Mechanical Pruning and Soil Organic Amending in Two Terroirs. Effects on Wine Chemical Composition and Sensory Profile

Abstract:
The knowledge about the interaction between mechanical pruning and soil organic amending is still scarce. This study aimed to examine the effects of the interaction between these two practices on wine quality. Syrah grapes from two trial fields in Portugal subjected to two different pruning systems (mechanical pruning – MEC; hand spur pruning – MAN) and five different organic amendments treatments (control – Ctrl; biochar – Bioc; municipal solid waste compost – MSWC; cattle manure – Manure; sewage sludge – Sludge) were harvested and vinified for four years. Mechanical pruning significantly reduced wine alcoholic strength, pH and total anthocyanins. Mechanical pruning and organic amendments, tendentially reduced wine total phenols and tannin power, known as an estimation of the astringency potential of the wines. Tasters found low but significant differences in global appreciation with pruning system. Sludge tended to reduce wines global appreciation more than MSWC and Manure, while Bioc had no effect on tasters’ preference, when compared to Ctrl. There was strong relation between yield and tasters’ preference only above 6 and 8 kg/vine depending on the terroir. Mechanical pruning tendentially has significant effects on wine quality when yield raises above a certain level. Thus, with this pruning system, the choice of the organic amendment and its amount, must be done considering the destiny of the produced grapes. Impacts of the interaction of mechanical pruning with soil organic amending on wine quality are a novelty, to the best of our knowledge.
- Received April 2021.
- Revision received September 2021.
- Accepted September 2021.
- Published online December 2021
This is an open access article distributed under the CC BY license (https://creativecommons.org/licenses/by/4.0/).