Couderc 1616

History of Origin and Economic Significance

The grape rootstock Solonis × Riparia 1616 is an interspecific hybrid bred in France in 1881 by the well-known scientist and breeder Georges Couderc. The variety was obtained by crossing the salt-tolerant hybrid Solonis with the purebred American species Vitis riparia. In the commercial viticulture of the USSR, the rootstock variety Solonis × Riparia 1616 was used locally, mainly in the south of Ukraine, the Azov region, and certain areas of the Lower Don, where saline soil types are present. The primary advantage possessed by the grape rootstock Solonis × Riparia 1616 lies in its outstanding salt tolerance inherited from the parental Solonis form, which allows for successful grapevine cultivation on plots unsuitable for other American rootstocks. The variety Solonis × Riparia 1616 is characterized by high affinitative compatibility with many European grape varieties of Vitis vinifera, providing grafted plants with moderate, balanced vegetative development and regular production.

Soil Recommendations and Resistance to Environmental Factors

Based on specialized ampelographic research, the rootstock Solonis × Riparia 1616 is strictly recommended for cold, deep, loose, or loamy soils of medium mechanical composition. Due to the resistance of the parental line to excessive moisture, this rootstock variety perfectly tolerates a high water table and temporary waterlogging of the plot. The drought resistance indicators of the hybrid are medium. The carbonate resistance is low: the rootstock Solonis × Riparia 1616 is capable of withstanding active calcium content in the soil solution within up to 11% according to the Galet scale, and on lands richer in limestone, the bushes are rapidly affected by chlorosis. The root system of the variety Solonis × Riparia 1616 possesses high frost resistance, reliably protecting the underground part of the vine from winter damage in climatic zones with deep soil freezing.

Morphological Description of the Rootstock Variety Solonis × Riparia 1616

The morphological characters and botanical description of the variety Solonis × Riparia 1616 allow for accurate field identification in mother vineyards:

• Young shoot (tip): The tip of the young shoot is half-open, green with a weak anthocyanin (wine-red) tint along the margins, and covered with soft cobwebby and bristly pubescence. Young leaves are three-lobed, folded, with a light green surface.
• Mature leaf: The leaves are of medium size, round or widely cuneate in shape, three-lobed with small, weakly outlined lateral sinuses. The leaf blade is flat, smooth on the upper side, with slightly turned-down margins. On the lower side of the blade of the rootstock Solonis × Riparia 1616, a noticeable bristly pubescence is present, concentrated mainly on the branching of the veins of the first and second orders. The petiole sinus is open, lyre-shaped or U-shaped with a flat base.
• Teeth: Sharp, saw-toothed, relatively large, with a widened base and well-expressed light points at the apexes.
• Petiole: Practically equal in length to the median vein of the leaf or slightly shorter, colored a pale green with a light pinkish tint on the sunny side, and bears weak bristly pubescence.
• Flower: Functionally female flower type. Inflorescences are small, compact, and form in moderate numbers.
• Cluster and berry: The clusters are very small, cylindrical in shape, and dense. The berries are small, rounded, black with a thick waxy coating, and contain small seeds.
• Annual shoot: The cane is characterized by medium thickness and moderate vigor of the bush. The coloration of the bark of the annual shoot is light, grayish-brown or yellowish-brown with darker nodes. The cross-section of the shoot is round, and the internodes have a medium length (11-13 cm). The surface of the shoot is smooth, the nodes are moderately prominent, and the eyes (buds) are small and round-conical.

Features of Agricultural Practices in Nursery Management

The rootstock variety Solonis × Riparia 1616 is distinguished by a medium capacity for lateral shoot formation, which minimizes total manual labor costs for conducting shoot removal in cane mother vineyards. The ripening of the shoots by the end of the vegetative period is stably high and reaches 80-85% of the total growth, ensuring the formation of high-quality wood. The capacity of cuttings to root in commercial nurseries is rated as medium—the rooting ability is slightly inferior to pure Riparia × Rupestris hybrids, which requires strict adherence to the temperature regime during callusing and the mandatory use of growth stimulators. The grape rootstock Solonis × Riparia 1616 possesses practically complete immunity to the root form of phylloxera and high resistance to downy mildew; however, it is heavily damaged by the foliar (gall) form of phylloxera, which dictates the necessity of timely insecticide treatments in mother vineyards.