Water deficit and salinity are increasingly affecting the viticulture and wine industry. These two stresses are intimately related; understanding the physiological and metabolic responses of grapevines to water deficit, salinity and combined stress is critical for developing strategies to mitigate the nega- tive impacts of these stresses on wine grape production. These strategies can include selecting more tolerant grapevine cultivars and graft combinations, improving irrigation management, and using soil amendments to reduce the effects of salinity. For this purpose, understanding the response of grape- vine metabolism to altered water balance and salinity is of pivotal importance.

During postharvest management, the metabolism of fruits remains active and continuous physico-chemical changes occur. Ozone treatment has an elicitor effect on secondary metabolites and the treatment conditions can influence the grape response to the stress (Bellincontro et al., 2017; Botondi et al., 2015). Regarding volatile organic compounds (VOCs), previous studies showed that ozone treatment during postharvest dehydration induces the biosynthesis of terpenes in Moscato bianco grapes (Río Segade et al., 2017). It is well known that grape VOCs greatly influence the organoleptic properties of wines, particularly terpenes in aromatic varieties.

1,1,6-Trimethyl-1,2-dihydronaphthalene (TDN) is a controversial aroma component found in Riesling wines. It belongs to the family of C13-norisoprenoids and is mainly associated with kerosene/petrol notes. TDN can add complexity to the wine aroma at medium – low concentrations and deteriorate the wine bouquet when its content is high. No TDN aromas are usually perceived in young Riesling wines, but they can appear after several years of aging due to the gradual formation of TDN. Management of TDN in Riesling wines is an actual task, since global warming can promote formation of this compound and compromise the aromatic composition of wine. Therefore, the aim of the current work was, firstly, to study the sensory particularities of TDN in Riesling wine at various concentrations. Secondly, to investigate the ability of bottle closures to absorb (scalp) TDN from Riesling wine under various storage conditions. These studies also include the comparative assessment of our findings with previously published data. METHODS: sensory analysis, GC-MS (SBSE), HPLC,1H-NMR and other methods related to the synthesis and determination of TDN. RESULTS: First of all, the method of the synthesis of highly purified TDN (95% and 99.5%) was optimized [1].

The Texas High Plains AVA is one of eight officially recognized wine regions in Texas, established in 1993. Six local wineries, including the second-largest in Texas, are supported by approximately 50 vineyards, which are also major suppliers of grapes to Texas wineries outside the region.

Developing technologies that help vines survive and produce in quantity and quality within current times is mandatory. In this sense, in the 2021/2022 agricultural harvest, the influence of the foliar application of seaweed – Laminaria japonica was studied, aiming at productivity and quality of the must in the ‘Merlot’ grape. In the city of “Santana do Livramento”, “Rio Grande do Sul” (RS), Brazil; in a 15-year-old commercial vineyard of ‘Merlot’ clone ENTAV-INRA® 347, grafted onto ‘SO4’ rootstock, the following treatments were applied on 6 occasions: No treatment (control) and; Foliar application of Laminaria japonica seaweed (commercial product: Exal (ALAS), 2 kg ha-1).