Evaluating the Impacts of Viticultural and Environmental Factors on Rotundone in Noiret Grapes

Download or read book Evaluating the Impacts of Viticultural and Environmental Factors on Rotundone in Noiret Grapes written by Andrew David Harner and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The grape-derived sesquiterpenoid rotundone is responsible for the black pepper aroma of several wine grape varieties, including the interspecific hybrid Noiret. Numerous studies have evaluated the effects of major climatic variables, including both temperature and solar radiation, on the accumulation of rotundone in wine grapes. However, only a few studies have assessed the effects of common viticultural management practices, and no studies have assessed both climatic and viticultural influence together in a single study to fully investigate which variables have the strongest influence on rotundone concentrations. Over the 2016 and 2017 seasons, we evaluated the influence of 21 different viticultural, meso- and microclimatic variables on the concentrations of rotundone in Noiret wine grapes at 7 Pennsylvania and New York vineyards with distinct environmental conditions. Vineyard-scale post-veraison temperatures and solar radiation had robust and positive correlations with rotundone concentrations measured at harvest. At the level of the fruiting zone, rotundone concentrations correlated negatively with post-veraison temperatures below 15 degrees Celsius, above 30 degrees Celsius, and pre-veraison fruit sun exposure. Rotundone concentrations were also strongly correlated to several grapevine tissue nutrients, including calcium, potassium, and magnesium. A four-variable model was constructed using multiple linear regression analysis of the vineyard-scale data. This model can be used by growers to identify vineyards with potential for producing peppery wines, as well as assist growers with manipulating rotundone concentrations via implementation of canopy management practices to achieve wines with the desired levels of rotundone and related pepperiness.