terclim by ICS banner
IVES 9 IVES Conference Series 9 International Congress on Grapevine and Wine Sciences 9 2ICGWS-2023 9 Energy partitioning and functionality of photosystem II in water-stressed grapevines during heatwaves revealed by continuous measurements of chlorophyll fluorescence

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

Abstract

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. To monitor the impacts of irrigation and leaf position on PSII functionality, MONI/MICRO PAM heads were mounted on the south (polar facing) and north (equatorial facing) sides of the canopy of each vine. Water stress decreased midday stem water potential (SWP) to -1.4 MPa in water-stressed plants, while well-watered plants maintained SWP at -0.8 MPa. Maximum efficiency of PSII (Fv/Fm) decreased by higher exposure to heat and radiation on the northern side, especially when plants were subjected to water stress. Absorbed energy partitioning in PSII differed between northern and southern sides, and it was influenced by irrigation. At midday, leaves on the southern side showed higher photochemical (Y(II)) and lower non-photochemical yield (Y(NPQ)) than northern leaves. Water stress decreased Y(II) and increased Y(NPQ) at midday predominantly on the northern side. During a heatwave, PSII showed an increase in photoinhibition (Y(NO)) in water-stressed plants on the northern side; however, this effect was reversible and persisted only one day following the heatwave and decreased thereafter to a similar rate to that observed in the rest of the canopy. These findings suggest that, in the short-term, irrigation can be tailored to sustain the canopy during heat waves, while in the medium-term, canopy management strategies (such as shade netting) may be needed to maintain leaf function during and following heatwaves.

DOI:

Publication date: October 5, 2023

Issue: ICGWS 2023

Type: Article

Authors

Walaa Shtai1*, Paul Petrie2, Marcos Bonada3, Massimo Tagliavini1 , Georg Wohlfahrt5, Edwards Everard4

1Free University of Bolzano- Bozen, Italy
2South Australian Research and Development Institute (SARDI), Adelaide, Australia
3Treasury Wine Estates, Adelaide, Australia.
4CSIRO Agriculture and Food, Adelaide, Australia
5University of Innsbruck, Austria

Contact the author*

Keywords

chlorophyll fluorescence, heat stress, water stress, grapevines, energy partitioning, heat dissipation, photoinhibition

Tags

2ICGWS | ICGWS | ICGWS 2023 | IVES Conference Series

Citation

Related articles…

Phenolic composition profile of cv. Tempranillo wines obtained from severe shoot pruning vines under semiarid conditions

One of the limitations of vineyards in warm areas is the loss of wine quality due to higher temperatures during the grape ripening period. In order to adapt the vineyards to these new climatic conditions, a possible solution is to delay the ripening process of the grapes towards periods with milder temperatures, by means of management practices and thus improve the quality of the fruit and the wine produced. The technique of severe shoot pruning (SSP) has proven useful in achieving this objective.

Read More

Development and validation of a free solvent UHPLC/MS-MS method to analyse melatonin and its precursors in Spanish commercial wines  

Melatonin is a bioactive compound present in foods and beverages such as wines. During alcoholic fermentation, yeast transforms tryptophan into certain indole compounds, including melatonin. This paper aims to develop and validate a free solvent analytical method by ultra-high performance liquid chromatography coupled with high resolution mass spectrometry (UHPLC/MS-MS) to determine melatonin and its precursors (L-tryptophan, tryptamine, serotonin, tryptophol, N-acetylserotonin, 5-hydroxytryptophan, and 3- indoleacetic) that appropriately prevent the matrix effect.

Read More

Extreme vintages affect grape varieties differently: a case study from a cool climate wine region

Eger wine region is located on the northern border of grapevine cultivation zone. In the cool climate, terroir selection is one of the foundations of quality wine making. However, climate change will have a significant impact on these high value-added vineyards. This study presents a case study from 2021 and 2022 with the investigation of three grape varieties (Kadarka, Syrah, Furmint). The experiment was conducted in a steep-sloped vineyard (Nagy-Eged hill) with a southern exposure.

Read More

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.

Read More

The environmental footprint of selected vineyard management practices: A case study from Logroño (La Rioja) Spain

Viticulture is globally important for socioeconomic and environmental reasons. The EU is globally leading grape and wine production, and Spain is among the top grape and wine producers. As climate change affects viticulture, mitigation and adaptation are crucial for protecting grape production. In this research work, data on viticultural management practices such as soil cultivation, irrigation, energy, machinery, plant protection and the use of fertilizers from vineyards located in Logroño (La Rioja) have been obtained.

Read More