Vpliv izbranih talnih in reliefnih parametrov vinogradov v Vipavski dolini na sestavo grozdja in vina sorte 'Merlot' (Vitis vinifera L.)

Mihelčič, Alenka (avtor), Lisjak, Klemen (mentor), Vrščaj, Borut (komentor)

Vinogradi na terasah predstavljajo pomembno kulturno dediščino. Zaradi visokih stroškov vzdrževanja, pomanjkanja strokovnih delavcev ter podnebnih sprememb smo želeli preučiti vpliv nagiba gojenja trt na terasah na kakovost vina in grozdja. V letih 2019 in 2020 se je na relativno majhnem območju s podobnimi mezoklimatskimi razmerami grozdje ter vino s teras in iz dolin razlikovalo. Ravninski vinogradi na dolinskem dnu in vinogradi na terasah so se razlikovali v talnih profilih ter morfologiji tal. Tla na terasah so vsebovala do 90 % skeleta, tla vinogradov dolin pa so bila neskeletna. V obeh letih so bile trte s teras v večjem sušnem stresu kot trte iz dolin. Trte teras so imele manjšo maso (2019: –48 %; 2020: –34 %) in število grozdov (2019: –31 %; 2020: –17 %), maso jagod (2019: –24 %; 2020: –9 %), manj pridelka (2019: –49 %; 2020: –33 %) ter večje razmerje med kožicami (2019: +78 %; 2020: +22 %) in pečkami (2019: +70 %; 2020: +25 %) ter pulpo. Temnejša barva pečk grozdja s teras je nakazovala na večjo fenolno zrelost. Vina s teras so imela v obeh letih večjo vsebnost skupnih polifenolov (2019: +12 %; 2020: +24 %), antocianinov (2019: +24 %; 2020: +67 %) in proantocianidinov (PAs; 2019: +37 %; 2020: +30 %) ter so bila senzorično bolje ocenjena (2019: +51 %; 2020: +74 %) kot vina iz vinogradov z dolin. V letu 2019 so imela vina manj prodelfinidinov (–14 %) in bila bolj galoilirana (+26 %). Vina s teras so vsebovala več višjih alkoholov ter manj estrov. Sveže kožice grozdja s teras so v obeh letih vsebovale več antocianinov in skupnih polifenolov, suhe kožice dolinskih vinogradov pa več nizkomolekularnih PAs ter so bile v letu 2019 bolj galoilirane ter v letu 2020 vsebovale več prodelfinidinov. Pečke grozdja teras so bile bolj galoilirane ter v letu 2019 vsebovale več skupnih polifenolov, PAs in nizkomolekularnih PAs. Pod enakimi eksperimentalnimi razmerami, kot so datum vzorčenja, standardizacija vinogradniških parametrov, so imela vina, pridelana na vinogradih s teras, boljši fenolni potencial in bila senzorično prepoznana kot boljša v primerjavi z vini ravnin. Razumevanje vpliva tal in rastišča na kakovost grozdja in vina je ključnega pomena za določanje najprimernejših vinogradniških leg vina merlot.

• Jezik: Slovenski jezik
• Ključne besede: 'Merlot', tla, fliš, vodni potencial trt, grozdje, jagodne kožice, grozdne pečke, vino, senzorična analiza, polifenoli
• Vrsta gradiva: Doktorsko delo/naloga
• Tipologija: 2.08 - Doktorska disertacija
• Organizacija: BF - Biotehniška fakulteta
• Založnik: [A. Mihelčič]
• Leto izida: 2023
• PID: 20.500.12556/RUL-153290
• UDK: 634.8+663.2:543.2/.9
• COBISS.SI-ID: 180322819
• Datum objave v RUL: 21.12.2023

Sekundarni jezik

• Jezik: Angleški jezik
• Naslov: Effect of selected soil and relief vineyards parameters on grape and wine composition of 'Merlot' (Vitis vinifera L.) in Vipava Valley

Izvleček

Terraced vineyards hold cultural significance. Given high maintenance expenses, skilled labor scarcity, and climate shifts, we studied how terrace slope impacts wine and grape quality. In 2019 and 2020, grapes and wine from terraces and valleys differed in a relatively small area with similar mesoclimatic characteristics. Non–terraced vineyards in the valley floor and vineyards on terraces differed in soil profile and soil morphology. The soil on the terraces comprised as much as 90% skeleton, whereas the valley vineyards had a non–skeletal soil composition. In both years, the vines in the terraces were more affected by drought than the vines in the valleys. Grapes from all vineyards were harvested by hand and microvinified. The terrace vines had smaller, mass (2019: –48 %; 2020: –34 %) and number of clusters (2019: –31 %; 2020: –17 %), mass of berries (2019: –24 %; 2020: –9 %), lower yield (2019: –49 %; 2020: –33 %) and a higher ratio of skins (2019: +78 %; 2020: +22 %) to seeds (2019: +70 %; 2020: +25 %) and pulp. The darker color of the grapes from the terraces indicates a higher degree of phenol ripeness. In both years, the terrace wines had higher levels of total polyphenols (2019: +12 %; 2020: +24 %), anthocyanins (2019: +24 %; 2020: +67 %), and proanthocyanidins (PAs; 2019: +37 %; 2020: +30 %) and were sensory rated higher (2019: +51 %; 2020: +74 %) than the wines from the valley vineyards. In 2019, the wines had fewer prodelphinidins (–14 %) and were more galloylated (+26 %). The wines from the terraces contained more alcohol and less esters. Fresh grape skins from the terrace wines contained more anthocyanins and total polyphenols in both years, while dry skins from the valley wines contained more low–molecular weight PAs and were more galloylated in 2019 and contained more prodelphinidins in 2020. Grape skins from terraces were more galloylated in 2019 and contained more total polyphenols, PAs, and low–molecular weight PAs. Under the same experimental conditions (sampling date, standardization of vineyard parameters), wines from terraced vineyards exhibited better phenolic potential and were rated as better sensory than wines from non–terraced vineyards. Understanding the influence of soil and site on grape and wine quality is critical to determining the best vineyard sites suitable for Merlot wines.

• Ključne besede: 'Merlot', soil, flysch, vine water potential, grape, skins, seeds, wine, sensory analysis, polyphenols