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…

DNA-free editing to improve stress resilience of wine grape genotypes recalcitrant-to-regeneration

Wine viticulture, being firmly linked to the vine-terroir relationship, has always encountered significant bottlenecks to genetic innovation. Nonetheless, the development of new breeding strategies leading to the selection of stress resilient genotypes is urgent, especially in viticulture, where it would allow reducing the use of chemical treatments adopted to control fungal diseases. Genome editing represents an extremely promising breeding technique. Unfortunately, the well-known recalcitrance of several wine grape cultivars to in vitro regeneration strongly limits the exploitation of this approach, which to our knowledge has so far been developed on table grape genotypes with high regeneration potential.

Influence of SO2 and Zinc on the formation of volatile aldehydes during alcoholic fermentation

Laboratório de Análisis del Aroma y Enologia (LAAE). Department of Analytical Chemistry, Faculty of Sciences, Universidad de Zaragoza, 50009, Zaragoza, Spain, During alcoholic fermentation, fusel (or Strecker) aldehydes are intermediates in the amino acid catabolism to form fusel alcohols following the Ehrlich Pathway (1). One of the main enzymes involved in this pathway is Alcohol Dehydrogenase (ADH), whose activity is highly strain dependent and determines the rate of conversion of aldehydes into fusel alcohols (2). This enzyme has a Zn2+ catalytic binding site, which suggests that the must Zn2+ levels will most likely influence the rate of reduction of aldehydes into alcohols. On the other hand, SO2 is commonly used in winemaking for its antiseptic and antioxidant properties.

Effect of regulated deficit irrigation regime on amino acids content of Monastrell (Vitis vinifera L.) grapes

Irrigation is an important practice to influence vine quality, especially in Mediterranean regions, characterized by hot summers and severe droughts during the growing season. This study focused on deficit irrigation regime influence on amino acids composition of Monastrell grapevines under semiarid conditions (Albacete, Southeastern of Spain). In 2019, two treatments were applied: non-irrigation (NI) and regulated deficit irrigation (RDI), watered at 30% of the estimated crop evapotranspiration from fruit set to onset of veraison. Grape amino acids content was analyzed by HPLC. Berries from non-irrigated vines showed higher concentration of several amino acids, such as tryptophan (73%), arginine (70%), lysine (36%), isoleucine (27%), and leucine (21%), compared to RDI grapes. Arginine is, together with ammonium ion, the principal nitrogen source for yeasts during the alcoholic fermentation; while isoleucine, tryptophan, and leucine are precursors of fermentative volatile compounds, key compounds for wine quality. Moreover, NI treatment increased in a 14% the total amino acids content in grapes compared to RDI treatment. The reported effects might be because yield was 70% higher in RDI vines than in the NI ones and, therefore, the sink demand was increased in the irrigated vines. In addition, NI vines suffered more severe water stress and it is known that the amino acids synthesis and accumulation can be influenced by the plant response to stress. According to the results, the irrigation regime showed effect on amino acids concentration in Monastrell grapes under semiarid conditions. Grapes from non-irrigated vines showed a higher content of several amino acids relevant to the fermentative process and to the wine aroma compounds formation. It is demonstrated that the final content of nitrogen-related components in grapes is influenced by the irrigation regime. The convenience of the irrigation strategy to suggest will depend on the desired wine style and the target yield levels.

Using remotely sensed (UAV) and in situ field measurements to describe grapevine canopy characteristics

Row orientation and canopy management are essential for high quality grapevine production. Microclimatic conditions of the leaves and fruits can be influenced by the canopy geometry. Remote sensing is a very promising tool to describe vegetative growth and physiological behavior of vineyards. However, the correlation between remotely sensed data and in situ field measurements has been described scarcely in the scientific literature so far. The aim of the study was to correlate remotely sensed data obtained with Unmanned Aerial Vehicle (UAV) with in situ field measurements to describe canopy structure.

Caratterizzazione varietale della CV. Vranac del Montenegro: primi risultati

Questo studio ha permesso di raccogliere alcune informazioni sul profilo chimico della cultivar Vranac coltivata in Montenegro. L’uva ha mostrato di raggiungere un buon accumulo zuccherino