GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 GiESCO 2019 9 Colored hail‐nets as a tool to improve vine water status: effects on leaf gas exchange and berry quality in Italia table grape

Colored hail‐nets as a tool to improve vine water status: effects on leaf gas exchange and berry quality in Italia table grape

Abstract

Context and purpose of the study ‐ Protecting table grape vineyards with white hail‐nets is a common practice in Southern Italy. Hail‐nets result in shading effects of 10‐20 %, depending on their density and type of weave, thus they act as a low shading nets and modify the vineyard microclimate. Darker nets are more opaque to solar radiation, increasing the shading effects. Colored nets have been introduced in horticultural crops aiming to alter the amount and composition of light available at canopy level, in order to getparticular light‐induced effects on microclimate, plant physiology, growth and production. Yellow and red nets are among the most studied. However, by now, results of different studies are not always consistent with each other. The present study aimed at assessing the performance of Italia table grape grapevine under yellow and red hail‐nets, with a particular interest to the chance of modulating the microenvironment to support the vine water status under the semi‐arid conditions of Southern Italy, evaluating also the effects exerted on the grape quality.

Material and methods ‐ The study was run in 2014 and 2015, in the BT province of Apulia region, on Italia covered with white, yellow and red nets, all having mesh of about 3×5 mm. PAR, air temperature and RH were monitored in warm hours of typical days of mid‐ and late‐ July and August. Leaf gas exchange and stem water potentials were measured. Leaf area was assessed ceptometrically. At harvest, berry fresh weight, skin color, juice total soluble solid concentration (TSS) and titratable acidity (TA), main skin and pulp phenol contents, and berry antioxidant activity (AA) were determined.

Results – Respect to the white net,the colored ones reduced the PAR available for canopy (especially the red net) and increased air temperature and RH (especially the yellow net). On average, they lowered the air VPD along the canopy profile by ~10% and improved the vine water status from 33 % (yellow net) to 38 % (red net). However, this improvement did not enhance the leaf gas exchange measured at maximum PAR 2 interception (~1450 ~mol/m /s); on the contrary, the leaf transpiration, and even more the net CO2 uptake, tent to be lowered by yellow net, but not, or at a little extent, by the red net. The leaf area did not change. According to literature, yellow color depresses the transmissivity of red and blue wavelengths, active on photoreceptors that stimulate stomata opening and PSII efficiency. At harvest, on average, the patterns of berry and bunch weight were similar to those of leaf gas exchange (especially to the transpiration one); the yellow component of the skin color decreased with both colored nets; the TSS/TA ratio increased. The skin phenol contents were lowered by the red net but not, or a very little extent, by the yellow one; the berry antioxidant activity progressively decreased passing from the white to the yellow and to the red net. In conclusion, under the trial conditions, the yellow and red hail‐nets did not influence the performance of Italia grapevine in univocal way. Some responses seemed more related to their low shading effects, while others to their spectrometric effects. They rose significantly the vine water status compared to the white net, but this improvement did not enhance other physiological parameters or any berry quality attributes.

 

DOI:

Publication date: June 22, 2020

Issue: GiESCO 2019

Type: Article

Authors

Laura de PALMA (1), Patrizio LIMOSANI (1), Vittorino NOVELLO (2)

(1) University of FOGGIA-SAFE, Via Napoli 25, I-71122, Foggia, Italy
(2) University of Turin-DiSAFA, Largo Braccini 2, I-10095, Grugliasco (TO), Italy

Contact the author

Keywords

Grapevine, Microenvironment, Ecophysiology, Maturity indices, Phenol contents, Berry antioxidant activity

Tags

GiESCO 2019 | IVES Conference Series

Citation

Related articles…

‘Cabernet Sauvignon’ (Vitis vinifera L.) berry skin flavonol and anthocyanin composition is affected by trellis systems and applied water amounts

Trellis systems are selected in wine grape vineyards to mainly maximize vineyard yield and maintain berry quality. This study was conducted in 2020 and 2021 to evaluate six commonly utilized trellis systems including a vertical shoot positioning (VSP), two relaxed VSPs (VSP60 and VSP80), a single high wire (SH), a high quadrilateral (HQ), and a guyot (GY), combined with three levels of irrigation regimes based on different crop evapotranspiration (ETc) replacements, including a 25% ETc, 50% ETc, and 100% ETc. The results indicated SH yielded the most fruits and accumulated the most total soluble solids (TSS) at harvest in 2020, however, it showed the lowest TSS in the second season. In 2020, SH and HQ showed higher concentrations in most of the anthocyanin derivatives compared to the VSPs. Similar comparisons were noticed in 2021 as well. SH and HQ also accumulated more flavonols in both years compared to other trellis systems. Overall, this study provides information on the efficacy of trellis systems on grapevine yield and berry flavonoid accumulation in a currently warming climate.

Bioclimatic shifts and land use options for Viticulture in Portugal

Land use, plays a relevant role in the climatic system. It endows means for agriculture practices thus contributing to the food supply. Since climate and land are closely intertwined through multiple interface processes, climate change may lead to significant impacts in land use. In this study, 1-km observational gridded datasets are used to assess changes in the Köppen–Geiger and Worldwide Bioclimatic (WBCS)

Terroir traceability in grapes, musts and wine: results of research on Gewürztraminer and Sauvignon Blanc grape varieties in northern Italy

In the study of terroir, a separate analysis of its many component factors can be of great help in accurately identifying a vineyard’s natural elements that impact wine quality and typicity. This research used a dedicated pluri-disciplinary approach to investigate the ecological characteristics, including geology and geographical features, of 14 vineyards that produce Gewürztraminer and Sauvignon Blanc cultivars in the alpine Alto Adige DOC wine region. Both the geopedological method using Vineyards Geological Identity (VGI) and the new Solar Radiaton Identity (SRI) topoclimatic classification method were used to provide analytical measurements and qualitative/quantitative characterisations. In addition, wide-ranging targeted and untargeted oenological and chemical analyses were carried out on grapes, musts and wines to correlate the soils’ geomineral and physical conditions with the biochemical properties of their fruits and wines. The research identified strong correlations between vineyard geo-identity and wine biofingerprint, confirming a mineral traceability of strontium rubidium ratio and some minerals distinctive to the local geology, such as K, Ca, Ag, Ba and Mn.  The study also discovered that particular geomineral and physical soil conditions of the studied vineyards are related to the different amount of amino acids, primary varietal aromas and polyphenols found in grapes, musts and wines. The research confirmed that winemaking technologies support oenological quality, although in some cases, human practices can overpower certain characteristic elements in wine, erasing the typical imprint left by the vineyards’ natural terroir, which becomes less traceable. Terroir abiotic ecological factors and vineyard identity can be classified in detail using the new VGI and SRI analysis methods to discover interrelationships between geo-pedological and topoclimatic conditions that impact wine quality. These methods are also helpful in identifying which ecological elements are exclusive to a particular vineyard or wine sub-region.

From a local to an international scale: sensory benchmarking of PDO wines. Quincy and Reuilly PDO wines (Sauvignon blanc) as a case study (France)

In a collective marketing strategy, the Protected Designation of Origin (PDO) can be used as a quality indicator. To highlight terroir specificities, it is useful to know how the wines are positioned on the local, national or international market from a sensory point of view. This is especially true for a comparison of varietal wines (e.g. Sauvignon blanc). We focus on the case of two closed Loire Valley PDO (France): Quincy and Reuilly. Three distinct tastings were organized. Firstly, at the local level comparing the 2 PDO (11 and 9 wines, 17 professional assessors); secondly at a regional level adding 3 closed PDO: Menetou-Salon, Sancerre and Pouilly-Fumé (3 wines per PDO, 16 assessors) and thirdly at an international level comparing these 5 PDO with Sauvignon Blanc wines coming from South Africa, New Zealand and Chile (1 to 3 wines per PDO, 19 assessors). All the wines were from the 2019 vintage and were considered to have a traditional elaboration process without contact with oak. A sensory descriptive analysis was performed using an aroma wheel allowing to combine a Check-All-That-Apply methodology, often used in sensory benchmarking, with a hierarchical structuration of the attributes. The aim is to facilitate data acquisition in a professional context without common training, to consider the hierarchical relationships among the attributes during the data analysis and to be able to characterize wines with a large range of sensorial variability. We use univariate, multivariate and clustering analyses. Similarities and differences between Quincy and Reuilly PDO wines and other Sauvignon blanc wines were identified. Specific attributes can distinguish the two PDO and different proximities exist with other local PDO, while clear differences were observed compared to international wines. Our study contributes to propose and discuss a method to do a wine sensory benchmarking highlighting sensory specificities linked to origin.

Inhibition of Oenococcus oeni during alcoholic fermentation by a selected Lactiplantibacillus plantarum strain

The use of selected cultures of the species Lactiplantibacillus plantarum in Oenology has grown in prominence in recent years. While initial applications of this species centred very much around malolactic fermentation (MLF), there is strong evidence to show that certain strains can be harnessed for their bio-protective effects. Unwanted spontaneous MLF during alcoholic fermentation (AF), driven by rogue Oenococcus oeni, is a winemaking deviation that is very difficult to manage when it occurs. This work set out to determine the efficacy of one particular strain of Lactiplantibacillus plantarum(Viniflora® NoVA™ Protect), against this problem in Cabernet Sauvignon must. The work was carried out at commercial scale and in a winery environment and compared the bio-protective culture with the more traditional approach of reducing must pH by the addition of tartaric acid. The combination of both was also investigated. The concentration of both Oenococcus oeni and Lactiplantibacillus plantarum was determined using qPCR. The adventitious Oenococcus oeni showed the most growth during AF in the control wine, whereas in the wines treated with Lactiplantibacillus plantarum a bacteriostatic effect against this species was observed. This effect was comparable to the wines treated with tartaric acid. This has particular commercial relevance for controlling the flora in musts with high pH, or when the addition of tartaric acid is either not permitted or is prohibitive for other reasons.