Aim of the study & methods
To investigate the effect of age and pruning characteristics on grapevine hydraulic conduction, a study was carried out between 2017 and 2020. Two pruning regimes (respecting or not respecting sap flow pathways) and two vine age levels (older and younger vines) were considered and compared on two different vineyard plots. One plot is in the French northeast Jura region, and the other is in southwest Bordeaux. The assessment of pruning characteristics in relation to sap flow pathways was based on a visual characterisation of the external wood aspect of the trunk and arms. It consisted of criteria involving the number, size, and position of pruning wounds.
Sap flow measurements of entire vine plants were carried out using the Xyl’em® tool and an assessment of the necrotised, living, and conductive xylem area in the trunks and arms after Phloxine staining. The biomass of the vegetation was also assessed.
Results
Results showed that vines pruned without considering the sap flow pathways had 40-to-50% less conductive sap flow than vines pruned considering the sap pathway. No difference was observed with vine age within each pruning regime. However, for the vineyard plot where the amount of conductive xylem area was assessed, older vines that were not pruned to respect the sap pathways showed a smaller area of living wood as well as conductive wood than the older ones pruned to respect the sap flows. The amount of living and conductive areas of these vines was equivalent to that of younger vines pruned to respect sap pathways. These older vines also showed less vegetative biomass.
Significance of the study
These results show that pruning, without considering the sap pathways, negatively impacts the conduction of xylem sap pathways in grapevines, both in terms of hydraulic efficiency and quantity of living and conducting tissues. However, the possible consequences of these reductions on grapevine physiological functions still need to be further investigated.
Reference
Claverie, M., Lecomte, P., Delorme, G., Dumot, V., Jacquet, O., & Cochard, H. (2023). Xylem water transport is influenced by age and winter pruning characteristics in grapevine (Vitis vinifera). OENO One, 57(3), 53–68. https://doi.org/10.20870/oeno-one.2023.57.3.7452
This abstract is republished with minor grammatical changes and headings inserted, as permitted by the Creative Commons License of Oeno One: https://creativecommons.org/licenses/by/4.0/
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