Fecha de publicación:
30/09/2016
Fuente: ecent issues American Journal Of Enology and Viticulture
The seasonal timing of biomass and nutrient distribution among different vine organs was determined over two growing seasons in four-year-old Pinot noir grapevines grown in field microplots. Vines were fertilized in spring, and biomass and nutrient contents of nine separate vine parts were measured at six phenological stages (budbreak, bloom, veraison, harvest, leaf fall, and dormancy) each year. The uptake and distribution of four micronutrients—boron (B), zinc (Zn), Manganese (Mn), and copper (Cu)—was determined for the first time in field-grown grapevines. Whole-vine nitrogen (N) uptake was maximal early in the season, with most N uptake occurring before bloom. Uptake of phosphorus (P) and sulfur (S) was also early compared to other nutrients, with similar quantities of these elements taken up between budbreak and bloom and between bloom and veraison. All other macronutrients—potassium (K), calcium (Ca), and magnesium (Mg)—and micronutrients (B, Zn, Mn, Cu) had peak uptake between bloom and veraison. Remobilization of nutrients from permanent vine structures helped supply early season canopy needs for N, K, and S. More N was remobilized from reserves and this lasted until veraison, supplying ~35% of the canopy N between budbreak and veraison. Remobilization of K and S occurred only until bloom and contributed ~30% of the canopy increase in these elements up to that time. The small root fraction was the main source of remobilized nutrients for N, K, and S. A net annual gain of nutrients in the permanent vine parts occurred for P, K, Ca, Mg, Zn, and Cu. The quantities of each nutrient required by young Pinot noir grapevines carrying a typical crop yield for the region are presented and discussed.