A rootstock (also Millardet et de Grasset 420 A); look there.
Term for the lower part or rhizome of a grafted vine by a phylloxera resistant American vine comes. In the finishing is on this the top (noble rice) of European varieties of the species Vitis vinifera. The main reason for such grafting is the low susceptibility or resistance the roots of American game species against the underground stages of the phylloxera, or against those formed by the phylloxera infestation at the roots Nodositäten and tuberosities (Growths).
With regard to the suitability for viniculture, underlay grape varieties must also meet other breeding requirements. That is low susceptibility to both mildews, low tendency to chlorosis, great resistance to bacteria and virus, good wood structure and maturity, good adaptation (Compatibility) to diverse and difficult soil types such as dry soil or limestone soil, good absorption of the nutrient off the ground, as well as good ones Pfropfaffinität to the grafted grape variety without the promotion of Verrieselns, A good overgrowth of the two alien tissues at the grafting point and the harmonious coordination of the growth properties of the grafted variety with those of the rootstock usually ensure good growth and grape quality at a uniformly high level 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. The groundbreaking research by the US botanist Thomas Volney played a key role in this Munson (1843-1913) at. A document approved in 1989 with complete phylloxera resistance was developed by Dr. Helmut Becker (1927-1990) from a cross Vitis riparia x Vitis cinerea created. He named it after the German oenologist Dr. Carl Börner (1880-1953). Not every type of pad is for the different soil types, Location conditions, noble varieties and growth requirements equally suitable.
For this reason, there are official recommendations as to which surface works best with which grape variety (top part) on which soil and brings the required results. The cuttings Most rootstocks are rooted without any problems, but the cuttings of the European grapevine Vitis vinifera are still best rooted. Therefore, the European part of a grafted vine cutting should not be buried in the ground. The document types with crossings from Vitis cinerea var. Helleri (better known under the old name Vitis berlandieri) or Vitis champinii experience shows that they root themselves poorly, so that the cuttings ends with the growth hormone auxin be brushed to induce rooting.
As well as Quality wine-grape varieties Supporting vines are also approved or classified by the state authorities (this can also vary depending on the wine-growing region). Some (latent) vine diseases (see also under Vine enemies ) can be widely distributed in the grafting and propagation of cuttings if, for example, plant material infected with viruses or bacteria (underlay or noble rice) is used. The effects are often only visible on older sticks. That is why the use of healthy, virus-free planting material is required by law in the EU. In this regard, evidence must be provided by a standardized procedure (see under Certification of vines ).
François is one of the best-known breeders of successful vines Baco, Helmut...