A four-year comparison of the assessment of anthocyanins in berries (Vitis vinifera L. cv. Pinot noir) using a non-invasive chlorophyll fluorescence method
The aim of this study was to find a method assessing non-destructively the maturity and anthocyanin concentration of Vitis vinifera L. cv. Pinot noir providing a tool to better estimate the variability within a vineyard. Besides the CIELa*b* using the visible reflectance spectrum and hyperspectral imaging (combining short- wave-infrared (SWIR) images and vis/NIR images), a hand-held optical sensor (Multiplex3® (Force-A, Orsay, France) based on chlorophyll fluorescence screening showed promising results. Indeed, a relationship between the Multiplex3 index and the anthocyanin concentration was already shown.
Adressing vineyard variability by targeted berry sorting
Variability of grape quality traits is encountered in vineyards between individual vines, between clusters within a single vine, and between berries of single bunches. While precision viticulture addresses systematic geologic and microclimatic variance within a vineyard, the within-vine and within-bunch variability are inaccessible to targeted management or selective harvesting.
The regulation of the grapevine berry transcriptome by temperature is dependent on the circadian cycle
High throughput transcriptomic studies (microarray, RNA-seq) are powerful tools to decipher changes in gene expression during fruit development and to target candidate genes involved in the plant response to environmental stresses. However, the rapid RNA turnover rate constitutes a major drawback in transcriptomic studies upon introducing sensitivity to environmental and trophic changes within one day.
Cluster microclimate (light and thermal) is a key point of grape maturity in Mediterranean semiarid conditions
Sunlight and microclimate inside the clusters zone are key factors in berry development and must composition. In Mediterranean conditions (warm and dry climate), the use of porous systems can help plants establish a better leaf distribution inside the clusters area, providing more space and enhancing certain physiological processes, both in leaves (photosynthesis, ventilation, transpiration) and berries (growth and maturation).
Are wild grapes interesting? Analysis of phenolic compounds and antioxydative properties of grape berry skins in samplings of Vitis vinifera silvestris and Vitis vinifera sativa
An analysis of total polyphenols, anthocyanins, phenolic acids, stilbenes and antioxydative properties of grape berries of Vitis vinifera silvestris referred to Vitis vinifera sativa – Pinot noir and Syrah – revealed an interesting potential in some autochthonous wild vines, in particular the first one which was authenticated in the Ariège county of Pyrénées.
Deciphering the impacts of berry irradiation and temperature on flavonoid composition in grapevine (Vitis vinifera cv. Syrah)
Environmental factors affect grape production by impacting carbon acquisition, source-sink relationships, berry ripening processes and the resultant wines. At the fruit level, it is generally accepted that high irradiance enhances the synthesis of anthocyanins and flavonols.
Impact of climate on tartric acid metabolism of Ugni blanc berries: comparing of two vintages with climatic conditions contrasting
The acid component of berries is an essential criterion for the quality and preservation of distillation wines of Cognac. It must be high enough to protect wine during the storage phase, awaiting distillation. Climate change observed in the Cognac region for several years impact on the acid component of the Ugni-Blanc berries with a slight decrease in malic and tartaric acid content.
Evolution of grapevine (Vitis vinifera L.) berry heterogeneity during ripening
The timing of grape picking is a critical point for to production of high quality wines. Berry growth and major solutes are routinely measured on a mix of randomly sampled berries, in order to characterize the advancement of ripening at the vineyard scale, and optimize the date of harvest with respect to the specific conditions of the millesime.
Effect of sunlight exposure on berry composition and aromatic profile of Vitis vinifera L. cv. “Yellow Muscat”
Muscat grape cultivars are known for the strong aromatic properties they confer to wines. However, the strength of the aroma depends on multiple variables including variety, environmental conditions during the growth season and cultural practices.
DEXiPM-Grapevine©: A multicriteria assessment tool of the sustainability for grapevine farming systems
The development of innovative farming systems to reach new goals of agricultural sustainability needs new methods for efficiency assessment. DEXiPM-Grapevine© is a multicriteria assessment tool for overall sustainability of grapevine farming systems adapted from DEXiPM arable crops (Pelzer et al, 2012). DEXiPM-Grapevine© was implemented during the European PURE Project 2012- 2015 (Integrated Pest Management (IPM) solutions in agriculture) in order to assess and compare various innovative grapevine systems.
Assessment of new viticulture systems under a set of high constraints
Combining drastic reduction of inputs and high sensitivity of vine to pathogens implies re-designing viticulture production systems. The newly designed systems then need to be assessed to be sure that they are sustainable and can be implemented by wine growers.
Berry temperature as affected by canopy structure/trellis system/pruning method in grapevine cv. Syrah
The aim of the work was to evaluate the effect of different canopy structures, deriving from two trellis structures and three pruning methods, on berry internal temperature, juice composition and main skin phenol traits of cv Syrah grape. The work was done at the ARC Experiment Farm in Robertson, South Africa.
Using canopy management and plant growth regulators to enhance fruit maturity of Cabernet franc under Southern Oregon conditions
Wine grapes have shown tremendous promise crop in Southern Oregon. The grape growers and winemakers have expressed their interest in more research on optimization of canopy management practices or introducing new technology to improve fruit quality and mitigate seasonal variation. The aim of this study was to assess the effect of canopy management practices (shoot and crop thinning) and plant growth regulators (PGR) on vine performance and fruit quality. The experiment had a split block design with three replicates.
Influence of leaf removal on berry thermal efficiency for anthocyanin accumulation
The aim of this work was to analyse the effects of leaf removal on Touriga Nacional berry temperature and consequent thermal efficiency for anthocyanins biosynthesis. The field experiment was located at Dão Wine Research Station, Nelas, Portugal in an adult vineyard planted with North-South oriented rows, with the red grape variety Touriga Nacional grafted on 110R rootstock. The vines were trained on a vertical shoot positioning, spur-pruned on a bilateral Royat cordon system and deficit irrigated (50% ETc).
Four years trial of early defoliation and its effects on yield and quality cv. Loureiro in vinhos Verdes region
The aim of this study was to evaluate if early defoliation can be an alternative to bunch thinning in limiting yield and improving quality in grapes of the white cultivar Loureiro (Vitis vinifera L.), grafted onto 1103P. The field trial had been set up in a commercial vineyard in Vinhos Verdes Region (Northwest of Portugal, 41º 48’ 53” N, 8º 24’ 42” W).
Minimal pruning as a tool to increase the anthocyanin: sugars ratio in grapes
Minimal pruning (MP) is considered as a possible alternative technology in vineyards in the face of global warming. In order to evaluate its effect on grapes cultivated in warm areas, a long-term study about minimal pruning on Tempranillo (Vitis vinifera L.) was conducted in Badarán (La Rioja, Spain). For every vintage between 1999 and 2013, grapes from minimal-pruned vines and the vines of control treatment were harvested at the same time; Yield and total soluble solids (TSS, oBrix) were determined.
Minimal pruning increases the concentration of aromatic precursors in viognier grapes
Aromatic composition of grapes is essential to wine quality. A study was conducted over four years, under Mediterranean conditions in southern France, to assess the impact of different training systems on aromatic precursors in fruit of Viognier B. grapevines. Two training systems [vertical shoot positioning (VSP) and minimal pruning (MP)] were investigated during the 2010, 2011, 2013 and 2014 seasons.
Esca of grapevine and training system
Esca is currently, in France or even in Europe, the most concern grapevine disease. This trunk decline disease affects the longevity of vineyards. It is caused by the development of large inner necrosis in the grapevine wood associated with a wide fungal procession whose key players have already been identified. However the predisposing factors that favour the development of inner necrosis are still unknown or underestimated.
Effects of different “dwarf-training” patterns on the berry quality of Vitis vinifera cv. Cabernet Gernischet (Carmenère) in the Ningxia
In order to reduce the cost of grape-burying in late autumn (ground covering vines under the row for winter, and being pulled out in the inter-row for the growing season) for preventing frost injury in the Ningxia region, 12 years old vines of Vitis vinifera cv. Cabernet Gernischet (Carmenère) are used as test material in this experiment. They are cultivated in a particular way to reduce vigour and maintain the fruiting zone close to the ground, thus making the burying in late autumn easier.
Comparison of vineyard nitrogen application practices and winery nitrogen management
The timing of Nitrogen (N) application is critical for altering vine development, the N directed to berries and reserves. Stress on the vine, or nutrient and irrigation management, might give the accumulated reserves a critical role during grape maturation in the following season, influencing berry composition and wine quality. The aim of this project was to clarify the link between N input and reserves on fruit and wine composition under different environmental conditions.