Effect of partial defoliation on chemical composition of Cabernet sauvignon grapes

master's thesis

• Title: Utjecaj djelomične defolijacije na kemijski sastav grožđa sorte "Cabernet sauvignon"
• Author: Josip Prekratić
• Mentor: Marko Karoglan (mentor)
• Committee member: Marko Karoglan (predsjednik povjerenstva)
• Committee member: Bernard Kozina (član povjerenstva)
• Committee member: Ana Jeromel (član povjerenstva)
• Granter: University of Zagreb; Faculty of Agriculture; (Department of Viticulture and Enology); Zagreb
• Defense date and country: 2017-07-12, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Agronomy; Viticulture and Enology

Abstract

Djelomična defolijacija je jedan od najčešće primjenjivanih zahvata zelenog reza. Defolijacijom u zoni grožđa mijenjamo mikroklimu trsa, dolazi do boljeg osvjetljenja grožđa te boljeg strujanje zraka, no smanjuje se lisna masa, a u grozdovima izloženima suncu može doći do prevelikog zagrijavanja. Cilj ovog istraživanja bio je utvrditi utjecaj djelomične defolijacije na kemijski sastav grožđa sorte Cabernet sauvignon, berbe 2015. godine. Pokus je proveden tako da su četiri bazalna lista sa svake mladice pokusnih trsova uklonjena u četiri različita termina: prije cvatnje i oplodnje, neposredno nakon cvatnje i oplodnje, u fazi zatvaranja grozdova te u šari. Dobivenim rezultatima je utvrđeno da je djelomična defolijacija u svim terminima utjecala na povećanje ukupne kiselosti, smanjenje pH i povećanje sadržaj ukupnih polifenola u grožđu. Defolijacije u terminima prije cvatnje i oplodnje te u fazi zatvaranja grozdova su utjecale na povećanje sadržaja šećera, dok defolijacije u terminima neposredno nakon cvatnje i oplodnje te u šari nisu utjecale na sadržaj šećera.

Abstract (english)

Partial defoliation is one of the most commonly used management practice in modern vineyards. Leaf removal in the fruit zone will change canopy microclimate, increase cluster exposure to light and air circulation. However, partial defoliation results in leaf area reduction and can cause excessive berry heating. The aim of this research was to determine how partial defoliation affects chemical composition of 2015 Cabernet Sauvignon grapes. Partial defoliation was performed by removal of four basal leaves from each shoot of experimental vines in four different stages: before flowering, immediately after flowering, at pea-size and at verasion. Partial defoliation in all stages contributed to higher total acidity, lower pH and higher phenolic concentration. Defoliation in stages before flowering and pea-size contributed to higher soluble solids, while defoliation in other two stages didn't affected on soluble solids.

• Keywords: djelomična defolijacija; kemijski sastav grožđa; polifenoli; ukupna kiselost; šećeri
• Keywords (english): partial defoliation; chemical composition; polyphenols; total acidity; soluble solids
• Language: croatian
• URN:NBN: urn:nbn:hr:204:954360
• Study programme: Title: Hortikultura; Study programme type: sveučilišni; Study level: diplomski; Academic / professional title: magistar/ magistra inženjer/inženjerka hortikulture (magistar/ magistra inženjer/inženjerka hortikulture)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Restricted access
• Created on: 2017-07-24 12:49:09