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…

High-throughput sequencing analysis based on nematode indices revealed healthier soils of organic vineyards 

Proper soil health assessments are crucial for sustainable cropland. Among the widely employed approaches, evaluating nematode community structure is particularly suitable. Traditionally, the taxonomic characterization of soil nematodes has relied on time-consuming morphology-based methods requiring experienced experts. However, molecular tools like high-throughput sequencing have emerged as efficient alternatives. In this study, we performed a metataxonomic analysis of soil samples collected from 57 vineyards in the DOCa Rioja region of Northern Spain, focusing on the impact of organic viticulture and cover cropping compared to integrated pest management (IPM) and tilling practices.

Oxidability of wines made from Spanish minority grape varieties

The phenolic profile of a wine plays an essential role in its oxidative capacity and in both white and red wines it defines its shelf life[1]. The study of minority varieties to produce wines with peculiar characteristics necessarily includes the phenolic and oxidative characterization of the wines produced. This paper presents the study of wines made from 24 minority and majority white and red grape varieties, focusing on phenolic characteristics (total phenols, slightly polymerized phenols, highly polymerized phenols, anthocyanins…), color, as well as parameters related to the oxidability of the wines and their capacity to consume oxygen [2].

Evaluation of physiological properties of grapevine clones of ‘Tempranillo’ and ‘Graciano’ in DOCa Rioja (Spain)

In order to avoid the loss of grapevine intra-varietal diversity of DOCa Rioja grape varieties, Regional Government of La Rioja established a germplasm bank with more than 1.600 accessions, whose origin lies in the prospecting and sampling of ancient vineyards located throughout the whole region. 30 clones of Tempranillo and 13 clones of Graciano were preselected and multiplied in a new vineyard for further observations. The aim of this work is to describe the first results from the physiological characterization by an optical sensor of these preselected clones, which constitute the base of a new clonal selection that aims to increase the range of available certified clones and to improve the adaptation of these varieties to future objectives and environmental conditions.

Possible methods of adaptation to the effects of climate change in the Tokaj Wine Region 

Viticulture’s adaptation to the harmful effects of climate change is globally the biggest challenge of the near future. Short, extremely intensive rainfalls and longer periods of drought are getting more frequent in the Tokaj Wine Region, where the majority of the vineyards are cultivated on steep slopes. Hence, erosion has high risk, especially when combined with the loess-based soils on about ten percent of the region. The environmentally beneficial cover crop and mulch usage can effectively reduce the risk of erosion, according to research done by the Tokaj Wine Region Research Institute of Viticulture and Oenology.

Energy partitioning and functionality of photosystem II in water-stressed grapevines during heatwaves revealed by continuous measurements of chlorophyll fluorescence

The increased intensity and frequency of heatwaves, coupled with prolonged periods of drought, are a significant threat to viticulture worldwide. During these conditions the more exposed leaves can show visible symptoms of heat damage. We monitored the functionality of photosystem II (PSII) in the field to better understand the impact of heatwaves on canopy performance. A factorial experiment was established in summer 2023 using Shiraz grapevines in the Barossa valley of South Australia, involving water-stressed and well-watered vines.