terclim by ICS banner
IVES 9 IVES Conference Series 9 GiESCO 9 Grapevine nitrogen status: correlation between chlorophyll indices n-tester and spadGrapevine nitrogen status

Grapevine nitrogen status: correlation between chlorophyll indices n-tester and spadGrapevine nitrogen status


Context and purpose of the study – Knowledge of the nitrogen nutrition status of grapevines is essential for the sustainable management of their nutrition for the production of quality grapes. The measurement of the chlorophyll index is a rapid, non-destructive and relatively inexpensive method that provides a good approximation of the nitrogen nutrition status of the vine during the season. Interpretation thresholds are currently insufficient or non-existent for some chlorophyll meters. Ideally, they should be available for each variety and each phenological stage. In order to popularize the use of chlorophyll-meters, measurements were carried out at Agroscope in Switzerland to establish the correlation between the indices obtained by the devices N-tester and SPAD 502.

Material and methods – In 2022, 500 measurements were carried out with the two devices N-tester and SPAD 502 in parallel, at three phenological stages (flowering, veraison and post-harvest), on the two grape varieties chasselas and pinot noir. The vines were all trained in Guyot pruning. Each measurement consisted of 30 flashes of each device taken at the same locations on the main leaves of the fruit zone.

Results – Measurements from both devices showed an excellent correlation (r = 0.97; P < 0.0001) between SPAD and N-tester indices. Given the linear regression obtained (y = 0.06x + 6.25), the thresholds of the SPAD index measured on vines at veraison, for the interpretation of the nitrogen nutrition status, were calculated from the correlation with the N-tester index, whose thresholds are already known. It is not recommended to carry out measurements at other times of the season due to the greater fluctuation of the data due to the age of the leaves, the water status of the vine or the possible presence of disease symptoms (e.g., mildew, powdery mildew) or other deficiencies (e.g., iron, magnesium). These results allow scientists and growers to easily estimate the nitrogen status of the vine at veraison in the vineyard and, if necessary, to compare/convert the results of the two devices.


Publication date: July 5, 2023

Issue: GiESCO 2023

Type: Poster


Thibaut Verdenal*, Vivian Zufferey, Jean-Sébastien Reynard, Jean-Laurent Spring

Agroscope, avenue Rochettaz 21, 1009 Pully, Switzerland

Contact the author*


vine, nitrogen, chlorophyll, thresholds, fertilization


GiESCO | GIESCO 2023 | IVES Conference Series


Related articles…

An excessive leaf-fruit ratio reduces the yeast assimilable nitrogen in the must

Yeast assimilable nitrogen (YAN) in the grape must is a key variable for wine quality as a source of aroma precursors. In a situation of YAN deficiency, a foliar urea application upon the vine at veraison enhances YAN concentration and facilitates must fermentation. In 2013, Agroscope investigated the impact of leaf-fruit ratio on the nitrogen (N) assimilation and partitioning in grapevine Vitis vinifera cv. Chasselas following foliar-urea application with the aim of improving its efficiency on the YAN concentration.

Extraction of polyphenols from grape marc by supercritical fluid extraction (SFE) and evaluation of their ‘bioavailability’ as dietary supplements

In the winemaking process, several compounds that remain in the grape skins and seeds after the fermentation stage are bioactive-compounds (substances with potential beneficial effects on health) that can be extracted in order to recovery valuable substances with a high commercial value for the cosmetic, food (nutraceuticals) and pharmaceutical industries. The skins contain significant amounts of bioactive substances such as tannins (16-27%) and other polyphenolic compounds (2-6.5%) in particular, catechins, anthocyanins, proanthocyanins, quercetin , ellagic acid and resveratrol.

The impacts of frozen material-other-than-grapes (MOG) on aroma compounds of red wine varieties

An undesirable note called “floral taint” has been observed in red wines by winemakers in the Niagara region caused by large volumes of frozen leaves and petioles [materials-other-than-grapes (MOG)] introduced during mechanical harvest and subsequent winemaking late in the season. The volatiles, which we hypothesized are responsible, are primarily terpenes, norisoprenoids, and specific esters in frozen leaves and petioles. The purpose of this study was to investigate the volatile compounds which may cause the floral taint problem and explore how much of them (thresholds) may lead to the problem. Also, the glycosidic precursors of some of these compounds were analyzed to see the changes happening during frost events.

Aromatic profile of six different clones of Chardonnay grape berries in Minas Gerais (Brazil)

Aromas are one of the key points in food analysis since they are related to character, quality and consequently consumer acceptance. It is not different in the winery industry, where the aromatic profile is a combination of viticultural and oenological practices. Based on the development of more aromatic clones and on the potential to produce sparkling wines at Caldas, in the southern region of Minas Gerais (Brazil) (21°55´S and 46°23´W, altitude 1,100m), the aim of this work was the determination of volatile compounds in six different clones of Chardonnay grape berries to better understand which compounds add bouquet to the wine, and additionally comprehend the impacts of the edaphoclimatic and annual conditions on the improvement of grape-growing and winemaking practices.

Improving stilbenes in vitis Labrusca L. Grapes through methyl jasmonate applications

Grapes (Vitis sp.) are considered a major source of phenolic compounds such as flavonols, anthocyanins and stilbenes. Studies related to the beneficial effects of these compounds on health have encouraged research aimed at increasing their concentration in fruits. On this behalf, several plant growth regulators such as jasmonic acid and its volatile ester, methyl-jasmonate (MeJa), have demonstrated promising results in many fruits. However, Brazilian subtropical climate might interfere on treatment response. The present study aims to evaluate the application of MeJa in the pre-harvest period in Concord and Isabel Precoce grapes (Vitis labrusca L.).