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…

Grouping Vitis vinifera grapevine varieties based on their aromatic composition

Climate change is likely to impact wine typicity across the globe, raising concerns in wine regions historically renowned for the quality of their terroir1. Amongst several changes in viticultural practices, replacing some of the planting material (i.e. clones, rootstocks and cultivars) is thought to be one of the most promising potential levers to be used for adapting to climate change. But the change of cultivars also involves the issue of protecting the region’s wine typicity. In Bordeaux (France), extensive research has been conducted on identifying meridional varieties that could be good candidates to help guard against the effects of climate change2 while less research has been done concerning their impacts on Bordeaux wine typicity.

Association between dietary pattern and wine consumption and Alzheimer’s disease in a cohort from La Rioja (Spain)

Addressing modifiable risk factors is the most promising strategy to prevent/delay Alzheimer Disease (AD)[1]. The aim of the study was to establish the connections between dietetic habits, wine consumption and AD. Thus, 98 volunteers were recruited: 50 diagnosed as AD and 48 healthy/controls. The Food Frequency Questionnaire (FFQ) was used for dietary patterns assessment and, based on these data, the Mind Diet Score was calculated. (Poly)phenol metabolites (especially derived from wine consumption) were analyzed by UPLC-QqQ-MS/MS in 24-h urine samples to confirm dietary (poly)phenol consumption.

Pruned vine biomass exclusion from a clay loam vineyard soil – examining the impact on physical/chemical properties

The wine industry worldwide faces increasing challenges to achieve sustainable levels of carbon emission mitigation. This project seeks to establish the feasibility of harvesting winter pruned vineyard biomass (PVB) for potential use in carbon footprint reduction, through its use as a renewable biofuel for energy production. In order to make this recommendation, technical issues such as the potential environmental impact, chemical composition and fuel suitability, and logistical challenges of harvesting biomass needs to be understood to compare with the results from similar studies. Of particular interest is the role PVB plays as a carbon source in vineyard soils and what effect annual removal might have on soil carbon sequestration. A preliminary trial was established in the Waite Campus vineyard (University of Adelaide) to test current management strategies. Vines are grown in a Eutrophic, Red Dermosol clay loam soil with well managed midrow swards. A comparison was undertaken of mid-row treatments in two 0.25 Ha blocks (Shiraz and Semillon), including annual cultivation for seed bed preparation, the deliberate exclusion of PVB (25 years) and incorporation of PVB (13 years) at an average of 3.4 and 5.5 Mg/Ha-1 for Shiraz and Semillon respectively. In both 0-10cm and 10-30cm soil core sample depths, combined soil carbon % measures in the desired range of 1.80 to 3.50, were not significantly different between treatments or cultivars and yielded an estimated 42 Mg/ha-1 of sequestered soil carbon. Other key physical and chemical measures were likewise not significantly different between treatments. Preliminary results suggest that in a temperate zone vineyard, managed such as the one used in this study, there is no long term negative impact on soil carbon sequestration through removing PVB. This implies that growers could confidently harvest PVB for use in several end fates including as a bio fuel.

Use of minority grape varieties to mitigate climate change and achievement of balanced wines in Castilla y León (Spain)

Castilla y León is the third longest region in the European Union, having more than 85.000 vineyard hectares.

Climatic zoning of viticultural production periods over the year in the tropical zone: application of the methodology of the Geoviticulture MCC system

L’objectif de cette recherche est le zonage climatique des périodes viticoles de l’année dans la Vallée du São Francisco, région brésilienne productrice de vins située en climat tropical semi-aride. Dans cette région, la production peut être échelonnée sur tous les mois de l’année.