Schwarzmann

Origin History and Economic Importance

The Schwarzmann grapevine rootstock is a natural hybrid selected in the first quarter of the 20th century in Bisenz (Moravia). Official admission for cultivation and registration in the Italian National Register of Vine Varieties (code 605) took place on March 26, 1971 (decree published in the Official Gazette G.U. No. 101 on April 23, 1971). Within clonal selection programs in Italy, three official clones of this variety have been registered: I - ISMA 607 (Agricultural Institute of San Michele all'Adige, 2004), I - VCR 122 (Vivai Cooperativi Rauscedo, 2005), and I - ISV CONEGLIANO 1 (CRA-VIT Viticulture Research Center, 2006).

According to the classic ampelographic studies by I. Cosmo, A. Comuzzi, and M. Polsinelli (1958), the morphological profile of the Schwarzmann rootstock variety exhibits a noticeable predominance of Vitis rupestris characteristics. In terms of cultural and agronomic traits, this rootstock closely resembles the well-known 101-14 rootstock variety, although it differs by having slightly higher vigor. Regarding phenological stages, the Schwarzmann rootstock is characterized by somewhat early budbreak and flowering, while leaf fall occurs at an intermediate time.

Morphological Description of the Schwarzmann Rootstock Variety

• Young Shoot (Shoot Tip at Flowering): Medium-sized, bristly (setose), and greenish-bronze in color.
• Apical Leaves (1st to 3rd): Unfolded, small, fairly velvety along the veins on the lower surface; greenish-bronze in color, with a very open, slightly brace-shaped petiolar sinus.
• Young Leaves (4th to 6th): Unfolded, entire, wider than long (resembling adult leaves in shape); lower surface bristly along the veins; light green in color; petiolar sinus slightly brace-shaped, reddish veins, and a petiole bristly along the groove.
• Shoot Axis (Stem): Slightly curved, glabrous, brownish-violet, and glossy on one side.
• Herbaceous Shoot: Circular in cross-section, glabrous, smooth, with nodes and internodes reddish-violet on one side.
• Tendrils: Intermittent, bifid and trifid, glabrous, with a pinkish tint.
• Flower: Functionally male.
• Mature Leaf: Medium-sized, slightly reniform, almost entire (or with a slight hint of three lobes). The petiolar sinus is a very open V-shape, slightly brace-shaped (with the central area where the petiole attaches being hollowed). The angle at the apex of the terminal lobe is acute. The leaf blade is trough-shaped and smooth; the upper surface is light green, glossy, and glabrous; the lower surface is light green and bristly along the veins. The veins are red at the base, depressed on the upper side, and prominent and green on the lower side. Teeth are pronounced, acute, fairly regular, and mucronate.
• Petiole: Medium to short in length, glabrous, pinkish on one side.
• Mature Woody Cane: Medium in length and thickness, sparsely branched, circular or slightly elliptical in cross-section; surface striated and glabrous. Color is reddish shaded with violet due to pruinose bloom, featuring grayish spots. Nodes are moderately prominent, internodes are of medium length (13–14 cm), and buds are conical and medium-sized.

Nursery Cultivation Characteristics

Mother vines produce shoots of medium length and sturdiness with weak lateral shoot growth (sparsely branched) and medium internode length (13–14 cm), which facilitates cane harvesting. In Italian nursery production, the Schwarzmann grapevine rootstock is propagated in small volumes to maintain true-to-type planting material of the highest certification categories (specifically, 98 own-rooted vines of the "Initial" category were produced in 2018, and 294 vines of the "Basic" category in 2022).

* VINEYARD Note: According to other sources, it is the result of a controlled Riparia × Rupestris cross made by the breeder Schwarzmann in 1891.