N, P, and K Supply to Pinot noir Grapevines: Impact on Berry Phenolics and Free Amino Acids

摘要: Understanding the direct role that macronutrient supply (N, P, and K) has on berry chemistry was evaluated in Pinot noir grapevines grown sand culture. Self-rooted vines were for three years with either full nutrition (Control) or reduced levels of N, K while holding all other nutrients constant. Vines managed to minimize differences vine water status (altering irrigation achieve similar daily soil moisture content) fruit cluster solar exposure leaf pulling irradiance) due varying nutrient so indirect effects could be largely eliminated. Berry second third after different treatments imposed. Results showed low but not P K, altered free amino acid (FAA) phenolic profiles. Low N FAA yeast assimilable nitrogen (YAN) both by up 70% certain FAAs more than others, thus changing profile. The concentration sugars, anthocyanins, flavonol-glycosides increased during season, increase sugars anthocyanins attributed decline size year. Condensed tannins total acids across years, independent changes size. indicated YAN greatest degree, anthocyanin enhancement did occur until yield also reduced. Increased concentrations berries occurred response reductions