GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 GiESCO 2019 9 Forcing vine regrowth in Vitis vinifera cv. Touriga nacional at Douro region

Forcing vine regrowth in Vitis vinifera cv. Touriga nacional at Douro region

Abstract

Context and purpose of the study ‐ Douro Region, characterized by a Mediterranean climate type and schist soils, is subjected to water and heat stresses conditions during summer. In some locations, the temperatures registered during berry maturation, lead to fruit ripen during warmer months, increasing the degradation of organic acids, tannins and phenolics that can negatively affect the quality of wines. Forcing vine regrowth is a new practice, being currently tested in Mediterranean countries, that aims to shift fruit ripening to cooler months of the year by pruning the plants after fruit set ‐ Crop Forcing (CF) ‐ removing all the leaves and bunches and leaving five buds per shoot, in order to reduce the negative effect of high temperatures during berry maturation on its quality.

Material and methods ‐ This work aims to study the effect of forcing vine regrowth in cv. ‘Touriga Nacional’ under Regulated Deficit Irrigation conditions, in vines irrigated with 30% of the evapotranspiration. Three modalities were established: vines with no forcing regrowth (Control ‐ CTRL), vines with CF set 15 days after fruit set (CF15) and plants with CF performed 30 days after fruit set (CF30). The effects on phenology, canopy development, berry development and fruit composition were assessed.

Results ‐ Plants subjected to CF15 were severely damaged after phenological stage of full bloom due to exceptional conditions to downy mildew (Plasmopara viticola) infections, boosted by the new phenological stages due to crop forcing. On the other hand, the crop forcing modality CF30 registered a delay of nearly two months in all phenological stages, since fruit set until harvest. Shorter internodes (50%) and lower leaf area (35%) were observed in CF30 when compared to the CTRL plants at ripening stage. The number of shoots at fruit set was also significantly different between the three treatments, with higher values in CF modalities and lower values in CTRL plants. In terms of yield, comparing CF30 th th (harvested in November, 27 ) and CRTL (harvest in October, 6 ), it was found that CF reduced the number of bunches (39%), the number of berries per bunch and the average berry weight (60%). Moreover, berries from the forced crop modalities (from grapes) had a pH slightly lower (3.35), higher titratable acidity (8.82 g/L) and lower ˚Brix (17.02˚Brix) when compared to CRTL, with pH values of 3.74, titratable acidity of 4.16 g/L and Brix of 23.93˚. Despite these results, further study should be carried out to evaluate the long‐term effects of CF and its applicability depending on the climatic conditions for each year.

DOI:

Publication date: June 22, 2020

Issue: GiESCO 2019

Type: Article

Authors

Inês L. CABRAL (1), Anabela CARNEIRO (1), Joana VALENTE (2), Fernando ALVES (2), Frank S. ROGERSON (2), Artur MOREIRA (2), Pedro LEAL da COSTA (2), Susana M.P. CARVALHO (1), Jorge QUEIROZ (1)

(1) GreenUPorto & DGAOT, Faculty of Sciences, University of Porto, Campus de Vairão, Rua da Agrária, 747, 4485-646 Vairão, Portugal
(2) Symington Family Estates, Travessa Barão de Forrester 86, 4431-901 Vila Nova de Gaia, Portugal 

Contact the author

Keywords

Douro region, crop forcing, grapevine, phenology, quality, yield

Tags

GiESCO 2019 | IVES Conference Series

Citation

Related articles…

Effect of malolactic fermentation in barrels or stainless steel tanks on wine composition. Influence of the barrel toasting

Ellagitannin, anthocyanin and woody volatile composition of Cabernet Sauvignon wines aged in oak barrels for 12 months was evaluated. Depending on the container where malolactic fermentation (MLF) was carried out, two wine modalities were investigated: wines with MLF carried out in stainless steel tanks and barrel-fermented wines. Three toasting methods (medium toast, MT; medium toast with watering, MTAA; noisette) were considered for ageing of each wine modality. Sensory analyses (triangle and rating tests) were also performed. Two-way ANOVA of the raw experimental data revealed that the toasting method and the container where MLF took place, as well as the interaction between both factors, have a significant influence (p < 0.05) on ellagitannin, anthocyanin and woody volatile profiles of Cabernet Sauvignon wines.

The effectiveness of proximal remote sensors in plant water status evaluation of grapevine

Extensive studies have been conducted on grapevine responses to water deficit, but these responses are difficult to generalise since numerous factors can influence the response(s), including genotype, developmental stage, soil, climate, and season.

Withering of the ‘Moscato giallo’ grapes under covered space

For the purpose of producing predicate wines in northern part of Croatia, grapes are traditionally left on the vine unpicked. However, grapes on the vine are exposed to unfavorable environmental conditions that affect rapid rotting and attacked by birds. To eliminate the mentioned risks, the grapes can be picked and placed in a protected space (loft, greenhouse, etc.) suitable for drying. This study presents the results of research on withering grapes of the ‘Moscato giallo’ variety in two tretment: sun drying (under covered terrace) and drying in the shade (loft). The following quality parameters were monitored: mass of grapes, sugar concentration, content of total acids, pH, content of organic acids.

IMPACT OF FINING WITH K-CARRAGEENAN, BENTONITE, AND CHITOSAN ON PROTEIN STABILITY AND MACROMOLECULAR COMPOUNDS OF ALBARIÑO WHITE WINE PRODUCED WITH AND WITHOUT PRE-FERMENTATIVE SKIN MACERATION

Pre-fermentative skin maceration is a technique used in white wine production to enhance varietal aroma, but it can increase protein concentration, leading to protein instability and haze formation [1]. To prevent protein instability, wine producers typically use fining agents such as bentonite, before wine bottling, which can negatively impact sensory characteristics and produce waste [2,3]. The aim of this study was to understand the impact of alternative techniques such as the application of polysaccharides (k-carrageenan and chitosan) on protein stability and on the wine macromolecular composition.

LC-MS based metabolomics discriminates premium from varietal chilean Cabernet Sauvignon cv. Wines

Aim of the study was to investigate the metabolomic differences between Chilean Cabernet Sauvignon wines, divided according to their quality in two main groups: “Varietal” and “Premium”, and to point out metabolites tentative markers of their chemical signature and sensorial quality. Initially, 150 (50 x 3 biological replicates) experimental wines were produced by the same semi-industrial process, which covered 8 different Chilean valleys. The wine classification made by experts, divided the wines into two major groups (“Varietal” and “Premium”) and four subgroups (two for each major group). All the samples were analyzed according to a robust LC-MS based untargeted work-flow (Arapitsas et al 2018), and the proposed minimum reporting standards for chemical analysis of the Metabolomics Standards Initiative (Sumner et al 2007)