Viticultural and enological strategies for the prevention of Botrytis cinerea- induced quality losses

In 2019, we have planted the red variety Manseng Noir, as it has been shown that it is the only sister of the Tannat grape. Tannat was introduced to Uruguay in 1870 from the south-western regions of France.

Row orientation and canopy management are essential for high quality grapevine production. Microclimatic conditions of the leaves and fruits can be influenced by the canopy geometry. Remote sensing is a very promising tool to describe vegetative growth and physiological behavior of vineyards. However, the correlation between remotely sensed data and in situ field measurements has been described scarcely in the scientific literature so far. The aim of the study was to correlate remotely sensed data obtained with Unmanned Aerial Vehicle (UAV) with in situ field measurements to describe canopy structure.

The irrigation water management in the vineyard is a crucial aspect to obtain sustainable quality production over time. Previous studies have set the water requirements to be applied in the vineyard at 30 % of the reference evapotranspiration (ET0), although there are no studies that settle the effects of the frequency of irrigation application on red varieties in Spain. The present study contemplates the application of deficit irrigation (30 % ET0) applying a weekly dose in a single irrigation (T07) or in two irrigation events (T03) per week. The study has been carried out in 2021-2022 with four red varieties in different Spanish wine regions: Garnacha Tinta (Badajoz), Tempranillo (Valladolid), Syrah (Albacete) and Mencía (Lugo). The effects of irrigation frequency on must volatile composition have been evaluated through GC-MS.

Red grape pomace can be an important source of polysaccharides, but currently they are little studied and even less with viable and environmental extraction processes (green extraction). These green techniques must be able to break the cell wall so that the compounds contained in the cells, including polysaccharides, are released and can have a great influence on extraction yields, the chemical structure of polysaccharides and applications in wines. Amongst the emerging green techniques most applied to the extraction of bioactive compounds, such as polysaccharides, high-power ultrasound (US) and enzyme-assisted extraction stand out.

Mousy off-flavor is one of the defects of microbial origin in wine. It is described as a particularly unpleasant defect reminiscent of rodent urine (a “dirty mouse cage”), and grilled foods such as popcorn, rice, crackers, and bread crust. Prior to the 2010s, mousiness was very uncommon but it has been becoming more frequent in recent years. It is often associated with an increase in pH as well as certain oenological practices, which tend to significantly decrease the use of sulfur dioxide.