Freeze-thaw temperature oscillations promote increased differential gene expression during grapevine bud dormancy

Vine water status is one of the most influential factors in grape vigor, yield, and quality (Ojeda et al., 2002; Guilpart et al., 2014). Severe water deficits during the first stage of crop development (bud break to fruit set) impact yield in the current year and the following year. While during grape ripening, water availability impacts berry size, grape composition, and health status. Therefore, a correct assessment of plant water status allows for proper water management with an impact on grape yield and composition (McClymont et al, 2012; Pereyra et al., 2022).

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).

During a three-year period, the vineyards of the Carnuntum wine district are investigated for their terroir characteristics. The interdisciplinary study is aimed at the description of the physiogeographic

NIR spectroscopy has widely been tested in viticulture as powerful alternative to traditional analytical methods in the field of quality evaluation. NIR instruments have been used for assessing must and wine quality features in several works, but little information regarding their application on whole berries for polyphenol determination is available.

Industry and regulatory agencies have developed regulations to ensure authenticity and compliance with wine composition limits. However, this can be truncated by the absence of simple and robust analytical methodologies, uninfluenced by the environment, different oenological techniques and cultural practices. Genetic fingerprinting is the most powerful tool for unequivocal varietal identification; it is not affected by the environment or agronomic practices; however, its usefulness in musts and wines has been controversial and there is currently no routine certification of varietal origin based on DNA analysis.