Growing & Winemaking

 

Probing Nutrient Needs of Pinot Noir Vines

December 2017
 
by R. Paul Schreiner
 
 

Seasonal uptake from the soil and use of nitrogen in grapevines has been examined in studies from numerous grapegrowing regions.1-3, 5-11 Uptake of other macronutrients including phosphorus, potassium, calcium and magnesium has received less attention,4,9,11 and no published study has determined the timing or quantities of micronutrient uptake of manganese, boron, zinc or copper for field-grown grapevines.

The majority of total seasonal nutrient uptake from vineyard soils (mainly for nitrogen) has been reported to occur between bloom and véraison in most studies on wine grapes (Vitis vinifera) and Concord grapes (Vitis labrusca) coincident with the increase in total vine biomass.2,3,5,6,7,9 However, some studies of wine grapes have found greater nitrogen uptake from vineyard soils between bud break and bloom than between bloom and véraison,1,8,11 even though the bulk of total vine biomass increase still occurred between bloom and véraison.

The majority of phosphorus uptake occurred early in the growing season (close to the time of flowering) in Pinot Noir,11 while the uptake for potassium, calcium and magnesium has mostly been reported between bloom and véraison.4,9,11

Given the differences observed in nutrient uptake of whole vines from previous trials, the nutrient uptake of young Pinot Noir vines was studied to provide growers with better information about the nutrient needs of young vines and when nutrient uptake occurs to provide better guidelines to manage nutrient inputs for young vineyards.

Key finding: Nutrient uptake and remobilization varies by specific nutrient
For nitrogen (N), maximal uptake from the vineyard soil occurred early in the season with most uptake occurring before bloom. Uptake of phosphorus (P) and sulfur (S) were early, with similar quantities of these elements taken up between bud break and bloom and between bloom and véraison. All other macronutrients—potassium (K), calcium (Ca) and magnesium (Mg)—and micronutrients—boron (B), zinc (Zn), manganese (Mn) and copper (Cu)—had peak uptake between bloom and véraison. Small quantities of all nutrients except N and B were taken up from the soil during the ripening period (véraison to harvest). In addition, N, P, K and S were remobilized from leaves during the ripening period to support fruit needs as well as recharging these elements in the roots.

Remobilization of nutrients from permanent vine structures helped supply early season canopy needs for N, K and S. More N was remobilized from reserves than any other nutrient, and this lasted until véraison, supplying about 35% of the canopy N between bud break and véraison. Remobilization of K and S occurred only until bloom and contributed about 30% of the canopy increase in these elements up to that time. Phosphorus was not remobilized from storage to support the developing canopy, contrary to previous results with older Pinot Noir grapevines.11 The reason for this is most likely due to the smaller root system of these young vines, combined with the fact that available soil phosphorus levels were quite low.

There was no evidence of micronutrient remobilization to support canopy needs within the young grapevines. Zinc accumulated to high levels in the fruiting cane and scion trunk, and copper accumulated in the smallest roots. Potassium accumulated in fruit clusters, and magnesium accumulated in petioles, similar to previous findings.11

The quantities discussed for each nutrient required by young Pinot Noir grapevines assumes they are carrying a typical crop yield (about 2 tons per acre) in Oregon’s Willamette Valley.

Grapevine management and nutrient analysis methods
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 micro-plots producing their first typical crop for the region. Field micro-plots (pot-in-pot vineyard) allow better control of the root environment and provide easier access to all vine roots. The more uniform soil conditions in micro-plots and use of young vines allowed micronutrient uptake to be determined for the first time under field conditions.

Vines were fertilized in the spring, and the biomass and nutrient contents of nine separate vine parts were measured at six phenological stages (bud break, bloom, véraison, harvest, leaf fall and dormancy) each year.

The grapevines (Dijon 115 clone [FPS 73] on 3309C rootstock) were grown for three years in 60-liter pot-in-pot micro-plots filled with a 1:1 (vol:vol) mixture of coarse sand and Jory series soil (a red-hill soil with low phosphorus). Each micro-plot at bud break of each year received a complete fertilizer (20-10-20) with Mg (0.15%) and micronutrients (0.05% Zn, 0.05% Mn, 0.025% B, 0.0125% Cu and 0.005% molybdenum [Mo]) to the equivalent of 30 pounds per acre N, 6.6 pounds per acre P, and 25 pounds per acre K.

Vines were drip-irrigated and water inputs managed based on measures of volumetric soil water content and vine water status.12 Vines were cane-pruned and head-trained on a single Guyot system with vertical shoot positioning. A small crop (averaging 0.5 clusters per shoot) was retained in the third growing season. In year four (experimental year), two fruit clusters were retained on each fruiting shoot. Ten vines were destructively harvested at each growth stage in 2007 and 2008. The fresh mass for each vine part was recorded, subsamples were dried and finely ground, and nutrient concentrations were determined using appropriate methods.10

Total vine biomass and total nutrient content changes between the first three growth periods (bud break to bloom, bloom to véraison, and véraison to harvest) were calculated by subtracting the mean value at an earlier growth stage from each replicate at a later growth stage.

Biomass and nutrient uptake
Biomass: Total vine biomass increased the most from bloom to véraison, increased from véraison to harvest and declined from harvest to leaf fall, remaining at that level until dormancy (see table “Relative Increase of Vine Biomass and Relative Nutrient Uptake”). While it appears from changes in biomass of sampled tissues (see “Changes in Biomass of Sampled Tissues”) that total vine biomass increased from bud break to bloom, this was not significant. However, the loss of biomass of the permanent vine structures (roots + trunk) between bud break and bloom was significant. The pattern of biomass changes found here, with peak increase between bloom and véraison, is similar to most previous whole-vine studies where roots have been accounted for.2,3,5,6,7,8,9

Nitrogen: Nitrogen uptake followed a unique pattern compared to other nutrients. Vine nitrogen uptake was greatest between bud break and bloom, followed by less uptake between véraison and harvest, with essentially no uptake after véraison (see “Changes in Nitrogen Content”). Between bud break and véraison, nitrogen was taken up from the soil and remobilized from storage in the roots and trunks to support canopy nitrogen needs.

The bulk of the nitrogen remobilized to the canopy came from the smallest roots. Remobilized nitrogen supplied 41% of canopy nitrogen requirements in 2007 and 30% in 2008 between bud break and véraison. The amount of nitrogen remobilized was less than previous findings in 23-year-old Pinot Noir vines, where approximately 50% of canopy nitrogen came from stored reserves.11

However, nitrogen remobilized in four-year-old Pinot Noir was greater than previous results in young grapevines. For example, no nitrogen remobilization occurred in three-year-old Concords, nor in two-year-old Thompson Seedless vines,1,2 and only 15%-20% of nitrogen was remobilized in two-year-old Chenin Blanc grapevines.3,5

The majority of the nitrogen that was taken up from the soil or remobilized ended up in the leaf blades, which reached maximum nitrogen content at véraison. Leaf nitrogen content declined between véraison and harvest, partly supplying fruit needs. The overall pattern for nitrogen uptake was similar to a previous study on 23-year-old Pinot Noir vines in the Willamette Valley11 but differs from other whole-vine nitrogen uptake studies.2,3,5,6,7,8,9

Phosphorus: Uptake of phosphorus was similar from bud break to bloom and from bloom to véraison, with each time period accounting for about 40% of phosphorus uptake by fruit maturity (see table “Relative Increase of Vine Biomass and Relative Nutrient Uptake”). The remaining 20% of phosphorus uptake occurred between véraison and harvest. Even though biomass in the roots and trunks decreased between bud break and bloom, the associated decrease in phosphorus content in permanent vine parts during this time was not significant. Therefore, phosphorus was not remobilized from roots and trunks to help supply canopy phosphorus 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”). Roughly similar amounts of potassium uptake (14%-20%) occurred between bud break and bloom and between véraison and harvest.

Remobilization of stored potassium (mostly from the smallest roots) helped supply 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 occurred 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 véraison, 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 accumulated 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 magnesium uptake occurred between bloom and véraison (see table). Magnesium was not remobilized in the young vines to support canopy magnesium needs.

Total vine sulfur content increased between 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 véraison, 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 between bloom and véraison (55%), and less uptake occurred between bud break and bloom (39%), and lesser still (6%) between véraison and harvest. Boron showed the biggest differences between years among all nutrients measured, because total vine boron was higher at the beginning of the growing season in 2007 than in 2008 but reached a higher level by harvest in 2008. Despite numerous interactions between year and phenology upon the boron content in various vine parts,10 boron was not remobilized from permanent vine parts to support early season canopy needs.

Zinc: The majority of zinc uptake occurred from bloom to véraison, accounting for 56% of total uptake by fruit maturity, with lesser amounts taken up between bud b reak and bloom and between véraison and harvest.

Scion trunks and fruiting canes had more zinc in 2008. Zinc accumulated to high levels in scion trunks, fruiting canes, shoots and petioles, as observed in other woody plants. The physiological benefit of accumulating high zinc levels in woody stems is not clear at this time. Zinc content increased to a small degree in woody roots and fruiting canes in each growing season, but the increases in shoots, leaves and clusters were much greater in magnitude and primarily increased whole vine content. Once these tissues were harvested, senesced or pruned away, most of the zinc accumulated in the season was lost.

Manganese and copper: Total vine manganese content increased from bud break to bloom, from bloom to véraison and from véraison to harvest, then declined from harvest to leaf fall. Manganese uptake was greatest between bloom and véraison. Total vine copper content increased from bud break to bloom, from bloom to véraison and from véraison to harvest, then declined from harvest to leaf fall. Copper uptake was greatest between bloom and véraison.

Nutrient quantities required by young Pinot Noir vines
All nutrients examined were at healthy or adequate levels in the young vines based on leaf blade and petiole concentrations, although phosphorus status was low.10 Therefore, the amount of each nutrient actually taken up provides a good estimate of young vine requirements.

Four-year-old Pinot Noir grapevines grown with irrigation and carrying a typical crop level for western Oregon took up the equivalent of 12 pounds per acre of nitrogen, 3 pounds per acre of phosphorus, 25 pounds per acre of potassium, 27 pounds per acre of calcium, 4 pounds per acre of magnesium and 1.4 pounds per acre of sulfur by harvest.

Quantities of micronutrients taken up by harvest were 1.2 ounces per acre of manganese, 0.70 ounces per acre of zinc, 0.34 ounces/acre of boron and 0.21 ounces per acre of copper. Older Pinot Noir vines took up similar quantities of nitrogen and potassium as young vines but took up less phosphorus and calcium, and more magnesium.11

R. Paul Schreiner is a research plant physiologist based at the USDA-ARS Horticultural Crops Research Laboratory in Corvallis, Ore. He thanks Matthew Scott, Jennifer Christie, Timothy Nam and Suean Ott for their technical assistance. Mention of trade names or commercial products in this article is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the U.S. Department of Agriculture.

References:
1. Araujo, F.J. and L.E. Williams. 1988 “Dry matter and nitrogen partitioning and root growth of young field-grown Thompson Seedless grapevines.” Vitis 27: 21-32.
2. Bates, T.R, R.M. Dunst and P. Joy. 2002 “Seasonal dry matter, starch, and nutrient distribution in ‘Concord’ grapevine roots.” HortScience 37: 313-316.
3. Conradie, W.J. 1980 “Seasonal uptake of nutrients by Chenin blanc in sand culture: I nitrogen. S. Afr. J. Enol. Vitic. 1: 59-65.
4. Conradie, W.J. 1981 “Seasonal uptake of nutrients by Chenin blanc in sand culture: II phosphorus, potassium, calcium and magnesium.” S Afr. J. Enol. Vitic. 2: 7-13.
5. Conradie, W.J. 1986 “Utilization of nitrogen by the grapevine as affected by time of application and soil type. S. Afr. J. Enol. Vitic. 7: 76-83.
6. Hanson, E.J. and G.S. Howell. 1995 “Nitrogen accumulation and fertilizer use efficiency by grapevines in short-season growing areas.” HortScience 30: 504-507.
7. Löhnertz, O. 1991 “Soil nitrogen and the uptake of nitrogen in grapevines.” In Proceedings of the International Symposium on Nitrogen in Grapes and Wine. J.M. Rantz (ed.), pp. 1-11. Am. Society for Enol. & Vit. Davis, CA.
8. Mullins, M.G., A. Bouquet and L.E. Williams. 1992 Biology of the Grapevine.
9. Pradubsuk, S. and J.R. Davenport. 2010 “Seasonal uptake and partitioning of macronutrients in mature ‘Concord’ grape.” J. Am. Soc. Hort. Sci. 135: 474-483.
10. Schreiner, R.P. 2016 “Nutrient uptake and distribution in young Pinot noir grapevines over two seasons.” Am. J. Enol. Vitic. 67: 436-448.
11. Schreiner, R.P., C.F. Scagel and J. Baham. 2006 “Nutrient uptake and distribution in a mature ‘Pinot noir’ vineyard.” HortScience 41: 336-345.
12. Schreiner, R.P. and J. Lee. 2014 “Effects of post-véraison water deficit on ‘Pinot noir’ yield and nutrient status in leaves, clusters, and musts.” HortScience 49: 1335-1340.

 

 
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