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…

Impact of aging on dimethyl sulfide (DMS) in Corvina and Corvinone wines

Amarone is an Italian red wine produced in the Valpolicella area, in north-eastern Italy. Due to its elaboration with withered grapes, Amarone is a rather unique example of dry red wine. However, there is very limited data so far concerning the volatile composition of commercial Amarone wines, which also undergo a cask aging of 2-4 years before release. The present work aims at characterizing the aroma composition of Amarone and to elucidate the relationships between chemical composition and sensory characters.

Making sense of available information for climate change adaptation and building resilience into wine production systems across the world

Effects of climate change on viticulture systems and winemaking processes are being felt across the world. The IPCC 6thAssessment Report concluded widespread and rapid changes have occurred, the scale of recent changes being unprecedented over many centuries to many thousands of years. These changes will continue under all emission scenarios considered, including increases in frequency and intensity of hot extremes, heatwaves, heavy precipitation and droughts. Wine companies need tools and models allowing to peer into the future and identify the moment for intervention and measures for mitigation and/or avoidance. Previously, we presented conceptual guidelines for a 5-stage framework for defining adaptation strategies for wine businesses. That framework allows for direct comparison of different solutions to mitigate perceived climate change risks. Recent global climatic evolution and multiple reports of severe events since then (smoke taint, heatwave and droughts, frost, hail and floods, rising sea levels) imply urgency in providing effective tools to tackle the multiple perceived risks. A coordinated drive towards a higher level of resilience is therefore required. Recent publications such as the Australian Wine Future Climate Atlas and results from projects such as H2020 MED-GOLD inform on expected climate change impacts to the wine sector, foreseeing the climate to expect at regional and vineyard scale in coming decades. We present examples of practical application of the Climate Change Adaptation Framework (CCAF) to impacts affecting wine production in two wine regions: Barossa (Australia) and Douro (Portugal). We demonstrate feasibility of the framework for climate adaptation from available data and tools to estimate historical climate-induced profitability loss, to project it in the future and to identify critical moments when disruptions may occur if timely measures are not implemented. Finally, we discuss adaptation measures and respective timeframes for successful mitigation of disruptive risk while enhancing resilience of wine systems.

Región Vitivinícola del Vale dos Vinhedos (Brasil): una metodología para la definición de límites geográficos y elaboración de cartas EN escala media

Los estudios regionales presentaron en Geografía, como en otras ciencias, en este siglo, varios enfoques. Cualquiera que sea la mirada sobre el espacio, en la base de la temática regional está la concepción

Bio‐metaethics viticulture proposed by the Giesco. Direct charter with producers. Example of evaluation of training systems

The key points of the current GiESCO charter ‘BIO‐MetaEthics’ are exposed. The new development in cooperation with Giovanni Cargnello is to apply the principles and the content into the practice by establishing a direct contract with producers and other actors of the wine sector. An evaluation sheet is proposed and tested in a new advanced vineyard. For illustrating the methodology of evaluation, the example of the choice of the training systems is detailed on a wide range of situations. 

Characterization of intact glycoside aroma precursors of recovered minority Spanish red grape varieties by High-Resolution Mass Spectrometry

In Spain, the wide diversity of red grapevine varieties represents an advantage when choosing the most suitable one for cultivation based on different climatic conditions, without implying a loss of their enological potential.