The dynamics of accumulation of sugar, acids, total polyphenols and anthocyanins in grapes Cv.Frankovka (Vitis vinifera L.) in the vineyards Feričanci

Abstract

Na kemijski sastav grožđanog soka utječu brojni čimbenici, a neki od njih su zrelost, sorta, područje u kojem raste te godina berbe. Faktori koji utječu na određivanje optimalnog termina berbe su sadržaj šećera i kiselina u grožđu, a kod proizvodnje crvenih vina, kakvo se proizvodi od sorte Frankovka, bitan faktor je i količina polifenola i antocijana u grožđu. Prorjeđivanje grozdova je bitan ampelotehnički zahvat u suvremenoj vinogradarskoj proizvodnji. U ovom radu smo pratili dinamiku akumulacije šećera, kiselina, polifenola i antocijana u grožđu cv. Frankovka (Vitis vinifera L.), uzgojenom na vinogorju Feričanci, s ciljem utvrđivanja utjecaja prorjeđivanja grozdova na kvalitetu grožđa. Ukupno je provedeno 10 uzorkovanja, svaki u razmaku od 7 dana, počevši od 18.07.2011. do 26.09.2011. godine. Rezidba je obavljena na način da su ostavljena dva reznika i lucanj sa osam pupova. Postavljene su tri varijante, tako da u prvoj varijanti nisu uklanjani grozdovi, u drugoj je sa svake mladice uklonjen po jedan grozd a u trećoj je ostavljano samo šest grozdova po trsu. Izmjerene su značajne razlike između pojedinih varijanataThere are many factors affecting chemical content of grape juice, some of which are ripeness, variety, area in which it is grown and the year of the harvest. Optimal harvesting period is affecting by the level of sugar and acid in grapes. When it comes to red wines, such as Frankovka, there is also the amount of tannin and anthocyanins in grapes to be considered. An important viticultural practices in modern wine industry is pruning of the bunches of the grapes. This paper depicts our following of the dynamics of accumulation of sugars, acid and overall poliphenols and antocyanins on Frankovka grapes (Vitis vinifera L.) in Feričanci wine region. The purpose of this paper is to determine how pruning bunches of grapes affects the quality of the grapes. We have conducted 10 pruning procedures, each 7 days apart, starting from 18.07.2011. to 26.09.2011. Vine pruning was done in a way that two canes and one spur with eight buds has been maintained. We have conducted 3 experiments. In first experiment no grape bunches have been removed. In second experiment we have removed one grape bunch from each sprout. In the third experiment there were only six bunches of grapes per vine left. Significant differences have been noted