Andrej Svyantek, John Stenger, Bulent Kose, Collin Auwarter, and Harlene Hatterman- Valenti*
*NDSU, PO Box 6050, Dept. 7670, Plant Sciences, past instructor, ND, 58108 (h.hatterman.valenti@ndsu.edu)

Grapevines for wine production are a new agricultural crop for North Dakota, with commercial cultivation initiated in the 21st century. The >20-year history of winegrape production coincides with the advent of state laws allowing legal production of local wine and developments in breeding material leading to newly generated cold-har­dy grapevine genotypes. In response to the lack of existing knowledge concerning genotype adaptability, at the dawn of North Dakota grapevine production, a variety trial was planted in eastern North Dakota. With consistent yield a critical need under North Dakota’s unrelenting winter conditions, cumulative yield data (2007 to 2019) was examined using analytical stability metrics and multivariate approaches to assess genotype × environment interactions and make cultivar recommendations for the re­gion. The most stable genotypes according to multiple stability metrics were MN1200 and Marquette; however, their yield stability stems from consistently low production levels rather than commercially acceptable yields. Marquette, MN1200, E.S.5-4-71 and La Crescent produced the lowest mean yields. King of the North and Valiant were the highest-performing genotypes according to the grand mean; they were individually ranked as most stable genotypes according to one stability metric each (King of the North for CV% and Valiant for superiority measure [Pi]). The stability metrics most closely associated with top-yielding lines included CV%, bi, Pi, Si1, and Si2. High-per­forming lines ranked poorly based on Sd, S2di, R2, ri2, Dji, and Wi. New techniques for differentiating genotypes, such as stability analysis, may become increasingly perti­nent under changing climate conditions and to anticipate performance of newly-de­veloped cultivars for their capacity for future planting into challenging landscapes.

Funding Support: ND Specialty Crop Block Grant