Vpliv razlistanja na količino in kakovost grozdja žlahtne vinske trte (Vitis vinifera L.) sorte 'Istrska malvazija'

Grdina, Mateja (author), Rusjan, Denis (mentor)

V magistrski nalogi smo preučevali vpliv razlistanja ter rezanja šparonov med zorenjem jagod na količino in kakovost grozdja sorte 'Istrska malvazija'. Bločni poskus smo izvedli leta 2013 v vinogradu v Izoli v lasti Vinakoper d.o.o., ki je zajemal štiri obravnavanja, in sicer razlistanje v coni grozdja takoj po cvetenju (R1), razlistanje mladih listov med drugo in tretjo žico med zorenjem grozdja (R2), rez šparona oziroma namensko dvojno zorenje grozdja (DMR) in kontrola (K). Grozdje smo med dozorevanjem vzorčili štirikrat, razen pri R1, saj je bila trgatev 10 dni pred ostalimi obravnavanji zaradi prej dosežene tehnološke zrelosti. Med obravnavanji ni bilo značilnih razlik v rastnem potencialu ter v masi grozdja (3,5-3,9 kg/trto), značilno najmanjšo maso 100-tih jagod smo izmerili pri R1 (216,2±5,2 g) ter DMR (230,8±3,2 g). Med parametri kakovosti grozdja ob trgatvi so se med obravnavanji pokazale značilne razlike samo v vsebnosti jabolčne in skupnih kislin. Značilno največje vsebnosti smo izmerili pri R1, 3,73±0,42 g/l jabolčne in 9,39±1,20 g/l skupnih kislin. Tudi v vinu R1 smo izmerili značilno največ skupnih kislin (6,5±0,2 g/l), mlečne (0,3±0,02 g/l) in jabolčne kisline (2,9±0,1 g/l). Značilne razlike so se med obravnavanji pokazale tudi v vsebnosti nekaterih posameznih fenolov v kožici jagod in vinu, predvsem med R1 in DMR, pri slednjem smo v povprečju izmerili največje vsebnosti katehina (11,8 mg/l), kvercetin-3-rutinozida (9,9 mg/l), kamferol-3-galaktozida (0,7 mg/l) in izoramnetin-3-glukozida (5,9 mg/l). Izpostaviti velja, da v vsebnosti skupnih fenolov, izmerjenih spektrofotometrično, se med obravnavanji niso pokazale razlike. Za pridobitev boljšega vpogleda na odziv sorte na navedene vinogradniške prakse, bi bilo potrebno poskus izvesti vsaj tri leta, predvsem zaradi vremenskih razlik med leti.

• Language: Slovenian
• Keywords: vinska trta, razlistanje, količina, kakovost, grozdje, Vitis vinifera
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: BF - Biotechnical Faculty
• Publisher: [M. Grdina]
• Year: 2019
• PID: 20.500.12556/RUL-113064
• UDC: 634.8:631.542.25:631.559(043.2)
• COBISS.SI-ID: 9362809
• Publication date in RUL: 01.12.2019

Secondary language

• Language: English
• Title: Impact of defoliation on grape quantity and quality of grapevine (Vitis vinifera L.) 'Istrska malvazija' variety

Abstract

In the Master thesis we studied the impact of the defoliation and cane cutting during grape ripening on the quality and quantity of the variety ‘Istrska malvazija’. In 2013, the block trial was performed in a vineyard in Izola owned by Vinakoper d.o.o. The trial included four treatments: defoliation in the grape area immediately after flowering (R1), defoliation of young leaves above grape area during ripening (R2), cane cutting (double maturation raisonnée; DMR) and the control (K). The grape was sampled four times during ripening, except at R1, grape of which was harvested 10 days before of other treatments. There were no significant differences among treatments in growth potential and yield (3.5-3.9 kg/vine), but significantly minimal weight of 100 berries was measured at R1 (216.2±5.2 g) and DMR (230.8±3.2 g). Among the qualitative parameters of grapes at the harvest, significant differences were observed in the content of malic and total acids. The significantly highest content was measured at R1 reaching 3.73±0.42 g/L of malic acid and 9.39±1.20 g/L of total acidity. The significantly highest content of total acidity (6.5±0.2 g/L), lactic acid (0.30±0.02 g/L) and malic acid (2.9±0.1 g/L) were also found in R1 wines. Most significant differences in phenolics contents were found between R1 and DMR. In the berry skin and wine at DMR, the highest contents of catechin (11.8 mg/L), quercetin-3-rutinoside (9.9 mg/L), kaempferol-3-galactoside (0.7 mg/L) and isoramnetin-3-glucoside (5.9 mg/L) were measured. It should be noted that the content of total phenols measured spectrophotometrically did not show differences among treatments. In order to gain a better insight into the impact of studied practices on the variety, the trial should be conducted for at least three years, mainly due to the weather differences among years.

• Keywords: vine, defoliation, quantity, quality, grapes, Vitis vinifera