41 B

History of Origin and Economic Significance

The grape rootstock Chasselas × Berlandieri 41B was selected in France in 1882 by scientists and breeders Millardet and de Grasset by crossing the European variety Chasselas with the American species Berlandieri. This variety is recognized as the best rootstock for highly calcareous soils and has become widespread in European countries—France, Italy, Bulgaria (where it occupies up to 40% of the total area of mother vineyards), as well as in the USSR: in Ukraine, Moldavia, and Georgia. The variety is of great production value for the Transnistrian districts of the Vinnytsia region, since due to the heavy snow cover, the roots of the rootstock are not severely damaged by winter frosts. In comparison with other recommended rootstocks (3306, 3309, 101-14, 420A, and Rupestris du Lot), the variety Chasselas × Berlandieri 41B stands out for the most vigorous growth of the bushes and the earliest start of shoot ripening, outstripping Berlandieri × Riparia 5BB and 420A in this regard by ten days, which partially accelerates the ripening of the grape varieties grafted onto it. A characteristic feature possessed by the rootstock Chasselas × Berlandieri 41B is the development of thick, fleshy roots, due to which the bushes develop slowly at first. However, once the vineyards become established, good development and high productivity of the European scions are ensured.

Soil Recommendations and Resistance to Environmental Factors

The rootstock variety Chasselas × Berlandieri 41B successfully develops on humus-carbonate and clay-carbonate soils. The chlorosis resistance of the variety is high: it surpasses all rootstock grape varieties recommended in Georgia, developing well on soils containing up to 60% lime, and its resistance to lime was rated with the highest score of 40 on the Galet scale. Agricultural regulations recommend using the rootstock Chasselas × Berlandieri 41B for the most calcareous soils with a pH reaction above 7.0–8.0. Thanks to its powerful, deeply penetrating root system, the drought resistance of the bushes is high and exceeds the performance of Riparia × Rupestris hybrids. At the same time, the variety Chasselas × Berlandieri 41B possesses very low frost resistance of the roots (they are severely damaged at a temperature of minus 6–7 °C), being inferior in frost resistance to the rootstock Rupestris du Lot. In severe snowless winters in the south of Ukraine, freezing of roots down to a depth of 45 cm was recorded, which was the main reason for its limited distribution in that region.

Morphological Description of the Rootstock Variety Chasselas × Berlandieri 41B

The botanical description of the rootstock Chasselas × Berlandieri 41B was compiled from the materials of the Vazisubani experimental base of the Research Institute of Horticulture, Viticulture, and Winemaking of the Georgian SSR. Identification of the variety in vineyards is carried out according to the following primary characters:

• Young shoot (tip): The tip of the young shoot and the first barely unfolded leaves are densely covered with white felt pubescence with a faint pink margin along the edges. The second and third leaves are covered with cobwebby pubescence on top and felt pubescence underneath, and are colored greenish-yellow with a bronze tint. The shoot axis is ribbed, covered with cobwebby pubescence, and is violet-green with a brownish-red tint on the sunny side. The tendrils are large and weakly pubescent.
• Mature leaf: The leaves are rounded, three- or five-lobed, weakly dissected, almost entire. A characteristic feature of the variety is the upturned margins of the lobes (though turned-down margins of the lobes are noted in the primary diagnostic characters). The upper surface is light green, the veins are pale green with a barely noticeable fuzz. The lower surface of the leaf is pale green, rough, and the veins are covered with bristly pubescence. The upper sinuses are small, barely outlined or in the form of an incoming angle; the lower sinuses are often completely absent.
• Petiole sinus: Open, brace-shaped or lyre-shaped with a rounded base.
• Teeth: At the ends of the lobes, the teeth are triangular with a sharp apex. The marginal teeth are triangular with convex sides and a rounded apex, as well as dome-shaped.
• Petiole: Shorter in length than the median vein of the leaf, colored light brown, and pubescent with cobwebby fuzz.
• Flower: Functionally female flower type, with stamens curved under the pistil.
• Cluster and berry: The cluster is small, cylindrical-conical in shape, and loose in structure. The berry is small, rounded, and black in color.
• Annual shoot: The cane is sturdy, gray-green with dark brown stripes along the internodes, and strongly ribbed. The shoots are characterized by uniform thickness.

Features of Agricultural Practices in Nursery Management

The variety Chasselas × Berlandieri 41B forms well-ripening shoots with a small number of lateral shoots. In the mother vineyards of Georgia, five-fold lateral shoot removal significantly increases the yield of first-grade cuttings (up to 102,625 pieces per hectare). The yield of 110-cm cuttings suitable for grafting in Eastern Georgia averages 60 thousand per 1 hectare (average diameter 6.57 mm), and in Western Georgia—82 thousand per 1 hectare (diameter 6.85 mm). The variety Chasselas × Berlandieri 41B demonstrates good indicators of callusing and graft compatibility with local standard varieties and good rooting of cuttings, but these properties are slightly lower than those of Riparia × Rupestris hybrids. In the south of Ukraine, the variety roots perfectly and does not yield to such rootstocks as 101-14, 3309, and 5BB in terms of the output of first-grade saplings, while under Georgian conditions, the output of saplings is lower than that of the specified varieties, but higher than that of the rootstock 420A. The root resistance to the root form of phylloxera is good and quite sufficient (rated 15 points on the 20-point Viala and Ravaz scale). Resistance to the foliar form of phylloxera is insufficient (galls are formed on the leaves), but the variety Chasselas × Berlandieri 41B is less damaged by it compared to Riparia × Rupestris hybrids. The resistance of the variety to downy mildew is also insufficient: in certain years with heavy rainfall, the vineyards require treatment against downy mildew, while in normal years, the leaves and shoots are not affected.