Solbrio

Figure 1. Solbrio leaf
Photo by Matthew Fidelibus

Figure 2. Solbrio cluster
Photo by Matthew Fidelibus

The origin of Solbrio was documented by Ledbetter. Solbrio originated from a planned cross of Vitis vinifera L. selections designed by David Ramming, USDA-ARS. Both parents used in the 2004 cross were seedless, and seedlings were developed following the embryo rescue technique. Seedlings from the cross were outplanted in 2005 and began fruiting in 2006. One seedling was selected and patented as Solbrio on 22 January 2019.

Ledbetter described Solbrio as moderately vigorous, with a semi-drooping habit. In the San Joaquin Valley of California, Solbrio has an earlier budbreak than many other common table grape varieties. Shoots arising from spurs average 2 clusters per shoot, and average 100 clusters per vine, before thinning. Clusters are medium in size, conical in shape, and slightly loose. Vines thinned to 55 to 60 clusters per vine averaged 50 lbs of fruit/vine. Gibberellic acid at bloom and berry set were found to be detrimental and are not recommended. Similarly, trunk girdling did not improve berry size or fruit quality.

Solbrio has fruitful basal buds and can be cordon-trained (quadrilateral cordons) and spur pruned. Modern table grape vineyards in California typically use open-gable trellis systems, which are Y-shaped trellises typically spanning 10 feet and supporting three foliage wires on each arm.

Solbrio clusters typically average 350 g, with elliptical-shaped berries that average approximately 7.3 g. Berry skin is medium thickness and achieves full color without the use of plant growth regulators. At harvest, soluble solids are approximately 19 Brix, and titratable acidity is 0.39%, resulting in a relatively high Brix:acid ratio. Texture is crunchy, and seed traces are few and small. Postharvest shatter is said to be low.

Ledbetter, C.A. ‘Solbrio’ table grape. HortScience 54(10):1864-1865.