Horticultural performance and juice quality of cold-climate grapes in Vermont, USA

Abstract

Grape and wine production is a relatively new agricultural enterprise in Vermont with a history of only two decades. Winegrape cultivar performance has been evaluated at the University of Vermont Horticulture Research and Education Center in South Burlington, VT (USDA hardiness zone 5a) since 2007. Six winegrape cultivars were assessed in a randomized complete block design of six blocks with four vine plots of each cultivar per block: ‘Corot Noir’, ‘Frontenac’, ‘La Crescent’, ‘Marquette’, ‘Prairie Star’, and ‘St. Croix’. Vines were trained in a bilateral cordon system at a density of 1,793 vines ha-1. Assessed horticultural parameters included: vine pruning weight; primary winter bud survival, shoot production from retained nodes; crop yield; and juice quality parameters. ‘Frontenac’, ‘La Crescent’, ‘Marquette’, ‘Prairie Star’, and ‘St. Croix’ rated well for measurements of cold hardiness and vine vigor. All cultivars in the trial had economically acceptable mean annual crop yield, except ‘Prairie Star’ which had lower mean annual crop yield than most other cultivars. ‘Corot Noir’ had among the highest crop yield, but suffered from greater winter damage and is likely marginal for cold hardiness in many season at the trial site. ‘Frontenac’, ‘La Crescent’, and ‘Marquette’ produced juice with higher titratable acidity (TA) and soluble solids than other cultivars, and ‘Corot Noir’ and ‘St. Croix’ juices ranked lower for those variables. Of the evaluated cultivars, ‘Marquette’ and ‘La Crescent’ exhibit the best juice quality, crop yield, and cold hardiness characteristics and are especially suited for commercial production in Vermont.