Resumen de A review of potassium nutrition in grapevines with special emphasis on berry accumulation
Daniel P. Schachtman, Michael Treeby, Mark R. Thomas, Bussakorn S. Mpelasoka
Potassium (K) is essential for vine growth and yield. Grape berries are a strong sink for K, particularly during ripening. Excess K levels in grape berries may have a negative impact on wine quality, mainly because it decreases free tartaric acid resulting in an increase in the pH of grape juice, must and wine. In Australia, high K status is common in most vineyards, which reflects the high K and high pH values of most Australian grape juice. This necessitates pH adjustment during the vinification process, and tartaric acid addition is a common practice in most Australian wineries. High K concentration may also lead to excessive loss of the additional tartaric acid by precipitation as potassium bitartrate and, as a consequence, pH adjustment becomes more difficult and expensive. Ensuring naturally low K levels in the berry will help reduce costs of input and waste management at the winery. Potential vineyard management options to manipulate berry K accumulation include selective use of rootstock/scion combination, canopy management and irrigation strategies. However, the impact of these practices on determining the optimum K concentration requires careful calibration of production parameters and the desirable grape juice and wine quality in relation to tissue K concentration. This paper reviews and discusses the possible functions of K in grape berries, translocation of K into the berry, and genetic and cultural factors that may affect the accumulation of K in the berry. This will help to identify the key research and management strategies needed for controlling K concentrations in grape berries.
Potassium (K) is essential for vine growth and yield. Grape berries are a strong sink for K, particularly during ripening. Excess K levels in grape berries may have a negative impact on wine quality, mainly because it decreases free tartaric acid resulting in an increase in the pH of grape juice, must and wine. In Australia, high K status is common in most vineyards, which reflects the high K and high pH values of most Australian grape juice. This necessitates pH adjustment during the vinification process, and tartaric acid addition is a common practice in most Australian wineries. High K concentration may also lead to excessive loss of the additional tartaric acid by precipitation as potassium bitartrate and, as a consequence, pH adjustment becomes more difficult and expensive. Ensuring naturally low K levels in the berry will help reduce costs of input and waste management at the winery. Potential vineyard management options to manipulate berry K accumulation include selective use of rootstock/scion combination, canopy management and irrigation strategies. However, the impact of these practices on determining the optimum K concentration requires careful calibration of production parameters and the desirable grape juice and wine quality in relation to tissue K concentration. This paper reviews and discusses the possible functions of K in grape berries, translocation of K into the berry, and genetic and cultural factors that may affect the accumulation of K in the berry. This will help to identify the key research and management strategies needed for controlling K concentrations in grape berries.
