Terroir 2020 banner
IVES 9 IVES Conference Series 9 Variety specific thresholds for plant-based indicators of vine nitrogen status

Variety specific thresholds for plant-based indicators of vine nitrogen status

Abstract

Aim: Several plant-based indicators of vine N status are reported in the literature. Among these, yeast assimilable nitrogen in grape must (YAN) and total N concentration of petiole and leaf blades are considered to be reliable indicators and so is the chlorophyll index, measured with a device called N-tester. The N-tester index is used to measure the intensity of the green colour of the leaf blade, and therefore to estimate its chlorophyll content. The aim of this study is to measure the nitrogen content of various grapevine organs (petiole, leaf blade, grape must) and the intensity of the green colour of leaf blades, in order to establish variety specific thresholds for the interpretation of plant-based indicators of vine nitrogen status.

Methods and Results: To study the varietal effect on indicators of vine N status, the latter were measured during 4 years on 35 grapevine varieties grafted on the same rootstock and planted with replicates in an experimental vineyard in the Pessac-Léognan appellation in Bordeaux. The results of N-tester measurements carried out at mid-flowering and mid-véraison were compared with the nitrogen content of leaf blades and petioles at véraison and the concentration of yeast assimilable nitrogen (YAN) in the must at maturity. 

Conclusions: 

Strong varietal and year effects were observed for all indicators. Leaf blade nitrogen showed the lowest variability and YAN the highest. The N-Tester values recorded at mid-flowering were more consistent than those at mid-véraison.

Significance and Impact of the Study: Among the nutrients required by the vine, nitrogen is one of the most important. It is an essential factor in vegetative and reproductive development. Vine nitrogen status influences grape composition and wine quality. In addition, a low concentration of assimilable nitrogen in the must causes fermentation problems because N is one of the essential substrates for yeast growth. Vine N status depends on environmental factors (soil and climate) but can be managed through fertilisation and vineyard floor maintenance. Hence, plant-based indicators for vine nitrogen status are of utmost importance to optimize management practices for obtaining high wine quality and sustainable yields. The data generated by this experiment can help to take into account varietal specific responses to nitrogen availability when establishing thresholds for plant-based indicators of vine N-status. An example is provided for N-tester values at mid-flowering.

DOI:

Publication date: March 17, 2021

Issue: Terroir 2020

Type: Video

Authors

Agnès Destrac-Irvine, Elisa Marguerit, Mark Gowdy, Bruno Suter, Julien Fort, Francesco Rinaudi and Cornelis van Leeuwen 

EGFV, Bordeaux Sciences Agro, INRAE, Univ. Bordeaux ISVV, F-33882 Villenave d’Ornon, France

Contact the author

Keywords

Vine nitrogen status, petioles, leaf blades, must

Tags

IVES Conference Series | Terroir 2020

Citation

Related articles…

Crown procyanidin quantification in red wines, rosé wines and Port wines

Condensed grape tannins play a major role in the organoleptic properties and quality of red wine. Recently, a new sub-family of macrocyclic condensed tannins has been identified in red wine and named “crown tannins”. Indeed, the first compound of the family identified and characterised by NMR was the crown procyanidin tetramer which is composed of a macrocyclic structure composed of four (-)-epicatechins link together by B-type interflavanoid linkage in the following an alternative sequences of C4-C8 and C4-C6 linkage. The 3D structure of this unusual crown procyanidin family reveals a central cavity in the molecule [1].

How to transform the odor of a white wine into a red wine? Color it red!

Does a white wine smell like red wine if you color it with red food coloring? A study by Morrot, Brochet, and Dubourdieu (2001, Brain and Language) suggests so. Subjects perceived red wine odors when tasting white wine that had been colored red. The perceived odor profile of the colored white wine became similar to that of a red wine. However, the forced-choice procedure used by Morrot et al. has some methodological shortcomings. Here, we used an alternative method (a rating procedure) to evaluate the presented wines.

applicazione dei metodi isotopici e dell’analisi sensoriale negli studi sull’origine dei vini

Traceability of agro-alimentary products is very important to certify their origin. This work aimed to characterize wines obtained by the same cultivar (Nero d’Avola and Fiano) – grown in regions with different soil and climate conditions during three vintages (2003-2005) – employing isotopic analyses (NMR and IRMS) and sensory analyses.

Climat-roche-sol-fromage. Cartographie fonctionnelle du terroir. Exemple de l’A.O.C. Comté

La place prépondérante que prend le Massif Jurassien en Franche-Comté confère à la région un caractère montagneux qui a orienté l’agriculture vers l’élevage laitier. Cette vocation pastorale marquée et de rudes conditions climatiques sont à l’origine de la production, attestée depuis l’Antiquité, d’un fromage de réserve pour la longue période hivernale. Cette tradition fromagère, liée à des prairies naturelles, a perduré jusqu’à nos jours. La qualité et la spécificité du produit actuel, le fromage de Comté, ont été reconnues dès 1952 par l’attribution d’un label et dès 1958, par la reconnaissance d’un périmètre d’appellation d’origine contrôlée, l’A.O.C. Comté (fig. 1).

Physiological and performance responses of grapevine rootstocks to water deficit and recovery 

Rootstocks play a key role in the grapevine’s adaptation to the increasing soil water scarcity related to climate change. A pot experiment carried out in 2022 aimed at assessing the physiological responses of seven ungrafted rootstocks to a progressive soil water deficit and a subsequent recovery to field capacity.