Impact of red blotch disease on Cabernet Sauvignon and Merlot grape and wine composition and wine sensory attributes

Grapevine leaf removal (LR) in the cluster area is typically done between fruit set and cluster closure to create an unfavorable microclimate for fungal diseases, such as Botrytis cinerea and powdery mildew. Grape growers are now turning their attention to pre-flowering LR, which has additional benefits under certain conditions. When applied before flowering, LR strongly affects fruit set and thus the number of berries per cluster. It is therefore a good yield control tool, replacing time-consuming manual cluster thinning (Poni et al. 2006). It also improves berry structure, that is, skin thickness, skin-to-pulp ratio, and berry composition (total soluble solids, titratable acidity, and polyphenols) (Palliotti et al. 2012; Komm and Moyer 2015). By exacerbating competition for assimilates between reproductive and vegetative organs, pre-flowering LR also poses some risks. Excessive yield loss at the same year’s harvest due to a too low fruit set rate is the main concern: intensive pre-flowering LR (100% of the cluster area) can induce up to 50% yield loss in potted vines (Poni et al. 2005). Other parameters, such as cool climatic conditions during flowering, also affect fruit set rate and make it difficult to predict potential yield at harvest. Repeated and overly intensive preflowering LR can have repercussions over time and induce a decline in bud fruiting and plant vigor (Risco et al. 2014).

Grapevines interact with the climate (aboveground) and the soil (belowground), affecting the characteristics of winegrapes produced. These interactions are impacted by climate change, the erosion of biodiversity, and losses of soil organic matter (SOM).

For a long time, cool climate grapevine breeding has striven for early ripening cultivars to adapt to the former climate conditions.

Plant water status of grapevine plays a critical role in affecting berry and final wine chemical composition. The environmental variabilities existing in vineyard system have significant impacts on plant water status, but it is challenging to individualize environmental factors from the temporal and spatial variabilities in vineyard. Therefore, there is need to monitor the ecophysical variation through utilizing precision viticulture tools in order to minimize the separation in berry composition. This study aims at delineating vineyard into different management zones based on plant water status explained by soil texture, and utilize differential harvest to equilibrate the final berry and wine composition.

Contribution Foam is the characteristic that differentiates sparkling wines from still wines, being the first sensory attribute that tasters and consumers perceive and that determines the final quality of sparkling wines [1]. The foaming properties mainly depend on the chemical composition of wines [2-3], and different factors involved in wine composition will have an effect on foam quality. In Spain, the sparkling wine market focuses on the production of white and rosé sparkling wine, with very low production of red sparkling wines. However, this type of wines is elaborated in countries like Australia, South-Africa, Argentina, Italy or Portugal, with a great acceptance by consumers. No studies on the foaming characteristics of red sparkling wines have been found.