GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 GiESCO 2019 9 Nitrogen partitioning among vine organs as a consequence of cluster thinning

Nitrogen partitioning among vine organs as a consequence of cluster thinning

Abstract

Context and purpose of the study ‐ Agroscope is investigating the impact of yield on nitrogen (N) partitioning in grapevine and on must composition. The mechanism of N assimilation, partitioning and 15 mobilization from the reserves is studied through foliar application of N isotope‐labelled urea over a two‐year period. The final scope is to optimize fertilizer use efficiency and grape composition. Here are summarized the results from the first year of experimentation.

Material and methods ‐ Two blocs (control and test) of 12 homogeneous potted grapevines each (Vitis vinifera L. Chasselas) were grown under field conditions. During summer 2017, cluster thinning allowed to create a large yield gradient (from 0.5 to 2.5 kg/m2 of soil). Vegetative development—canopy weight, leaf area, photosynthesis activity—and yield parameters —bud fruitfulness, bunch and berry weights, number of bunches and total yield per vine— were measured. All the vines were excavated at harvestand the organs were separated (roots, trunk, canopy, pomace and must), with the aim of monitoring N partitioning in the plant. The test bloc received 20 kg/ha of foliar‐applied 15N labelled urea at veraison. Total organic carbon and nitrogen and their stable isotope compositions were determined in each organ, using EA‐IRMS. The musts were analysed for their content of soluble sugars, acids, NH4+ and amino acids.

Results ‐ Grapevine compensated higher N demand from the grapes by assimilating more N through leaves and roots and mobilizing more N from reserves. The foliar supply of urea limited N mobilization from the roots, preserving the reserves for the following year. Must amino‐acid profiles varied significantly with the yield. Yield had no impact neither on vegetative development nor on grape maturation. With increasing yield, N concentration remained constant in the canopy and grapes at harvest, to the detriment of the N content in roots. Urea assimilation was positively correlated with the yield (r = 0.68, P = 0.029). Urea supply had a positive impact on yeast assimilable nitrogen concentration in the must only under higher yield conditions. 

DOI:

Publication date: June 19, 2020

Issue: GiESCO 2019

Type: Article

Authors

Thibaut VERDENAL (1,2), Jorge E. SPANGENBERG (2), Vivian ZUFFEREY (1), Agnes DIENES‐NAGY (1), Olivier VIRET (3), Cornelis VAN LEEUWEN (4), Jean‐Laurent SPRING (1)

(1) Agroscope, Av. Rochettaz 21, CH-1009 Pully, Switzerland
(2) Institute of Earth Surface Dynamics, University of Lausanne, CH-1015 Lausanne, Switzerland
(3) Direction générale de l’agriculture, de la viticulture et des affaires vétérinaires (DGAV), Av. de Marcelin 29, CH-1110 Morges, Switzerland
(4) EGFV,Bordeaux Sciences Agro, INRA, Univ. Bordeaux, ISVV, F-33882 Villenave d’Ornon, France

Contact the author

Keywords

 Nitrogen, partitioning, yield, foliar urea, isotope labelling, amino acids

Tags

GiESCO 2019 | IVES Conference Series

Citation

Related articles…

Climate ethnography and wine environmental futures

Globalisation and climate change have radically transformed world wine production upsetting the established order of wine ecologies. Ecological risks and the future of traditional agricultural systems are widely debated in anthropology, but very little is understood of the particular challenges posed by climate change to viticulture which is seen by many as the canary in the coalmine of global agriculture. Moreover, wine as a globalised embedded commodity provides a particularly telling example for the study of climate change having already attracted early scientific attention. Studies of climate change in viticulture have focused primarily on the production of systematic models of adaptation and vulnerability, while the human and cultural factors, which are key to adaptation and sustainable futures, are largely missing. Climate experts have been unanimous in recognising the urgent need for a better understanding of the complex dynamics that shape how climate change is experienced and responded to by human systems. Yet this call has not yet been addressed. Climate ethnography, coined by the anthropologist Susan Crate (2011), aims to bridge this growing disjuncture between climate science and everyday life through the exploration of the social meaning of climate change. It seeks to investigate the confrontation of its social salience in different locations and under different environmental guises (Goodman 2018: 340). By understanding how wine producers make sense of the world (and the environment) and act in it, it proposes to focus on the co-production of interdisciplinary knowledge by identifying and foreshadowing problems (Goodman 2018: 342; Goodman & Marshall 2018). It seeks to offer an original, transformative and contrasted perspective to climate change scenarios by investigating human agency -individual or collective- in all its social, political and cultural diversity. An anthropological approach founded on detailed ethnographies of wine production is ideally placed to address economic, social and cultural disruptions caused by the emergence of these new environmental challenges. Indeed, the community of experts in environmental change have recently called for research that will encompass the human dimension and for more broad-based, integrated through interdisciplinarity, useful knowledge (Castree & al 2014). My paper seeks to engage with climate ethnography and discuss what it brings to the study of wine environmental futures while exploring the limitations of the anthropological environmental approach.

How distinctive are single vineyard Gewürztraminer musts and wines from Alto Adige (Italy) based on untargeted analysis, sensory profiling, and chemometric elaboration?

Vitis vinifera L. ‘Gewürztraminer’ is a historical grape variety of Alto Adige (Südtirol), Italy, which is widely grown in the area of Tramin an der Weinstraße, but is also grown globally. It produces highly aromatic wines that are strongly influenced by the terroir of the vineyard sites where they are grown. This study looked at musts and young wines from ‘Gewürztraminer’ grapes harvested in seven distinct vineyards near Tramin and then processed at Cantina di Termeno, minimizing winemaking protocol variability. Samples were profiled using bidimensional gas chromatography–time-of-flight mass spectrometry, liquid chromatography coupled to electrochemical detection, and near-IR spectrometry. The data were subjected to Principle Component Analysis and Hierarchical Clustering Analysis. Sensory discriminant testing was undertaken using the sorting method with a semi-trained panel, and the data were processed using Multidimensional Scaling. Seven must/wine pairs could be distinguished based on their untargeted volatilome profiles and on sensory evaluation. As expected, there were greater differences in the volatile compounds between the wines than between the musts. The wines from vineyards 4 and 5 were nonetheless quite homogenous in terms of chemical and sensory analyses, as were the wines from vineyards 1 and 3. For the phenolic profile, differences were noted between the musts and wines of vineyards 2, 3, and 4, but the musts from vineyards 5 and 7 were similar. Sensory analysis showed the wines from vineyards 6 and 7 to be distinct from the rest. These results reinforce that the composition of ‘Gewürztraminer’ musts and wines is strongly determined by vineyard site, even in a small geographic area with high variability of the terroir (soil and microclimate), and that these differences are apparent in the flavours and aromas of the finished wines. Further confirmation would require a larger sample of wines, preferably from several vintages.

Combining effect of leaf removal and natural shading on grape ripening under two irrigation strategies in Manto negro (Vitis vinifera L.)

The increasingly frequent heat waves during grape ripening pose challenges for high quality wine grape production. Defoliation is a common practice that can improve the control of diseases in bunches, but also it increases the exposure to sunlight. Grapes exposed to solar radiation reach temperatures over the optimum for berry development and maturation. This makes the development of irrigation and canopy management techniques of great importance to maximize yield and grape quality. A field experiment was carried out during 2021 using Manto negro wine grapes to study the effect of applied irrigation and different light exposure levels on grape quality. Two irrigation treatments were imposed based on the frequency and amount of water doses in a four-block experimental vineyard at Bodega Ribas (Mallorca). Three light exposure treatments were randomly applied in each irrigation plot. The light treatments included exposed clusters from pea size, non-exposed clusters, and shaded clusters after softening. Leaf area index and canopy porosity was estimated every 2 weeks. Midday leaf water potential was measured weekly. Additionally, apparent electrical conductivity was measured between rows to estimate the soil water content variability. Light and temperature sensors were installed at the bunch level to quantify the differences in bunch temperature and light intensity among treatments. The effect of irrigation and cluster light exposure on berry weight, TSS, TA, malic acid, tartaric acid, K+, and pH were analysed at 5 moments along grape ripening. During different heat waves, the natural shading technique decreased the maximum bunch temperature around 10 °C respect to the exposed bunches in both irrigation strategies. The combination of defoliation and shading techniques after softening decreased TSS at harvest and affected most of the quality parameters during the last stages of ripening, showing an interesting technique to delay ripening in warm viticulture areas.

austrianvineyards.com: online viewer of all designations of Austrian wine

To digitally record and present all the origins of Austrian wines in the same perfect and clear way was the motivation for the Austrian Wine Marketing Board (Austrian Wine) to start with the project in 2018. In June 2021 the results were presented to the public in an online viewer showing all the designations of Austrian wine, available at https://austrianvineyards.com in a largely barrier-free manner. The online viewer provides tailored individual maps fitted to the respective zoom level. The smallest unit of wine-origins in Austria is called Ried and is displayed in a plot-specific manner highlighting areas under vine. Information on the Ried include administrative district, winegrowing municipality, cadastral municipality, large collective vineyard site, specific winegrowing region, generic winegrowing region, winegrowing area and, in many cases, an illustrative picture. Complementary data on the size, elevation (minimum-maximum), orientation (in 8 sectors plus flat) and gradient (minimum, maximum, average) are based on the area under vine according to the EU’s Integrated Administration and Control System. Additional information covers climate data. The diagrams are taken from the monthly breakdown of data in the annals of the Central Institute for Meteorology and Geodynamics, Austria provide a display of values for air temperature, precipitation, and sunshine hours for the reference year and the long-term average. Seasonal aggregated data on temperature, precipitation, and sunshine hours complete the display. Short descriptions with emphasis on geology and soil, field name in historical maps, etymology of the denomination, and main planted variety complements the available information for the main designations in the online viewer. These descriptions are compiled by winegrowers, geologists, historians, and journalists. All the information and data can be extracted to a pdf-file. Printed vineyard maps are also available. Missing content regarding wine origins in Styria will be completed in winter 2021/22.

Investigating the impact of grape exposure and UV radiations on rotundone in Vitis vinifera L. Tardif grapes under field trial conditions

Rotundone is the main aroma compound responsible for peppery notes in wines whose biosynthesis is negatively affected by heat and drought. Through the alteration of precipitation regime and the increase in temperature during maturation, climate change is expected to affect wine peppery typicality. In this context there is a demand for developing sustainable viticultural strategies to enhance rotundone accumulation or limit its degradation. It was recently proposed that ultraviolet (UV) radiations could stimulate rotundone production. The aim of this study was to investigate under field trial conditions the impact of grape exposure and UV treatments on rotundone in Vitis vinifera L. Tardif, an almost extinct grape variety from south-west France that can express particularly high rotundone levels. Four different treatments were compared in 2021 to a control treatment using a randomised complete block design with three replications per treatment. Grape exposure was manipulated through early or late defoliation. Leaf and laterals shoots were removed at Eichorn Lorenz growth stages 32 or 34 on the morning-sun side of the canopy. During grape maturation, UV radiations were either reduced by 99% by installing UV radiation-shielding sheets, or applied four times using the Boxilumix™ non thermal device (Asclepios Tech, Tournefeuille) with the aim of activating plant signalling pathway. Loggers displayed in solar radiation shields were used to assess the effect of such shielding sheets on air temperature within the bunch zone. The composition of grapes subjected to these treatments will be soon analysed for their rotundone content and basic classical laboratory analyses. Grapes will be harvested to elaborate wines under standardized small-scale vinification conditions (60kg) that will be assessed by a trained sensory panel.