The 2011 ASHS Annual Conference

Nutrient uptake and allocation patterns were determined in four year-old grapevines (‘Pinot noir’ clone 115 on 3309C rootstock) by destructively harvesting entire vines at major phenological stages over two years. In addition, half of the vines were irrigated less frequently between veraison and fruit harvest to determine if access to soil water at this time would influence nutrient uptake or berry nutrient levels (particularly YAN). Even though vine water use and water status were reduced in the dry treatment, irrigation had only minor effects on vine growth or nutrients. Total vine dry matter was reduced in one year by ~ 4% and whole-vine P content was reduced across both years by ~ 3% in the dry treatment. Yield, juice YAN, and other berry quality parameters were not altered by irrigation. Vine nutrient uptake of macro- and micro-elements was similar for both years, except for N which was taken up during the dormant period (after leaf senescence) in one year only. Although, the peak time of N uptake occurred between budbreak and bloom in both years. Peak uptake of P and B was similar between the time periods of budbreak to bloom and bloom to veraison, while peak uptake of K, Ca, Mg, S, Mn, Zn, and Cu occurred between bloom and veraison. Vines utilized stored reserves of N, K, and S from roots and trunks to help supply early season canopy demand. Roughly one-third of canopy demand for K and S was supplied from stored reserves between budbreak and bloom, while 30-43% of canopy N was supplied from reserves up until veraison. Young ‘Pinot noir’ vines carrying their first normal crop had a net uptake of 12 pounds of N per acre, ~25 pounds of K and Ca per acre, 3 pounds of P per acre, and 4 pounds of Mg per acre. The timing of nutrient uptake by young vines was generally consistent with previous findings in mature (24 year-old) ‘Pinot noir’ vines grown in the same region. However, young vines utilized proportionally less stored N, little or no stored P, and young vines began to replenish root and trunk reserves of macronutrients earlier in the growing season than older vines studied earlier.