Grapevine cv. 'Sugratwentyone'

This invention relates to the discovery and asexual propagation of a new variety of grapevine, cv. 'Sugratwentyone'. The new variety was first hybridized by David W. Cain in Wasco, Kern County, Calif., the variety being originated by controlled bybridization and subsequent ovule culture of normally abortive seeds. The new 'Sugratwentyone' variety is characterized by producing large clusters of red, naturally large seedless berries that are uniform, crisp and round. A new and distinct grapevine variety characterized by naturally large, red, seedless berries that are crisp, round and uniform. Berries of the new 'Sugratwentyone' variety are thin-skinned and are strongly attached to large, slightly compact clusters.