Effect of pre-fermentative strategies on the polysaccharide composition of must and white wines

With the aim of producing premium wines, it is admitted that moderate environmental stresses may contribute to the accumulation of compounds of interest in grapes. However the ongoing climate change, with the appearance of more limiting conditions of production is a major concern for the wine industry economic. Will it be possible to maintain the vineyards in place, to preserve the current grape varieties and how should we anticipate the adaptation measures to ensure the sustainability of vineyards? In this context, the question of the responses and adaptation of grapevine to abiotic stresses becomes a major scientific issue to tackle. An abiotic stress can be defined as the effect of a specific factor of the physico-chemical environment of the plants (temperature, availability of water and minerals, light, etc.) which reduces growth, and for a crop such as the vine, the yield, the composition of the fruits and the sustainability of the plants. Water stress is in many minds, but a systemic vision is essential for at least two reasons. The first reason is that in natural environments, a single factor is rarely limiting, and plants have to deal with a combination of constraints, as for example heat and drought, both in time and at a given time. The second reason is that plants, including grapevine, have central mechanisms of stress responses, as redox regulatory pathways, that play an important role in adaptation and survival. Here we will review the most recent studies dealing with this issue to provide a better understanding of the grapevine responses to a combination of environmental constraints and of the underlying regulatory pathways, which may be very helpful to design more adapted solutions to cope with climate change.

For several years, the development of computer resources, and in particular of Geographic Information Systems, have allowed the emergence of a new approach to the analysis and characterization of wine-growing areas (Morlat, 1989; Laville, 1990). These methods, which make it possible to identify homogeneous areas or units of terroir, are based on crossing, statistical analysis (in particular Principal Component Analysis: PCA) and the integration of parameters describing the natural environment in which develop the vine.

Sforzato di Valtellina DOCG is a special reinforced red wine produced using withered Nebbiolo grapes. The withering process takes place in traditional rooms under natural environmental conditions; it starts immediately after the harvest and ends not before the 1st December of the same year. The process can be performed with different bunch placements that can influence the grapes features.The purpose of the study is to compare the effect on grape physico-chemical parameters for four withering bunch placement systems: hanged clusters (HC), plastic crates (CT), breathable mesh fabric on wooden frames panels (MF), and reed mats (RM). For all the systems studied, the withering length was two months at a temperature between 6 and 19 °C and a relative humidity of 41-88%.

Depuis le millésime 2002, une étude est menée sur la diversité de la flore fongique de parcelles du cépage chenin, situées essentiellement sur les appellations de Vouvray et Montlouis ; deux appellations séparées par le fleuve nommé la Loire. Les parcelles se situent dans des conditions pédoclimatiques différentes, qui se retrouvent au travers des suivis de maturité et l’état sanitaire.

In the O Ribeiro Denomination of Origin, there is a winemaking tradition of growing vines under a high-density plantation framework (8,920 vines/ha) and maintaining its vegetative cycle under rainfed conditions.
Currently, viticulture is advancing to plantation frames in which the density is considered medium (5,555 vines/ha), thus allowing mechanized work to be carried out for vineyard management operations. Although, the application of irrigation applied proportionally to the needs of the vegetative cycle of the vine, is a factor that increasingly helps a good development of the vine compared to the summer period, with increasingly uncertain weather forecasts.