Effect of ultraviolet B radiation on pathogenic molds of grapes

Grapevines are grown mainly as grafts worldwide, but the rootstocks most commonly used were selected between the late 19th and early 20th centuries and are based on reduced genetic diversity[1]. In the context of climate change, it is indeed urgent to diversify the range of rootstocks with genotypes much more adapted to drier environments, than the existing ones[2]. The aim of this study was to evaluate the potential of new genetic resources for grapevine rootstock breeding programs. For this purpose, 12 American and Asian wild Vitis species (3 to 5 accessions per species = 50 accessions) were evaluated for their rooting ability and drought response.

In a context of sustainable agriculture, “agroecological immunity” is an emerging concept to reduce the use of chemical pesticides to protect crops against pathogens. This alternative strategy aims to combine different levers including the use of “bio”solutions. These include biocontrol products, some of which being plant defense elicitors, as well as products authorized in organic farming such as copper or sulfur. In vineyards, depending on climate conditions, powdery and downy mildews can be devastating diseases.

SO2 play a major role in wine stability and evolution during its aging and storage. Winemaking without SO2 is a big challenge for the winemakers since the lack of SO2 affects directly the wine chemical evolution such as the aromas compounds as well as the phenolic compounds. During the red wine aging, phenolic compounds such as anthocyanin, responsible of the red wine colour, and tannins, responsible of the mouthfeel organoleptic properties of wine, evolved quickly from the winemaking process to aging [1]. A lot of new interaction and molecules occurred lead by oxygen[2] thus the lack of SO2 will induce wine properties changes. Nowadays, the phenolic composition of the wine without added SO2 have not been clearly reported.

The impact of climate change is noticeable in the present weather, making water scarcity the most immediate mediator reducing the performance and viability of crops, including grapevine (Vitis vinifera L.). The present study developed a system (hardware, firmware, and software) for the determination of plant water use through changes in weight through a period. The aim is to measure the differences in grapevine water consumption in response to climate change (+4oC and 700 ppm) under controlled conditions. The results reveal a correlation between daily plant consumption rates and reference evapotranspiration (ETo).

The main objective of the work was to develop a simple, robust and selective analytical tool that allows predicting the authenticity of Tempranillo wines from DOCa Rioja. The techniques of voltammetry and absorbance-transmission and fluorescence excitation emission matrix (A-TEEM) spectroscopy have been applied in combination with machine learning (ML) algorithms to classify red wines from DOCa Rioja according to region (Alavesa, Alta or Oriental) and category (young, crianza or reserva).