Utjecaj različitih termina djelomične defolijacije na polifenolni sastav grožđa sorte 'Merlot'

master's thesis

• Title (english): Influence of different timings of partial defoliation on polyphenol composition of grapes of the 'Merlot' variety
• Author: Petra Rajić
• Mentor: Marko Karoglan (mentor)
• Committee member: Marko Karoglan (predsjednik povjerenstva)
• Committee member: Bernard Kozina (član povjerenstva)
• Committee member: Ana Jeromel (član povjerenstva)
• Committee member: Marina Anić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Agriculture; (Department of Viticulture and Enology); Zagreb
• Defense date and country: 2020-09-10, Croatia
• Scientific / art field, discipline and subdiscipline: BIOTECHNICAL SCIENCES; Agronomy

Abstract

Djelomična defolijacija u zoni grozdova jedan je od najčešćih ampelotehničkih zahvata korištenih u proizvodnji grožđa u cilju poboljšanja mikroklimata loze te povećanja kvalitete grožđa. Zahvat djelomične defolijacije proveden na početku šare grožđa do sada je bio uobičajen za kontinentalnu Hrvatsku zbog hladnijih i vlažnijih klimatskih prilika, ali zbog povećanja temperature zraka u posljednjim godinama nužno je preispitati različite termine provođenja djelomične defolijacije u spomenutom području. Za očekivati je da će raniji termini provođenja djelomične defolijacije utjecati na smanjenje prinosa te na povećanje koncentracije šećera i polifenolnih spojeva u grožđu sorte 'Merlot'. Cilj rada je utvrditi utjecaj termina provođenja djelomične defolijacije na prinos, osnovni kemijski sastav te sadržaj pojedinačnih polifenolnih spojeva u grožđu sorte 'Merlot'. Istraživanje je provedeno na VVP Jazbina, na sorti Merlot 2019. godine. Zahvat djelomične defolijacije obavljen je u četiri termina, gdje su se sa svake mladice skidala 4 bazalna lista, dok je peti tretman kontrola. Termini provedbe djelomične defolijacije su: prije cvatnje i oplodnje, neposredno nakon cvatnje i oplodnje, u fazi zatvaranja grozdova i u šari. Pokus je postavljen po slučajnom bloknom rasporedu u tri repeticije. Eksperimentalni blok čine tri susjedna trsa, što znači da je svaka varijanta zastupljena s devet trsova vinove loze. U vinogradu je, u trenutku pune zrelosti, svaki trs pobran zasebno, te je utvrđena prosječna masa grozda i prinos po trsu. Od svakog ponavljanja uzet je uzorak mošta iz kojeg je određen sadržaj šećera i ukupne kiseline prema O.I.V-u (2001). Od svakog ponavljanja uzet je i uzorak od 100 bobica, kojima je odvojena kožica za određivanje pojedinačnih polifenola primjenom metode tekućinske kromatografije.

Abstract (english)

Partial defoliation in the grape zone is one of the most common ampelotechnical procedures used in grape production in order to improve the microclimate of the vine and increase the quality of grapes. The partial defoliation procedure carried out at the beginning of the grape season has so far been common for continental Croatia due to colder and wetter climatic conditions, but due to the increase in air temperature in recent years it is necessary to review the different dates of conducting partial defoliation in the mentioned area. Earlier timings of partial defoliation are expected to affect the decrease in yield and the increase in the concentration of sugar and polyphenol compounds in the grapes of the 'Merlot' variety. The aim of the work is to determine the influence of partial defoliation on yield, the basic chemical composition and the concentration of individual polyphenol compounds in the grape of the 'Merlot' variety. The research was conducted at VVP Jazbina, on the Merlot variety, 2019. The partial defoliation procedure was performed in four timings, where four basal leaves were removed from each treatment, while the fifth treatment was controls. The timings of partial defoliation were: before flowering, immediately after flowering, when the grapes were pea-size and at the begining of veraison. The experiment was set up on Randomized Complete Block Design ─ RCBD in three repetitions. The experimental block consists of three adjacent vines, which means that each treatment is represented with nine vines. In the vineyard, at a time of full maturity, each vine was picked separately, and the average mass of bunches and yield per vine was determined. From each repetition, a sample of the must was taken from which the sugar content and total acidity was determined according to O.I.V (2001). A sample of 100 berries was also taken from each repetition, which separated the grape skin to determine individual polyphenols using the method of liquid chromatography.

• Keywords: djelomična defolijacija; prinos; polifenolni sastav; Merlot
• Keywords (english): partial defoliation; yield; polyphenol composition; Merlo
• Language: croatian
• URN:NBN: urn:nbn:hr:204:253403
• Study programme: Title: Horticulture; Study programme type: university; Study level: graduate; Academic / professional title: magistar/ magistra inženjer/inženjerka hortikulture (magistar/ magistra inženjer/inženjerka hortikulture)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Access restricted to students and staff of home institution
• Created on: 2020-10-08 11:40:30