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December 2017 WINES&VINES 57 PRACTICAL WINERY & VINEYARD GRAPEGROWING RELATIVE INCREASE OF VINE BIOMASS AND RELATIVE NUTRIENT UPTAKE Growth period a Percent of Total Increase by Fruit Maturity Dry Mass Nitrogen Phosphorus Potassium Calcium Magnesium Sulfur Boron Zinc Manganese Copper Bud break to bloom 5 65 36 20 14 18 42 39 17 30 23 Bloom to véraison 60 32 43 66 51 57 51 55 57 52 46 Véraison to harvest 35 3 21 14 35 25 7 6 26 18 31 Percentages averaged between the first three growth periods in four-year-old Pinot Noir grapevines grown in micro-plots over two years. a Vines were destructively harvested at each growth stage, and the increase in biomass or nutrient content was calculated by subtracting the mean value from the previous growth stage from each of the replicates at a later growth stage (n=20). The percent of the total increase at fruit maturity was then calculated for each growth period. fore, phosphorus was not remobilized from roots and trunks to help supply canopy phos- phorus demand in the young vines. This finding differs from the previous trial in older Pinot Noir grapevines, where as much as 50% of canopy phosphorus needs came from stored reserves. 11 Potassium: Potassium uptake was maximal between bloom and véraison, accounting for 66% of the total potassium uptake by fruit maturity (see "Changes in Potassium Content" on page 55). Roughly similar amounts of potassium uptake (14%-20%) occurred be- tween bud break and bloom and between véraison and harvest. Remobilization of stored potassium (mostly from the smallest roots) helped sup- ply early season canopy potassium needs up until bloom, which averaged 30% of canopy needs by bloom over both years. Similar small quantities of potassium were shown to be remobilized in other studies, but this oc- curred later in the growing season. 9,11 The large accumulation of potassium in fruit clusters is well known. Calcium, magnesium and sulfur: Calcium uptake was greatest between bloom and vé- raison, followed by the period from véraison to harvest and least from bud break to bloom (see table "Relative Increase of Vine Biomass and Relative Nutrient Uptake"). Clusters ac- cumulated very little calcium in either year. Total vine magnesium content increased from bud break to bloom, from bloom to véraison and from véraison to harvest, then declined from harvest to leaf fall. The bulk of magne- sium uptake occurred between bloom and véraison (see table). Magnesium was not re- mobilized in the young vines to support can- opy magnesium needs. Total vine sulfur content increased be- tween bud break and bloom and again from bloom to véraison, then declined from harvest to leaf fall. Uptake of sulfur was similar from bud break to bloom and from bloom to vérai- son, with each time period accounting for more than 40% of sulfur uptake by harvest. Sulfur was remobilized from permanent vine parts to help supply canopy needs between bud break and bloom. Boron: Uptake of boron was maximal be- tween bloom and véraison (55%), and less uptake occurred between bud break and bloom (39%), and lesser still (6%) between ONLINEMARKETINGSYSTEM Wines Vines Analytics Visit winesandvines.com/OMS or call 866.453.9701 to set-up your free demo. Reach Thousands of Winery Decision Makers The Wines & Vines Online Marketing System is designed to help your business: • Increase sales • Generate winery leads • Manage clients and sales territories • Improve marketing effectiveness