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…

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.

Applicability of grape native yeasts to enhance regional wine typicity

The universalization in wine production has been restricting the imprint of terroir in regional wines, resulting in loss of typicity. Microbes are the main driving force in wine production, conducting fermentation and originating a myriad of metabolites that underly wine aroma. Grape berries harbor an ecological niche composed of filamentous fungi, yeasts and bacteria, which are influenced by the ripening stage, cultivar and region. The research project GrapeMicrobiota gathers a consortium from University of Zaragoza, University of Minho and University of Tours and aims at the isolation of native yeast strains from berries of the wine region Douro, UNESCO World Heritage, towards the production of wines that stand out in the market for their authenticity and for reflecting their region of origin in their aroma.

Green pruning of shoots to force new sprouting of buds, in fruit set and in pea size: vegetative, productive and maturation effects, in cv. Verdejo

The context of climate crisis leads to the acceleration of technological ripening of grapes, with unsuitable loss of acidity, so various vineyard management alternatives are being considered to delay the grape ripening. The delay of the vegetative cycle towards a period of milder temperatures affects ripening, but vine behavior can vary according to the area, conduction, watering, variety, etc. A work is proposed to know the response to the green pruning of shoots, executed in fruit set and in pea size, in cv. Verdejo.

Evaluation of phenology, agronomic and oenological quality in minority wine varieties in Madrid as a strategy for adaptation to climate change

The main phenological stages (budburst, flowering, veraison, and ripeness) and the fruit composition of 34 Spanish minority varieties were studied to determine their cultivation potential and help winegrowers adapt their production systems to climate change conditions. In total, 4 control cultivars, and 30 minority varieties from central Spain were studied during a period of 3 campaigns, in the ampelographic collection “El Encín”, in Alcalá de Henares, Madrid. Agronomic and oenological characteristics such as yield, and total soluble solids concentration have been monitored.

Effect of ultraviolet B radiation on pathogenic molds of grapes

The fungicidal effect of UV-C radiation (100-280 nm wavelength) is well known, but its applicability for the control of pathogenic molds of grapes is conditioned by its effect on the host and by the risks inherent in its handling[1].
As an alternative, the effect in vitro of UV-B radiation (280-315 nm) on the main pathogenic molds of grapes has been studied: Botrytis cinerea, Aspergillus niger, Penicillium expansum and Rhizopus stolonifer.