Effects on Must and Wine Composition, Rates of Fermentation, and Wine Quality of Nitrogen Fertilization of Vitis Vinifera Var. Thompson Seedless Grapevines

Abstract

Thompson Seedless vines were treated for three years with various levels of nitrogen fertilizer. The vineyard had not been fertilized for over seven years preceding. The clarified grape juice was analyzed for various components. The rates of fermentation, concentration of esters, and wine quality were dependent on the level of nitrogen fertilization. Fertilization with 112 kg N/ha (100 lb-N/acre) was sufficient for the juice to have a rapid fermentation and the wine to be of good quality. Juice from vines not fertilized fermented more slowly, resulted in wines of poorer quality, and was deficient in a number of chemical components.