Conduite en Lys: résultats pendant la formation du système avec le cépage Loureiro dans la région des “Vinhos Verdes”

Climate change impacts water availability for agriculture, notably in semi-arid regions like South Africa, necessitating research on cultivar and rootstock adaptability to water constraints. To evaluate the performance (vegetative and reproductive) of different Chenin Blanc-rootstock combinations to the two water regimes, a field experiment was established in a model vineyard at Stellenbosch University, South Africa. Chenin Blanc vines grafted onto four different rootstocks (110Richter, 99Richter, 1103Paulsen and US 8-7) were planted in 2020. The vines are managed under two contrasting water conditions – dryland and irrigated (industry norm).

Sulphites are by far the most widely used additive in the wine industry. In relation to health, the interaction of sulphites with the gut microbiota has not been addressed so far. Following the consumption of wine and other sulphite-containing foods, the gastrointestinal tract and the microbiome are one of the first barriers that these compounds face in the human organism. In this study, we used a previously validated gastrointestinal digestion model (SIMGI®) [1,2] to evaluate the effect of intestinal digestion of wine sulphites on the gut microbiome.

Protein instability in wines is challenging, and despite many efforts to find satisfactory alternatives to bentonite, both in terms of stability and quality, the solutions are limited in the wine industry.

Grapevines are continually wounded throughout their cultivation especially during winter pruning. Grapevines respond to wounding by occluding xylem vessels with gels or tyloses to limit pathogen attack and dehydration of the tissues. Although the production of xylem vessel occlusions has been studied in grapevine, to date we have no knowledge of whether different genotypes respond differently. The objective of this study was to characterize the genetic variation in xylem vessel occulsions in five different scion genotypes pruned at different dates.

The current climate changes are directly threatening the balance of the vineyard at harvest time. The maturation period of the grapes is shifted to the middle of the summer, at a time when radiation and air temperature are at their maximum. In this context, the implementation of corrective practices becomes problematic. Unfortunately, our knowledge of the climate effect on the quality of different grape varieties remains very incomplete to guide these choices. During the Innovine project, original experiments were carried out on Syrah to study the combined effects of normal or high air temperature and varying degrees of exposure of the berries to the sun. Berries subjected to these different conditions were sampled and analyzed throughout the maturation period. Several quality characteristics were determined, including anthocyanin content. The objective of the experiments was to investigate which climatic determinants were most important for anthocyanin accumulation in the berries. Temperature and irradiance data, observed over time with a very thin discretization step, are called functional data in statistics. We developed the procedure SpiceFP (Sparse and Structured Procedure to Identify Combined Effects of Functional Predictors) to explain the variations of a scalar response variable (a grape berry quality variable for example) by two or three functional predictors (as temperature and irradiance) in a context of joint influence of these predictors. Particular attention was paid to the interpretability of the results. Analysis of the data using SpiceFP identified a negative impact of morning combinations of low irradiance (lower than about 100 μmol m−2 s−1 or 45 μmol m−2 s−1 depending on the advanced-delayed state of the berries) and high temperature (higher than 25oC). A slight difference associated with overnight temperature occurred between these effects identified in the morning.