GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 Mapping plant water status to indirectly assess variability in grape flavonoids and inform selective harvest decisions

Mapping plant water status to indirectly assess variability in grape flavonoids and inform selective harvest decisions

Abstract

Context and purpose of the study – Plant water stress affects grape (Vitis vinifera L.) berry composition and is variable in space due to variations in the physical environment at the growing site. Could we use water status maps as a sensitive tool to discriminate between harvest zones?

Material and methods – The study was carried out on 35experimental units placed on an equidistant grid within a 3.5 ha vineyard located in Sonoma County, Northern California. This drip irrigated vineyard was planted with Cabernet-Sauvignon on 110R, spur pruned and trained in two single high wires in a horizontally split canopy. The site was described through a digital elevation model, terrain analysis, NDVI and electrical resistivity maps. The natural variability of grapevine water stress was monitored by stem water potential (Ψstem), leaf gas exchange and δ13C of grape must at harvest. Geospatial analysis and clustering were used to differentiate the vineyard block into two management zones according to variability in water status.

Results – The two management zones were very distinct in water status and presented severe and moderate water stress. The average difference in Ψstem between the zones was of 0.2 MPa. Differences in stem water potential affected stomatal conductance, net carbon assimilation, and intrinsic water use efficiency that were different in all measurement dates. The two zones were selectively sampled at harvest for measurements of berry chemistry. Berry mass and yield per vine in the two water status zones were not different. A significant difference in total soluble solids (3.56 Brix) and in titratable acidity indicated a direct effect of water stress on ripening acceleration. Berry skin flavonol and anthocyanin composition and concentration were measured by C18 reversed-phased high-performance liquid chromatography (HPLC). Berry anthocyanins showed the highest differences between the two water stress zones. Dihydroxylated anthocyanins were more affected than the trihydroxylated ones, therefore, the ratio of the two forms increased. Flavonols were different in total amounts, but hydroxylation patterns were not affected. Proanthocyanidin isolates were characterized by acid catalysis in the presence of excess phloroglucinol followed by reversed-phase HPLC. Proanthocyanidins showed the least significant difference, although (+)-catechin terminal subunits were important predictors in a partial least square model used to summarize the multivariate relationships, predicting Ψstem or the management zone. The results highlight the importance of vineyard water status information for differential harvesting or direction to vineyard operators to modify irrigation management to equilibrate berry composition at harvest.

Download the PDF

DOI:

Publication date: September 27, 2023

Issue: GiESCO 2019

Type: Poster

Authors

Luca BRILLANTE1*, Luis SANCHEZ2, Johann MARTINEZ-LUSHER3, Runze YU3, S. Kaan KURTURAL3

1 Dep. of Viticulture and Enology, California State University, Fresno, CA 93740. USA
2 E. J. Gallo Winery, 1541 Cummins Drive, Modesto, California 95358, United States
3 Department of Viticulture and Enology, University of California, Davis, CA 95616, USA

Contact the author

Keywords

selective harvest, spatial variability, management zones, water stress, anthocyanins, flavonols, proanthocyanidins

Tags

Citation

Related articles…

Spatial determination of areas in the Western Balkans region favorable for organic production

In problematic conditions for production of grapes and wine caused by the COVID-19 pandemic and the resulting occurrence of wine surpluses, producers are increasingly turning to the innovative viticulture and winemaking of products that are more appealing to the market and the consumers. On the other hand, consumption of the food safety or organic products, and therefore of organic grapes and wine, is increasingly common in the world, in particular in Europe. The Regional Rural Development Standing Working Group (SWG RRD), as a regional intergovernmental organization gathers actors in the viticulture and winemaking sector from states and territories of the Western Balkans (South-East Europe) in the Expert Working Group for Wine, with the aim of improving viticulture and winemaking in this region through joint activities. In accordance with the aforementioned, the SWG RRD is working on advancing organic production of grapes and wine, and on recognition of specificities of the terroir of wine-growing areas in Western Balkans. In addition, as part of the project “Facilitation of Exchange and Advice on Wine Regulations in Western Balkan Countries” helmed by the German Federal Ministry of Food and Agriculture, in addition to harmonization of relevant legislation with EU regulations, efforts are being invested towards recognition of organic wines. Within activities and project implemented by this organization, expert analyses and scientific research of the terroir of Western Balkans were carried out, and some of the results are presented in this paper.

Read More

Vineyard soil mapping to optimise wine quality: from ‘terroir’ characterisation to vineyard management

In this study, a soil mapping methodology at subplot level (scale 1:5000) for vineyard soils was developed. The aim of this mapping method was to establish mapping units, which could be used as basic units for ‘terroir’ characterisation and vineyard management (precision viticulture).

Read More

Enhancing vine resilience and protecting grape production in Mediterranean vineyards: the role of anti-hail shading nets and kaolin applications

Climate change and rising temperatures present a substantial challenge to viticulture, intensifying summer heat stress and accelerating berry ripening.

Read More

Automated red microvinification (1kg) adapted to the needs of varietal innovation

The creation of disease-resistant varieties adapted to climate change is a key challenge for the future of the wine industry. At present, the selection of these new varieties is essentially based on screening for genetic markers of resistance and agronomic criteria, due to the small number of vines available per genotype. Integrating screening for oenological criteria into the early stages of selection would speed up this process.

Read More

Vineyard management practices to reduce sugar content on ‘Monastrell’ grapes

Climate change is resulting in more dry and hot summers, accelerating grape ripening and increasing berry sugars concentration. This results in wines with a higher alcohol content, which has a negative impact on wine quality, as well as, on consumer health. Agronomic practices that minimize these effects on berry composition and, consequently, on wine quality must be defined. In this work, different management practices have been assessed on rainfed ‘Monastrell’ grapevines in Jumilla (Murcia, Spain) from 2021 to 2023 vintages. Mulching, shading, application of kaolin and different types of pruning were evaluated, among others field adaptation practices.

Read More