About PIWI Grapes
PIWI Grape Varieties
US Hybrid (PIWI) Grapes
The three main contributors to grapevine research in the United States are Cornell University in New York, the University of Minnesota and Davis University in California.
Aromella (Ravat 34 and Traminette) and Valvin Muscat (Muscat du Moulin (Coderc 603) x Muscat Ottonel)
University of Minnesota
Cold weather research. The variety Marquette has Ravat Noir in its lineage and Itasca and Clarion have Seyval Blanc.
University of California, Davis
Mostly vinifera but has done work on Pierce's disease and curated a large collection of grapevine varieties. Aside from getting Fay Rouge, which is mostly vinifera but includes Ravat Noir as a grandparent and includes Munson and labrusca in its genetic history.
Pierce’s disease resistance
Vitis arizonica - Camminare noir, Paseante Noir, Caminante blanc, Ambulo blanc and Errante noir
V. arizonica has single dominant gene for resistance to PD and it’s homozygous
Grapes surviving the cold and spawning an industry
No single grape released by the University of Minnesota has had the transformational impact Honeycrisp had on the apple industry, but UMN cold-hardy grapes have a different claim to fame: laying the foundation for an Upper Midwest wine industry. In the 1980s, there were two wineries in Minnesota.