Nitrogen Requirements of Pinot noir Based on Growth Parameters, Must Composition, and Fermentation Behavior

Abstract

A study to reassess the nitrogen (N) requirements for Pinot noir was carried out using a pot-in-pot vineyard where N inputs were carefully controlled. Pinot noir grafted on 101-14 rootstock was exposed to five levels of N supply beginning in their fourth growing season, and vine productivity, berry chemistry, and must fermentation dynamics were studied over three years. N supply altered the N status of vines in accordance with expectations. Varying N had a greater impact on vegetative growth parameters than upon reproductive responses. For example, at veraison, leaf area of vines exposed to the three lowest rates of N was reduced in all years, but yield was only reduced at the lowest N rate in the first year and at the two lowest N rates in subsequent years. Fruitfulness and fruit set were reduced slightly by low N, while flower number of inflorescences was unaffected. Effects on berry maturity indices at harvest were generally small, but effects on must yeast assimilable nitrogen (YAN) concentrations were large. YAN was reduced from ~200 mg N/L in the Control to as low as 25 mg N/L at the lowest N rate after three years. Treatments with lower YAN required more time to complete alcoholic fermentation, particularly those with YAN below 100 mg N/L. However, all musts fermented to dryness. Reducing vegetative growth of Pinot noir can be achieved prior to reducing yield by reducing N status when vines are cropped at levels typical for premium wine production in the region. YAN levels as low as 100 mg N/L may be a better production target for wineries to achieve minimum fermentation requirements of Pinot noir.

Understanding and managing nitrogen nutrition in grapevine: a review

“…N status alters both vine production variables and grape composition to different degrees (Schreiner et al, 2018). Vegetative growth is more constrained than reproductive growth as N status decreases, as illustrated in Figure 1.…”

“…The production of 1 kg of biomass requires from 20 to 50 g of N (Xu et al, 2012). Grapevine N requirements are rather modest in comparison to nonperennial crops, even with high production objectives (Metay et al, 2014), and have already been studied under different environmental conditions (Löhnertz, 1988;Porro et al, 2007;Schreiner et al, 2018). In the context of the sustainable production of 12 tons/ha of grape in cool climate, Löhnertz (1988) estimated the average grapevine N requirement to be 50 kg/ha per year (Table 1).…”

“…N deficiency results in weak vine growth, short inter-nodes, small and light-green to yellow leaves, low berry set, reduced long-term bud fruitfulness and yield (Guilpart et al, 2014), reduced grape N content and possible delayed maturation (Schreiner et al, 2018). (Löhnertz, 1988).…”

Identification of putative chemical markers in white wine (Chasselas) related to nitrogen deficiencies in vineyards

“…Tahim et al (2019) reported an optimal YAN value of 130 mg N/L for cool-climate Riesling. In the case of red cultivars, which are fermented along with the skin, even lower values have been reported: 100 mg N/L for Pinot Noir (Schreiner et al, 2018) and 60 mg N/L for Merlot (Stockert et al, 2013). This can be explained by the contribution of N contained in the skin, which is about 29 % of the berry's total YAN (Stines et al, 2000).…”

Bee Pollen as Oenological Tool to Carry out Red Winemaking in Warm Climate Conditions

“…Depending on its potential alcoholic strength and fermentation conditions, inorganic and organic nitrogen, as well as ammonium salts and amino acids [14], should be found in grape-musts at over 140 mg/L [4,[14][15][16][17][18][19][20]. However, such a concentration level and other compound concentrations may vary depending on the geographical location of the vineyard [21], the cultivar [22] or the rootstock used [23,24], and viticulture techniques that are implemented [23,25,26]. Since wine making yeasts 2 of 16 metabolize both YAN and other nutrients while growing and developing biomass [27] as part of the vinification process, a proper YAN level is essential both for indigenous yeasts and commercial strains of active dry yeast [18,[28][29][30].…”