Winegrowers Supplies - Vine variety information
Glenora - SeedlessMother: Ontario
Father: Russian Seedless
Note: Russian Seedless is a synonym for Black Kishmish but has been used, incorrectly, as a synonym for Black Monukka. Russian Seedless was reported to be a parent of both Glenora and Suffolk Red; in both of the original publications (Einset, 1973; Pool et al., 1977) the parent was described as "probably" being Black Monukka. DNA analysis by Cornell has now shown that only Black Kishmish, not Black Monukka, produced fingerprints consistent with parentage of Glenora and Suffolk Red.
Year of breeding: selected in 1952, released in 1976; known originally as NY 35814.
A breeding programme to produce seedless grapes was begun by the New York State Agricultural Experiment Station in 1919. A major goal of the programme was to combine the seedless character that is derived from winter cold tender, disease susceptible grapes of Mediterranean origin with native American grape varieties in order to produce seedless varieties which are adapted to New York growing conditions.
Between then and 1976, four white (Interlaken, Himrod, Romulus, and Lakemont) and one red (Suffolk Red) seedless varieties were released. They all share the attribute of having as one parent a Mediterranean grape variety. This inevitably results in some reduction in the vines ability to survive winter cold. The above named cultivars are classified as low in winter hardiness for harsh USA winter conditions where below -25 °C can occur.
There has been considerable demand for a blue-black seedless grape similar to the red and white ones listed above. Glenora meets this demand. Glenora vines are productive and appear to be resistant to phylloxera, so that they do not need to be grafted to a resistant rootstock. The flowers are perfect and the stamens upright. The clusters are large and the berries medium. It is relatively disease-resistant. The skin is blue-black and adherent but not hard. The flesh is melting and the flavour delicate, sweet, refreshing, juicy, and not noticeably labrusca in character.
Glenora fruits respond very favorably to gibberellin treatment. In common with the previously released seedless varieties, Glenora is not fully winter hardy. In test winters, when the temperature has dropped below -23 °C, there has been bud injury (up to 70%) and trunk injury to the vines. However, in most seasons Glenora produces a full crop at Geneva. Double trunking and trunk renewal are recommended.