RR 101-14

History of Origin and Economic Significance

The grape rootstock Riparia × Rupestris 101-14 was bred in 1882 by breeders Millardet and de Grasset in France, from where it subsequently became widespread in many viticultural regions of the world practicing grafted culture. In the viticultural enterprises of the USSR, this variety occupied a dominant position: in Ukraine, the rootstock Riparia × Rupestris 101-14 accounted for more than 60% of the total area of all rootstock mother vineyards; in Moldavia, according to the 1960 census, it represented about 50% of the registered vines, and in Georgia, it occupied around 20.4% of the mother vineyard areas. The uniform thickness of the shoots along their entire length makes the variety Riparia × Rupestris 101-14 a highly valuable material for mechanized grafting. Grapevines grafted on this rootstock are characterized by outstanding longevity and stable production—in Moldavian conditions, highly productive plots planted more than 50 years ago have been recorded. The vigor of the bushes is medium; in terms of overall vigor and growth mass, the rootstock variety Riparia × Rupestris 101-14 is slightly inferior to Riparia Gloire.

Morphological Description of the Rootstock Variety Riparia × Rupestris 101-14

The morphological characters of the variety were recorded at the collection plots of the Moldavian Research Institute of Horticulture, Viticulture, and Winemaking. The primary botanical characteristics include the following features:

• Young shoot (tip): The tip is relatively large, light green, and completely glabrous. Young leaves are light green with a barely noticeable golden tint, almost entire, and gutter-shaped. The upper surface is glabrous and shiny, while the lower surface has weak bristles along the veins. The petioles of the first leaves are pubescent, with the pubescence weakening later on.
• Mature leaf: The leaves are of medium size, rounded, practically entire or with three weakly outlined lobes (the lateral lobes are distinguished only by more developed teeth). The leaf blade is dense, curved in the shape of a gutter, with wavy margins. The upper side is slightly bullate due to the veins being depressed into the leaf flesh, and the main veins have a reddish tint at the base. On the lower side of the leaf, there is bristly pubescence along the veins and in the angles of their divergence.
• Petiole sinus: Wide, open, brace-shaped. In leaves forming closer to the end of the vegetative period, the sinus becomes lanceolate.
• Teeth: Saw-toothed with a widened base and white points at the apexes. The teeth at the ends of the central and upper lateral lobes are distinctly elongated into a sharp point.
• Petiole: Equal in length to the median vein of the leaf or shorter. It is colored green with a wine-red tint and covered with sparse bristly pubescence, which almost completely disappears towards the autumn period.
• Flower: Functionally female flower type. There are five stamens, and their anthers are turned downwards. The ovary is pear-shaped with a cylindrical style. Sometimes, flowers of a transitional type from male to hermaphrodite are found in the inflorescences. The inflorescences are small and compact in structure.
• Cluster and berry: The cluster is small, cylindrical, of medium density, and often has one wing. The berries are small, dark blue (larger in size than those of the rootstock 5BB). The seeds are small, oval, numbering 3-4 per single berry.
• Annual shoot: The green shoot is glabrous, with a weak luster, covered with a waxy coating, and has a green coloration with a wine-red tint. The mature annual shoot is reddish-brown, light-colored, and of medium thickness. The internodes are of medium length (10-14 cm). The shoots are rounded with a uniform thickness along their entire length, and the dorsiventrality is weakly expressed. The nodes are slightly thickened, with a violet tint, and weakly prominent. A characteristic varietal feature of the rootstock Riparia × Rupestris 101-14 is the easy separation of the bark in the form of long, thin pericyclic shreds (strips). The wood is dense and well-developed, and the pith is small (the ratio of the pith to the total diameter of the shoot is 0.3-0.4%).

Features of Agricultural Practices in Nursery Management

The rootstock variety Riparia × Rupestris 101-14 is distinguished by an increased capacity for lateral shoot formation (higher than in Riparia Gloire and Berlandieri × Rupestris 5BB), which requires the timely execution of green operations—suckering and lateral shoot removal. The most suitable supports in the mother vineyards are vertical four-wire or low horizontal trellises. The variety Riparia × Rupestris 101-14 demonstrates high productivity: under non-irrigated conditions in Moldavia, the yield is 100 thousand or more half-meter cuttings per 1 hectare; in Eastern Georgia, it is about 50 thousand meters of canes; and in Western Georgia, it is 46 thousand meters of shoots suitable for grafting. The cuttings of the rootstock Riparia × Rupestris 101-14 are characterized by good quality, high callus-forming capacity, and rooting ability—according to the data of the Ukrainian Research Institute of Viticulture and Winemaking named after V. E. Tairov, the survival rate is 85-96%. The average yield of first-grade saplings in the nursery field is 42-45%, reaching up to 60-62% in advanced enterprises.