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…

Physiological and growth reaction of Shiraz/101-14 Mgt to row orientation and soil water status

Advanced knowledge on grapevine row orientation is required to improve establishment, management and outcomes of vineyards on terroirs with different environmental conditions (climate, soil, topography) and in view of a future change to more extreme climatic conditions. The purpose of this study was to determine the combined effect of row orientation, plant water status and ripeness level on the physiological and viticultural reaction of Shiraz/101-14 Mgt.

Effects of mechanical leafing and deficit irrigation on Cabernet Sauvignon grown in warm climate of California

San Joaquin Valley accounts for 40% of wine grape acreage and produces 70% of wine grape in California. Fruit quality is one of most important factors which impact the economical sustainability of farming wine grapes in this region. Due to the recent drought and expected labor cost increase, the wine industry is thrilled to understand how to improve fruit quality while maintaining the yield with less water and labor input. The present study aims to study the interactive effects of mechanical leafing and deficit irrigation on yield and berry compositions of Cabernet Sauvignon grown in warm climate of California.

The effects of cane girdling on berry texture properties and the concentration of some aroma compounds in three table grape cultivars

The marketability of the table grapes is highly influenced by the consumer demand; therefore the market value of the table grapes is mainly characterized by its berry size, colour, taste and texture. Girdling could cause accumulation of several components in plants above the ringing of the phloem including clusters and resulting improved maturity. The aim of the experiments was to examine the effect of girdling on berry texture characteristics and aroma concentration.

Application of a fluorescence-based method to evaluate the ripening process and quality of Pinot Blanc grape

The chemical composition of grape berries at harvest is one of the most important factors that should be considered to produce high quality wines. Among the different chemical classes which characterize the grape juice, the polyphenolic compound, such as flavonoids, contribute to the final taste and color of wines. Recently, an innovative non-destructive method, based on chlorophyll fluorescence, was developed to estimate the phenolic maturity of red grape varieties through the evaluation of anthocyanins accumulated in the berry skin. To date, only few data are available about the application of this method on white grape varieties.

Different yield regulation strategies in semi-minimal-pruned hedge (SMPH) and impact on bunch architecture

Yields in the novel viticulture training system Semi-Minimal-Pruned Hedge (SMPH) are generally higher compared to the traditional Vertical Shoot Positioning (VSP). Excessive yields have a negative impact on the vine and wine quality, which can result in substantial losses in yield in subsequent vintages (alternate bearing) or penalties in fruit quality. Therefore yield regulation is essential. The bunch architecture in SMPH differs from VSP. Generally there is a higher amount but smaller bunches with lower single berry weights in SMPH compared to VSP.