Submitted to: American Journal of Enology and Viticulture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/15/2012
Publication Date: 3/1/2013
Citation: Schreiner, R.P., Lee, J., Skinkis, P.A. 2013. N, P, and K supply to Pinot noir grapevines:Impact on vine nutrient status, growth, physiology, and yield. American Journal of Enology and Viticulture. 64(1):26-38.
Interpretive Summary: The response of Pinot noir grapevines to varying nutrient (nitrogen, phosphorus, and potassium) supply was investigated in a sand culture vineyard using a pot-in-pot system. Results obtained provided the basis to refine leaf blade nitrogen critical values for Pinot noir produced in the region. Critical values for phosphorus and potassium status could not be as clearly identified here. Leaf blade nitrogen concentrations of 25 g kg-1 (or 2.5%) at bloom and 1.8 g kg-1 (or 1.8%) at véraison were required to maintain yields and provide adequate yeast assimilable nitrogen concentrations in berries. Leaf blade P values of 2.3 g P kg-1 (or 0.23%) at bloom appear to be required to provide juice P concentrations of approximately 100 ppm. Leaf blades were better indicators than petioles for N and P status, while petioles were a better indicator for K status. Visual symptoms of low N and low P levels in Pinot noir leaves, and instantaneous vine growth and other physiological responses were not reliable indicators of potential deficiencies of N or P in the field.
Technical Abstract: Pinot noir grapevines (self-rooted, Pommard clone) were grown in a pot-in-pot sand culture vineyard to examine the impact of low N, P, and K supply on vine growth and physiology. Four-year-old vines were given either full nutrition (Control) or reduced levels of each N, P, and K supplied at 50%, 20%, or 10% of the Control rate with all other nutrients held constant over three years (2006-2008). Vine growth, nutrient status, photosynthetic parameters, yield, and berry quality were monitored. The N, P, and K status of vines was reduced by each of the intended treatments, although N and P concentrations in leaf blades and petioles were reduced earlier and to a greater extent than was K. Low N treatments reduced dormant season cane weights in all years, shoot lengths and leaf area in 2008, and fruit yield in 2008. Yield reduction under low N supply in 2008 was primarily a result of reduced berry size. Low N also reduced single leaf photosynthesis and quantum efficiency of photosystem II in 2008, while low P and K did not. Juice YAN (yeast assimilable nitrogen) levels were greatly reduced by low N supply in 2007 and 2008, although YAN was lower in 2007 across all treatments. Low P and low K supply did not alter growth or yield. Low P supply reduced juice P concentrations, but low K supply did not alter juice K. Reduced yield, growth, and juice YAN levels in low N treatments provides a framework to refine leaf blade and petiole N standards for Pinot noir grown in the region, but limiting levels of P and K were not as clearly defined here.