Vierul-2
| Variety Passport | |
| Country of origin: | USSR (Moldavian SSR) |
| Breeder: | Moldavian NIIViW |
| Variety number VIVC: | 16471 |
| Prime name: | Vierul 2 |
| Breeding number: | 37-70 |
| Year of obtaining / registration: | Year of crossing 1965 |
| Pedigree given by breeder: | Riparia × Rupestris 101-14 × Berlandieri × Riparia Teleki 8B |
| Rootstock type: | Phylloxera-resistant, Lime-tolerant |
| Data Sources: | Vitis International Variety Catalogue (VIVC), Ампелография СССР (1946–1970) |
| Agrobiology | |
| Vigor: | medium |
| Flower type: | female |
| Shoot ripening: | 82-95% |
| Active lime tolerance: | 16% |
| Resistance to fungal diseases: | very high |
| Graft compatibility with Vitis vinifera: | high |
| Recommended soil types: | Carbonate soils; the variety is unpretentious to soil conditions and can grow on steep slopes |
| Ampelographic overview |
Origin History and Economic Significance
The rootstock grape variety Vierul-2 was bred in 1965 at the Moldavian Research Institute of Viticulture and Winemaking (NIIViW) by crossing the combinations Riparia × Rupestris 101-14 and Berlandieri × Riparia Teleki 8B. The authors of the variety are G. M. Karadzhi, I. P. Gavrilov, and O. S. Rebeza. The variety is recommended for use as a rootstock in all viticultural zones of the Moldavian SSR with carbonate soils to replace the Berlandieri × Riparia Kober 5BB rootstock.
Vierul-2 grafts well with many European grape varieties. It ensures a high yield of first-rate saplings in the nursery (shkolka), as well as stable and consistent yields in grafted vineyards. Compared to the Kober 5BB rootstock, this variety accelerates the ripening of grapes on scions by an average of 5–7 days. With equal growth vigor to Berlandieri × Riparia Kober 5BB, Vierul-2 surpasses it in terms of early shoot maturation and the yield of high-quality cuttings.
Ampelographic Description of the Vierul-2 Variety
- Young shoot (tip): The tip of the young shoot is light green, without pubescence. Young shoots are characterized by an intense wine-violet coloration. The first young leaves are yellow-green, shiny, with a faint golden tint.
- Formed leaf: The leaves are large or medium-sized, oval, three-lobed, and almost entire. The leaf blade is slightly trough-shaped (infolded), with a smooth, light green, matte upper surface. Pubescence on the lower surface of the leaf is completely absent.
- Sinuses and petiolar sinus: Upper and lower sinuses are absent or barely marked as an incoming angle. The petiolar sinus is wide open and shallow. The veins at the very base of the leaf blade are wine-violet.
- Teeth: The teeth at the ends of the lobes are large, narrow-triangular, with distinct pointed tips. The teeth along the margin of the leaf blade are dome-shaped with a wide base.
- Flower: Functionally female flower type.
- Cluster and berry: The cluster is small, cylindrical-conical, and loose. The berry is very small, round, dark violet during ripening, and acquires a characteristic blue-black shade when fully ripe. The seeds are small, round, and dark brown.
Features of Agricultural Technology of the Vierul-2 Grape Rootstock
Vierul-2 is unpretentious to soil conditions and is suitable for cultivation on steep slopes. It does not suffer from chlorosis when the active lime content in the soil is up to 16% according to Galet. The maturation of annual shoots begins in the second half of August, and by the end of the growing season, the degree of their wood maturation reaches 82–95%. With a spacing area in mother plantations of 2.6 × 1.7 m, the average yield of cuttings suitable for grafting is 90 thousand pieces per hectare of the Vierul-2 variety.