Unveiling the Grapevine Red Blotch Virus (GRBV) host-pathogen arms-race via multi-omics for enhanced viral defense 

Aims: Agroscope investigated the efficiency of nitrogen fertilization via foliar urea application at veraison with the aim of raising the YAN (yeast assimilable nitrogen) content in the musts. The observations were conducted on the white grapevine cultivar Doral (Chasselas x Chardonnay) in several pedoclimatic conditions of the Leman wine region, Switzerland, in the years 2012 and 2013. Knowing that the YAN in must plays a key role in wine quality, the aim was finding the main parameters affecting the final YAN level in order to better control them.

Biodiversity conservation and restoration are essential for guarantee the provision of ecosystem services associated to vineyard agroecosystem such as climate regulation trough carbon sequestration and control of pests and diseases. Most of published research dealing with the complexity of the vineyard agroecosystems emphasizes the necessity of innovative approaches, including the integration of information at different temporal and spatial scales and development of systemic analysis based on modelling. A biodiversity survey was conducted in the Franciacorta wine-growing area (Lombardy, Italy), one of the most important Italian wine-growing regions for sparkling wine production, considering a portion of the territory of 112 ha. The area was divided into several Environmental Units (EUs), defined as a whole vineyard or portion of vineyard homogenous in terms of four agronomic characteristics: planting year, planting density, cultivar, and training system. In each EU a set of compartments was identified and characterised by specific variables. The compartments are meteorology, morphology (altitude, slope, aspect, row orientation, and solar irradiance), ecological infrastructures and management. The landscape surrounding EU was also characterised in terms of land-use in a buffer zone of 500 m. For each component a specific methodology was identified and applied. Different statistical approaches were used to evaluate the method to integrate the information related to different compartments within the EU and related to the buffer zone. These approaches were also preliminarily evaluated for their ability to describe the contribution of biodiversity and landscape components to ecosystem services. This methodological exploration provides useful indication for the development of a fully systemic approach to structural and functional biodiversity in vineyard agroecosystems, contributing to promote a multifunctional perspective for the all wine-growing sector.

The qualitative and quantitative distribution of the phenolic compounds in red wines depends on cultivars features, on grapes maturation state, on grapes processing technology including must obtention, as well as on maceration-fermentation method (Margheri, 1981). The last two factors are responsible for the different phenolic composition of the wines produced from the same cultivar.

White wine protein haze can be prevented by removing the grape juice proteins, currently achieved by bentonite addition. To avoid wine volume loss and to minimizes aroma stripping, degrading haze-forming proteins in wine with proteases is a particularly interesting alternative to bentonite. In the present study, two fungal proteases treatments combined with different heating (50, 60, 72 °C) + refreshing steps, were applied on Gewürztraminer grape juice, and compared to bentonite treatments. The impact of these 19 treatments on the wine haze risks was determined by using two heat tests at 50 °C (heating during 30 to 120 min) and 80 °C (heating during 5 to 60 min). The protein contents and compositions were also estimated using the SDS-PAGE + densitometric integration techniques.

In the current climatic context, with milder winters leading to earlier budburst in most wine regions, vines are exposed to the risk of spring frosts for a longer period. Depending on the year, frost can lead to yield losses of between 20 and 100 %, jeopardizing the economic survival of wine estates. In addition, by destroying young shoots, spring frosts can impact the following season’s production, by reducing the number of canes available for pruning, for example. Late pruning is one method to combat spring frosts.