Confronto di 11 cloni di Xinomavro in relazione al processo di maturazione delle bacche, mosto e vino finale

The objective of this work was to assess and compare eleven clones of Xinomavro cultivar, E1, 37, 35, 28, 36, 22, 19, E30, E10 and one that was used as a reference clone, called STANDARD (STD). There is a lot of information regarding clonal variation between grapevine varieties, but research concerning especially the Xinomavro cultivar are very limited, while none has focused on the comparison of these eleven clones in Amyndeon appellation PDO. The experiment was carried out in Amyndeon region, Northwestern of Macedonia, Greece in Alpha Estate during the grape growing period 2020. The clones were planted in 2016 in a single experimental block. The data gathered were analyzed, using the R statistical software, for the analysis of variance (ANOVA) and Tukey’s test in order to test for significant differences between the clones. During the grape ripening period the evolution of physicochemical characteristics, phenolic compounds and anthocyanins were evaluated. Parameters like seed weight, berry weight and diameter and cluster compactness were also measured and differences were observed among the candidate clones. Furthermore, the duration of phenological stages was also determined, fruit set period and the completion of veraison of each clone. During grape harvest, yield components were determined for all the clones in order to assess their final quantity. Differences were observed in the phenolic composition between the clones. During ripening, the evolution of physicochemical parameters was different among the clones and, as a consequence, the wines produced from these clones showed significant differences, as well. Glories Method showed differences between the clones concerning the phenolic concentration. During their maturation process, samples were taken from the field with the aim of assessing the dates of harvest. The results showed that physicochemical characteristics present significant differences, especially for the pH and sugar levels. Yield also varied between the clones, especially for 37, E1 and E10. During the winemaking process, measurements of the density and temperature were taken twice per day for 10 days. After the completion of the alcoholic fermentation, the wines went under Malolactic Fermentation and then bottling took place. Clone 37 presented the most qualitative traits, together with E1 clone would make them ideal for aged wine production, while 37 is also suitable for sweet wine production. High sugar level, high acidity, and high phenolics are important characteristics for dry red aged wine production. On the other hand clones E30, 35, 31, 36 and 28 found to match the profile of a young red wine. Fruity and fresh, not high alcohol level, good acidity and low-medium phenolics. For the sparkling wine production, clones 19 and the STANDARD fit for base wines. High acidity, low in phenolic and alcoholic strength. Clones 19 and E10 are pertinent for the rose wine production. Aromatic wines, high acidity with low to medium phenolic composition and low color. Lastly, clone 22 even though it presents low alcohol content, compared to the other clones, it suits for blending purposes with the aim of color enhancement and also could provide structure to wines.