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…

Effects of different soil types and soil management on greenhouse gas emissions 

Soil is important in the carbon cycle and the dynamics of greenhouse gases (CO2, CH4 and N2O). Key soil characteristics, such as organic matter content, texture, structure, pH and microbial activity, play a determining role in GHG emissions[1]. The objective of the study is to delimit different types of soil, with different soil management and to be able to verify the differences in CO2, CH4 and N2O emissions. The study was carried out in a vineyard of Bodegas Campo Viejo in Logroño (La Rioja), whose plant material is Vitis vinifera L. cv. Tempranillo.

Anthocyanin content and composition of Merlot grapes under temperature and late pruning conditions 

One of the main aspects of Climate Change is the increase of temperatures during summer and grape maturity period. Physiological processes are influenced by these high temperatures and result in grapes with higher sugar concentration, less acidity and less anthocyanin content among other quality changes. One strategy to deal with the climate change effects is the implementation of late winter pruning to alter the effect of high temperatures during key periods by delays in maturity time.

The tolerance of grapevine rootstocks to water deficit is related to root morphology and xylem anatomy traits 

Climate change is altering water balances, thereby compromising water availability for crops. In grapevine, the strategic selection of genotypes more tolerant to soil water deficit can improve the resilience of the vineyard under this scenario. Previous studies demonstrated that root anatomical and morphological traits determine vine performance under water deficit conditions. Therefore, 13 ungrafted rootstock genotypes, 6 commercial (420 A, 41 B, Evex 13-5, Fercal, 140 Ru y 110 R), and 7 from new breeding programs (RG2, RG3, RG4, RG7, RG8, RG9 and RM2) were evaluated in pots during 2021 and 2022.

Ultra-High Pressure Homogenization (UHPH): a technique that allows the reduction of SO2 in winemaking

Ultra-High Pressure Homogenization (UHPH) is an innovative, efficient and non-thermal technology that can be applied at different stages in winemaking in order to reduce or avoid the use of sulphites. During 2022 vintage, a batch of Xarel·lo must was processed by UHPH at 300 MPa with an inlet temperature (Ti) of 4 ºC. In order to verify the influence of the UHPH treatment in wine characteristics, alcoholic fermentations with this must (UHPH) were carried out and compared with a control batch (without SO2 addition (C)) and a sulphited batch, in which 60 mg/L of total SO2 (SO2) were added.

Cover crop management and termination timing have different effects on the maturation and water potentials of Glera (Vitis vinifera L.) in Friuli-Venezia Giulia

Inter-row soil tillage in vineyards, stimulates vigor and production due to the absence of competition for water and nutrients, however negatively affects organic matter content, soil erosion, and compaction, resulting in reduced fertility. In this study, we investigated the effects of different cover crop management approaches, including cultivation type and termination timing, on the physiological and productive responses of a Glera vineyard.
The experimental trial was conducted in Precenicco (UD) from 2019 to 2021. A commercial mixture for autumn cover cropping was sown in alternating rows, and the sowing pattern was changed each year.