The Effect of Potassium Fertilizer on Must and Wine Potassium Levels of Shiraz Grapevines

Shiraz grapevines in a cool, dryland vineyard (Eden Valley) and a hot, irrigated vineyard (Waikerie) were fertilized with potash for four years. Soil and petiole nutrient contents were monitored, and must and wine compositions from the treatments were investigated. In the hot vineyard, the use of KCl fertilizer increased petiole K, Cl, and Na concentrations; in the cool vineyard, no change occurred. Wine K + content was increased in cool vineyard wines by fertilization with KCl. The lack of a relationship between soil K and grape K concentrations is discussed.