terclim by ICS banner
IVES 9 IVES Conference Series 9 International Congress on Grapevine and Wine Sciences 9 2ICGWS-2023 9 Unveiling a hidden link: does time hold the key to altered spectral signatures of grapevines under drought?

Unveiling a hidden link: does time hold the key to altered spectral signatures of grapevines under drought?

Abstract

Remote sensing technology captures spectral data beyond the visible range, making it useful for monitoring plant stress. Vis-NIR (Visible-Near Infrared) spectroscopy (400-1000 nm) is commonly used to indirectly assess plant status during drought. One example is the widespread use of normalized difference vegetation index (NDVI) that is strongly linked to green biomass. However, a knowledge gap exists regarding the applicability of this method to all the drought conditions and if it is a direct correlation to the water status of the plant.

This study focused on the spectral behavior and physiological changes in leaves of two grapevine cultivars, Riesling and Pinot Noir, that were subjected to different dehydration conditions. Dehydration rates varied from quick to medium and slow, examining the effect of time on the spectral and physiological response. The goal was to determine the potential role of time influencing the consistency of responses across different water dehydration conditions, and if drought stress symptoms could be detected through Vis-NIR analysis. The experimental design included four dehydration treatments: leaf dehydration by (i) detaching the leaves, (ii) cutting the stem from the roots, (iii) removing the soil from the root zone, and (iv) natural dehydration by irrigation withholding. By monitoring the spectral and physiological changes, the study aimed to assess the impact of different dehydration timings and the detectability of associated symptoms. Our results suggest that the timing of dehydration strongly influences the spectral signature changes. In instances under comparable water potentials, plants subjected to fast dehydration (e.g., stem cutting or detached leaves) displayed spectral patterns not significantly different as compared to the ones from adequately hydrated control plants. In contrast, plants undergoing gradual dehydration over several days (e.g., via irrigation withholding) exhibited spectral modifications consistent with previously documented findings.

Acknowledgements: Supported by the Projects DigiPlant and ImStress funded by NÖ Forschungs- und Bildungsges.mbH (NFB), Neue Herrengasse 10, 3rd floor, 3100 St. Pölten, Austria. We sincerely thank Rudi Rizzoli and Soma Laszlo Tarnay for their valuable contributions to the plants management, which played a crucial role in the research project.

DOI:

Publication date: October 3, 2023

Issue: ICGWS 2023

Type: Article

Authors

Flagiello F.1*, Herrera J.C.2, Farolfi E.2, Innocenti J.2, Kulhánková A.3, Bodner G.1

1 Institute of Agronomy, Department of Crop Sciences, University of Natural Resources and Life Sciences Vienna (BOKU), Tulln, Austria
2 Institute of Viticulture and Pomology, Department of Crop Sciences, University of Natural Resources and Life Sciences Vienna (BOKU), Tulln, Austria
3 Department of Horticulture, Faculty of Agrobiology, Food and Natural Resources, The Czech University of Life Sciences Prague, Prague 165 21, Czech Republic.

Contact the author*

Keywords

climate change, hyperspectral analysis, viticulture, drought stress, grapevine

Tags

2ICGWS | ICGWS | ICGWS 2023 | IVES Conference Series

Citation

Related articles…

Glucosidase and esterase salivary activities and their involvement in consumer’s wine sensory perception and liking

Wine flavour is the integration of distinct physiologically defined sensory systems that combine taste, aroma and trigeminal sensations, and it is a key determinant factor for the acceptance of wine by consumers. Volatile compounds, are important contributors to wine flavour, specially to aroma. These small and low-boiling point compounds are easily released into the air allowing to enter and move within the nasal or oral cavities where they can bind the olfactory receptors. Additionally, wine also contains aroma precursors, which are non-volatile compounds, but that can be broken down releasing volatile odorants. During wine tasting, all these chemicals (volatiles and non-volatiles) can be submitted to the action of salivary enzymes.

Water availability at budbreak time in vineyards that are deficitary irrigated during the summer: Effect on must volatile composition


In recent years, Mediterranean regions are being affected by marked climate changes, primarily characterized by reduced precipitation, greater concurrence of temperature extremes and drought during the growing season, and increased inter-annual variability in temperatures and rainfall. Generally, high-quality red wines need moderate water deficit. Hence, irrigation may be needed to avoid severe vine water stress occurring in some vintages and soils with low holding capacity. The aim of this work was to evaluate the effects of soil recharge irrigation in pre-sprouting and summer irrigation every week (30 % ETO) from the pea size state until the end of ripening (RP) compared to exclusively summer irrigation every week (R) in the same way that RP, on must volatile composition at harvest.

New tool to evaluate color modifications during oxygen consumption in white and red wines

Measuring the effect of oxygen consumption on the color of wines as the level of dissolved oxygen decreases over time is very useful to know how much oxygen a wine can consume without significantly altering its color. The changes produced in wine after being exposed to high oxygen concentrations have been studied by different authors, but in all cases the wine has been analyzed once the oxygen consumption process has been completed. This work presents the results obtained with the use of an equipment designed and made to measure simultaneously the level of dissolved oxygen and the spectrum of the wine, during the oxygen consumption process from saturation levels with air to very low levels, which indicate the total consumption of the dosed oxygen[1,2].

Combined use of leaf removal and natural shading to delay grape ripening in Manto negro (Vitis vinifera L.) under deficit irrigation 

The increasingly frequent heat waves during grape ripening pose challenges for premium wine grape production. 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 and 2022 using Manto negro wine grapes to study the effect of two irrigation strategies and different light exposure levels on grape quality.

Response of red grape varieties irrigated during the summer to water availability at the end of winter in four Spanish wine-growing regions: berry phenolic composition

Water availability is the most limiting factor for vineyard productivity under Mediterranean conditions. Due to the effects caused by the current climate change, wine-growing regions may face serious soil moisture conservation problems, due to the lower water retention capacity of the soil and higher soil irradiation. The aim of this work was to evaluate the effects of soil recharge irrigation in pre-sprouting and summer irrigation every week (30 % ETo) from the pea size state until the end of ripening (RP) compared to exclusively summer irrigation every week (R) in the same way that RP, on berry phenolic composition at harvest.