Vpliv različnih tehnoloških praks na količino in kakovost grozdja in vina žlahtne vinske trte (Vitis vinifera L.) sorte 'Pokalca'

Ribolica, Luka (author), Rusjan, Denis (mentor)

'Pokalca' je v Goriških brdih tradicionalna in obenem v Sloveniji manj znana sorta, ki daje vina z vonjem, ki spominja na slive in rdeče sadeže. Na okusu je vino pikantno, s priokusom, ki spominja na poper. Pri pridelavi grozdja sorte 'Pokalca' se pridelovalci pogosto srečujejo z zelo veliko rodnostjo trt, velikimi podolgovatimi grozdi, na katerih jagode neenakomerno zorijo, kar se odraža v slabši kakovosti grozdja in vina. V Brdih smo izpeljali dvoletno raziskavo na sorti 'Pokalca', pri kateri smo ugotavljali vpliv (i) obročkanja rozg in nanosa bora, (ii) prikrajševanja in (iii) redčenja grozdov na dozorevanje in kakovost grozdja in vina. V obeh letih (2018 in 2019) se je pri obravnavanjih redčenje in prikrajševanje grozdov značilno povečala masa grozdov (200 g–310 g) in vsebnosti topne suhe snovi (21,9–22,6 °Brix), medtem ko smo pri obročkanju v letu 2018 zabeležili značilno večjo vsebnost skupnih kislin (4,81 g/l), ter jabolčne (1,66 g/l) in citronske kisline (0,45 g/l). Jagode na prikrajšanih in redčenih grozdih so imele značilno večji CIRG-indeks, kljub temu, da se vsebnosti posameznih antocianinov (od 0,95 mg/l peonidin-3-glukozida pa vse do 237,7 mg/l malvidin-3-glukozida) niso bistveno razlikovale od jagod preostalih obravnavanj. Prav tako so bila vina, pridelana iz grozdja s trt, kjer je bilo opravljeno redčenje in prikrajševanje, boljše senzorično ocenjena in kot taka potrošniku bolj všečna. Imela so večjo vsebnost dejanskega alkohola (12,9–13,1 vol. %), skupnega ekstrakta (26,9–27,5 g/l) in manjšo vsebnost skupnih kislin (4,7–5,0 g/l). Na podlagi pridobljenih rezultatov se lahko zaključi, da redčenje in prikrajševanje grozdov značilno vpliva na boljšo kemijsko sestavo in senzorično kakovost grozdja in vina sorte 'Pokalca'.

• Language: Slovenian
• Keywords: vinska trta, prikrajševanje grozdov, obročkanje, redčenje, grozdje, vino, kakovost, 'Pokalca'
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: BF - Biotechnical Faculty
• Year: 2025
• PID: 20.500.12556/RUL-170771
• COBISS.SI-ID: 242859779
• Publication date in RUL: 16.07.2025

Secondary language

• Language: English
• Title: Impact of different technological practices on the grape and wine quantity and quality of grapevine (Vitis vinifera L.) 'Pokalca' variety

Abstract

'Pokalca’ is a traditional but less known variety in Slovenia. It is native to the Goriška brda region, where it produces medium-bodied wines with a violet-blue hue and an aroma reminiscent of plums and red fruits. On the palate, the wine has a spicy character with a peppery aftertaste. When cultivating the 'Pokalca' grape variety, growers often encounter very high yields, with large, elongated grape clusters and uneven ripening of the berries, which results in lower quality grapes and wine. In Brda, we conducted a two-year study on the ‘Pokalca’ variety, examine the impact of (i) girdling and boron application, (ii) selective cluster thinning and (iii) cluster thinning on the ripening and quality of ‘Pokalca’ grapes and wine. In both years (2018 and 2019), treatments with selective cluster thinning and cluster thinning resulted in a significant increase in cluster mass (200-310 g) and total soluble solids (TSS) content (21.9-22.6 °Brix). In 2018, gridling resulted in a significantly higher total acidity (4.81 g/l) as well as a higher content of malic acid (1.66 g/l) and citric acid (0.45 g/l). The berries from selective cluster thinning and thinned clusters had a significantly higher CIRG index, although there was no significant difference in the content of individual anthocyanins (between 0.95 mg/l peonidin-3-glucoside and 237.7 mg/l malvidin-3-glucoside) between the treatments. In addition, the wines produced from thinned or selective thinned grapes were rated better in terms of sensory evaluation and were perceived as more likeable by consumers. The wines had a higher alcohol content (12.9-13.1 % vol.), a higher total dry extract (26.9-27.5 g/l) and a lower total acidity (4.7-5.0 g/l). The results obtained lead to the conclusion that cluster thinning and selective cluster thinning significantly improve the chemical and sensory evaluation of the grapes and the wines of the 'Pokalca' variety.

• Keywords: grapevine, thinning, girdling, cluster thinning, grape, wine, quality, 'Pokalca'