Impact of mycorrhizal inoculation of ‘Monastrell’ grapevines grafted onto different conventional vs. newly breed rootstocks 

ine nitrogen deficiency can negatively influence the aroma profile and ageing potential of white wines. Canopy management can alter vine microclimate, affect the nitrogen availability and influence the response of leaf senescence. Increasing the nitrogen availability to vines can increase the Yeast Assimilable Nitrogen (YAN) levels in harvested fruit and wine. Studies show that foliar nitrogen and sulphur applications at véraison, on low YAN Sauvignon blanc grapes have an effect on the level of amino acids (Jreij et al. 2009) and on S-containing compounds such as glutathione and thiols (Lacroux et al. 2008), which in turn can influence the formation of major volatiles and the aroma profile of the wine.

Phenolic compounds are among the most important quality factors of wines. They contribute to the organoleptic characteristics of wine such as colour, astringency, and bitterness. Although tannins found in wine can come from microbial and oak sources, the main sources of polyphenols are skin and seed from grapes. Yet, the link between grape seed phenolic content and wine composition, or even the link between seed maturity stage and wine composition are poorly studied. This work describes and explains the seed tannins kinetics release in wine, but also the impact of seed maturity stage on seed tannins extractability.

The consequences of the global climate change in the vitiviniculture are revealed as a gap between phenolic and technological grape maturities, higher grape sugar concentration that leads to high wine alcohols levels, lower acidities and high pH values, among others. The unbalanced phenolic maturity caused in this scenario leads to harsh astringency and to instable colour of wines. Previous studies have reported that the addition of yeast mannoproteins (MPs) to wines may have positive effects on these two organoleptic properties due to their capability to interact with wine polyphenols [1]; however, studies about the effect of the pH on these interactions have not been carried out so far.

During wine production process high attention to the microbiological control from fermentation of the grape must to bottling is necessary. In fact, control of the indigenous microflora of the grape ensures correct fermentation activity of the inoculated starter, while control of the microorganisms in the finished wine is essential to prevent wine spoilage and to ensure the dominance of the desired bacteria when malolactic fermentation is required (Mas and Portillo, 2022).

Aims: The aim of the study was to investigate whether organic or biodynamic management have a long-term impact on 1) the microbial biomass and enzymatic activity in the soil, 2) the soil microbial community, 3) flying as well as soil living arthropods and associated fungi.