Evaluation of cold-hardy grape cultivars for North Dakota and the North Dakota State University germplasm enhancement project
The development of cold hardy, Vitis riparia-based grape cultivars in the 1990s started a new industry of small vineyards and wineries in the New England, Upper Midwest and northern Plains regions of the United States. A cultivar evaluation study was conducted over a seven-year period to identify cold-hardy hybrid grapes adapted to the harsh environmental conditions of North Dakota. Weather data indicated that grape cultivars must be able to ripen their fruit with as little as 1184 accumulated growing degree day units and with a growing season of only 132 days as observed in 2010. Our trial indicated that three cultivars, 'King of the North', ES 12-6-18, and 'Valiant', were adapted to North Dakota conditions, even though yields were reduced in 2010. Unfortunately, the wines that can be produced from two of the three cultivars, 'Valiant' and ES 12-6-18, fall short of the goals of most winemakers and their potential customers. The high titratable acidity levels of 'King of the North' will greatly limit winemaking styles. 'Marquette', MN1200, and ES 5-4-71 did not have reliable hardiness as each yielded less than an average 770 kg ha-1 over the seven-year testing period. The highest yielding white winegrape, when averaged over seven years, was 'Alpenglow' with a yield less than half from the top three yielding cultivars. Therefore, research at North Dakota State University (NDSU) has focused on the development of hardier V. riparia-based cold-hardy winegrape cultivars that will survive the harsh North Dakota environment and consistently produce fruit and high quality wine.
Hatterman-Valenti, H.M., Auwarter, C.P. and Stenger, J.E. (2016). Evaluation of cold-hardy grape cultivars for North Dakota and the North Dakota State University germplasm enhancement project. Acta Hortic. 1115, 13-22
winegrapes, viticulture, phenology, low temperature, cold hardiness, Vitis riparia