Utilizing Pruning and Leaf Removal to Ripen Grapes and Encourage Cold Tolerance in North Dakota
Abstract
Experiments were conducted at North Dakota vineyards in 2011 and 2012. Pruning limited vines to a specific number of primary buds while leaf removal exposed ripening grape clusters to increased sunlight. Variables included length of growth prior to dormant pruning, weight of growth, rate of ripening, total weight of harvested grapes, weight per grape cluster, berry weight, number of clusters per vine, soluble solid concentration (°Brix), titratable acidity (TA), and pH. Data were analyzed as a CRD with a factorial arrangement. Analysis showed varied significance with pruning and shade leaf removal interacting with specific cultivar traits to influence growth, grape yield, and grape quality. Impact on yield was minimal, treatment impacts on grape quality showed potential for use of shade leaf removal as means of decreasing titratable acidity levels in harvested grapes. Research supports the use of pruning and shade leaf removal treatments to influence grape production.