Berry shrivel causes – summarizing current hypotheses

Wildfires are becoming more common in many areas of the world that are also associated with wine grape production, especially the Pacific northwest United States, Australia and even some areas of France.

Water status impact in viticulture has been widely explored, as it strongly affects grapevine physiology and grape chemical composition. It is considered as a key component of vitivinicultural terroir. Most of the studies concerning grapevine water status have focused on either physiological traits, or berry compounds, or traits involved in wine quality. Here, the response of grapevine to water availability during the ripening period is assessed through non-targeted metabolomics analysis of grape berries by ultra-high resolution mass spectrometry. The grapevine water status has been assessed during 2 consecutive years (2019 & 2020), through carbon isotope discrimination on juices from berries collected at maturity (21.5 brix approx.) for 2 Vitis vinifera cv. Pinot noir (PN) and Chardonnay (CH). A total of 220 grape juices were collected from 5 countries worldwide (Italy; Argentina; France; Germany; Portugal). Measured δ13C (‰) varied from -28.73 to -22.6 for PN, and from -28.79 to -21.67 for CH. These results also clearly revealed higher water stress for the 2020 vintage. The same grape juices have been analysed by Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR-MS) and Liquid Chromatography coupled to Mass Spectrometry (LC-qTOF-MS), leading to the detection of up to 4500 CHONS containing elemental compositions, and thus likely tens of thousands of individual compounds, which include fatty acids, organic acids, peptides, phenolics, also with high levels of glycosylation. Multivariate statistical analysis revealed that up to 160 elemental compositions, covering the whole range of detected masses (100 –1000 m/z), were significantly correlated to the observed gradients of water status. Examples of chemical markers, which are representative of these complex fingerprints, include various derivatives of the known abscisic acid (ABA), such as phaesic acid or abscisic acid glucose ester, which are significantly correlated with higher water stress, regardless of the variety. Cultivar-specific behaviours could also be identified from these fingerprints. Our results provide an unprecedented representation of the metabolic diversity, which is involved in the water status regulation at the grape level, and which could contribute to a better knowledge of the grapevine mitigation strategy in a climate change context.

Field irrigation experiments were performed on young « Nonpareil » almond trees, mature « Bartlett » pear trees and mature « Pinot Noir » grapevines, to determine the relation of a number of alternative measures of plant water status (predawn and midday stem and leaf water potential), to a number of indices of plant physiological activity (leaf conductance, vegetative growth and fruit growth and composition).

Aim: The aim of this report is to present evidence on the potential of Greek and Cypriot grape varieties to serve as a sustainable solution to mitigate climate change.

Methods and Results: The work provides a review of recent works involving Greek and Cypriot varieties’ performance under high temperatures and increased dryness.

Agroecology is an integrated approach that simultaneously applies ecological and social concepts and principles to redesign and manage food and agricultural systems, promoting agroecosystems with the necessary biological, socio-economic, and institutional diversity and alignment to support greater efficiency. Thus, several studies have been carried out at promoting the adoption of more agroecological practices among farmers and a wider audience concerning soil conservation and health maintenance.