Towards the definition of a terroir of grape dehydration for the production of ‘Passito’ wines in Valpolicella (Italy)

The vineyard world is faced to a lot of fungal diseases. Grapevine Trunk Diseases (GTD) are some of the major. After exhibiting chronical foliar symptoms, grapevines can die by apoplexy within only few days. A range species of fungi was described to be associated with the apparition of early symptoms of GTD. It is well known that ozone dissolved into water is a powerful disinfectant with no remanence. The main goal of this study was to test the efficiency of this process on different fungal species associated with GTD in vitro and in planta conditions.

Many high quality Open Source scientific applications have been available for a long time. Some of them have proved to be particularly useful for carrying out the usual activities involved in viticultural research projects, such as statistical analyses (including spatial analyses), GIS work, database management (possibly integrated with statistical and spatial analysis) and even “low-level” often highly time-consuming activities (e.g. repetitive task on text files).

The use of next-generation sequencing (NGS) has helped understand microbial genetics in oenology. Current studies mainly focus on barcoded amplicon NGS but not shotgun sequencing, which is useful for functional analyses. Since the high percentage of grapevine DNA conceals the microbial DNA in must, the majority of sequencing data is wasted in bioinformatic analyses. Here we present capture depletion of grapevine whole genome DNA.

A gradual decline in vineyards has been observed over the past twenty years worldwide. This might be explained by the climate change, practices change or the increase of dieback diseases. To increase the longevity of vines, we studied the impact of different pruning strategies in four adult and four young vineyards located in France and Spain. In France, vineyards were planted with Cabernet franc on 3309C while Spanish trials were planted with Tempranillo grafted on 110R. Vegetative expression, yield, quality of berries and wood vessels conductivity were measured. The distribution of vegetative expression, yield and berry composition between primary and secondary vegetation were quantified. Finally, tomography was used to evaluate the implication of the treatments on sap flows.
First results show that i) the respectful pruning leads to an increase of 30 to 50% more secondary shoots than the aggressive pruning in France and between 15 and 20% in Spain, ii) there is no major effect on the yield over the first two years following the implementation of the new pruning practices, although the proportion of clusters from suckers is higher on the respectful pruning method. On young vines, the development of the trunk according to a respectful pruning leads to a loss of harvest 2 years after planting. This is due to the removal, on the future trunk, of the green suckers which carrying bunches. This operation carried out in spring rather than during winter pruning, would promote a better leaf / fruit balance when the plant comes into production, and could lead to better hydraulic conduction in the vessels of the trunk. Maintaining these trials for several years will provide more robust data to assess the impact of these practices on the vines over the long term.

Pulsed electric fields (pef) technology holds significant promise for the agrifood industry, considering the capacity of inducing cell electroporation, due to the disruption of cellular membranes. Pef-induced permeabilization is dependent of the chosen treatment protocol (i.e. Pulse shape, electrical field strength, specific energy) and of the matrix’s characteristics (i.e. Cell radii and size, ph, electrical conductivity).