provided by Dr. med. Helmut Becker (1927-1990) from a cross Vitis riparia x Vitis cinerea created. He named her after the German oenologist dr. Carl Börner (1880-1953). Not every rootstock is for the different ones soil types, Site conditions, varieties and growth requirements are equally suitable.
Therefore, there are official recommendations, which base with which grape variety (top) on which soil harmonizes best and brings the required results. The cuttings rooting of most of the rootstock is without any problem, but it is best still rooted in the cuttings of the European vine Vitis vinifera. Therefore, the European portion of a grafted vine cuttings should not be buried in the ground. The subspecies with introductions of Vitis cinerea var. Helleri (known under the old name Vitis berlandieri) or Vitis champinii According to experience badly root, so that the cutting ends with the growth hormone auxin coated to induce rooting.
As well as Quality wine-grape varieties underlaid vines are also approved or classified by the provincial authorities (this can also be different for the wine-growing region). Some (latent) vine diseases (see also under Vine enemies ) can be extensively propagated in grafting and cuttings propagation, for example when plant material infected with viruses or bacteria (underlay or grape) is used. The effects are often only visible on older sticks. Therefore, the use of the most healthy, virus-free planting material in the EU is required by law. In this regard, proof must be provided by a standardized procedure (see Certification of vines ).
François is one of the most well-known breeders of successful rootstocks Baco...