Vineyard Nutrition: Reevaluation of Sampling Protocols
Nataliya Shcherbatyuk, Pierre Davadant, and
Markus Keller*
*WSU, Prosser IAREC, 24106 N. Bunn Rd., Prosser, WA, 99350
(mkeller@wsu.edu)
Vineyard nutrient management is crucial to reach production-specific quality standards, yet timely nutrient status evaluation remains challenging. The existing sampling protocol of collecting vine tissue (leaves and/or petioles) at bloom or veraison is time-consuming and does not provide spatial resolution for vineyards. Moreover, fertilizers are often applied based on historic nutrient data. The main goals of this project are to 1) optimize existing tissue-sampling protocols; and 2) determine the amount of nutrients removed at the end of the growing season. Updated protocols will support development of non-destructive tools for real-time monitoring of vineyard nutrient status. Soil and tissue sampling started in 2020, and field trials were established in 2021, in commercial vineyard blocks in Washington, with three rates of K applied in Chardonnay, three rates of N applied in Syrah and Sauvignon blanc, and two rates of N applied in Concord. Dormant canes and trunks; whole shoots at the five-to-six leaf stage; leaves (blades and petioles) at bloom and veraison; berries at lag phase and harvest; whole clusters at harvest; and whole leaves at leaf fall were collected from each block. Results showed no significant differences in yield components of harvest fruit and in nutrient levels of shoots, or in leaf blades collected at bloom or veraison (samples are still being processed). Blade and petiole nutrient concentrations were not well correlated with higher N concentrations and lower K concentrations in blades than petioles. There were positive correlations between N, P, and K concentrations in cane internodes and trunks in Chardonnay, and between P and K concentrations in dormant tissues and leaf blades. Fruit harvest and leaf fall removed significant amounts of nutrients per hectare, depending on variety and crop yield. Lost nutrients must be replaced through fertilizer addition to sustain vineyard productivity.
Funding Support: USDA-NIFA-SCRI, WA State Grape and Wine Research Program, WA State Concord Grape Research Council
