Knowledge has been accumulated on the impact of microclimate, in particular berry temperature and irradiation, for a wide range of red varieties. However, little research has been dedicated on the effects of the same factors on the quality of white grape varieties.

The Tannat grape, native to the foothills of the Pyrenees in France, is known for producing wines with intense colour, exceptional tannic structure, and remarkable aging potential. These distinctive characteristics are attributed to its unique genome, making Tannat one of the grape varieties with the highest tannins concentration.

AIM: In a recent study, it was determined that the mid-ripening period is the most suitable for the application of methyl jasmonate (MeJ), benzothiadiazole BTH and MeJ+BTH on Monastrell grapes, to favor maximum accumulation of phenolic compounds at the time of harvest. However, the increase in the anthocyanin content of

Irrigation is an important practice to influence vine quality, especially in Mediterranean regions, characterized by hot summers and severe droughts during the growing season. This study focused on deficit irrigation regime influence on amino acids composition of Monastrell grapevines under semiarid conditions (Albacete, Southeastern of Spain). In 2019, two treatments were applied: non-irrigation (NI) and regulated deficit irrigation (RDI), watered at 30% of the estimated crop evapotranspiration from fruit set to onset of veraison. Grape amino acids content was analyzed by HPLC. Berries from non-irrigated vines showed higher concentration of several amino acids, such as tryptophan (73%), arginine (70%), lysine (36%), isoleucine (27%), and leucine (21%), compared to RDI grapes. Arginine is, together with ammonium ion, the principal nitrogen source for yeasts during the alcoholic fermentation; while isoleucine, tryptophan, and leucine are precursors of fermentative volatile compounds, key compounds for wine quality. Moreover, NI treatment increased in a 14% the total amino acids content in grapes compared to RDI treatment. The reported effects might be because yield was 70% higher in RDI vines than in the NI ones and, therefore, the sink demand was increased in the irrigated vines. In addition, NI vines suffered more severe water stress and it is known that the amino acids synthesis and accumulation can be influenced by the plant response to stress. According to the results, the irrigation regime showed effect on amino acids concentration in Monastrell grapes under semiarid conditions. Grapes from non-irrigated vines showed a higher content of several amino acids relevant to the fermentative process and to the wine aroma compounds formation. It is demonstrated that the final content of nitrogen-related components in grapes is influenced by the irrigation regime. The convenience of the irrigation strategy to suggest will depend on the desired wine style and the target yield levels.

AIM: The current loss of genetic grapevine diversity is mainly due to the reduced number of varieties used for making wine. A way of preserved endangered varieties is the establishment of germplasm banks.