There has been some clear progress on the potassium (K) fertility issue in symptomatic North Coast vineyards. These vineyards are typically on soils with K fixing clays (some also with high Mg), and often have “not responded” to earlier conventional applications of potassium sulfate. We have used high rates of potassium sulfate (81bs or greater of potassium sulfate per vine) and supplemental irrigation (2 to 4 times the standard rate) to decrease K fixation and increase the availability of K for root uptake. This has successfully increased vine K status and maintained high K status beyond veraison. The genetic approach to managing these soils also looks promising. For Chardonnay vines on low K soil, vine K status was significantly greater on 5C and St. George rootstocks than on four other root systems. Applications of K to these vines increased juice pH on some rootstocks and decreased the concentration of malate on all rootstocks.
/wp-content/uploads/2017/09/AFV-Header-Logo.png 0 0 AVF /wp-content/uploads/2017/09/AFV-Header-Logo.png AVF1993-11-22 16:00:162017-11-22 16:00:51Vineyard Management Strategies for Potassium Nutrition and Optimum Winegrape Quality