Effects of early leaf removal on volatile compounds concentrations in Cabernet Sauvignon wines from the Ilok vineyards

The aim of this two year study was to evaluate effects of basal leaf removal before blooming on volatile composition of Cabernet Sauvignon wines in the Ilok vineyards (eastern Croatia). During two consecutive vintages (2013, 2014), two different treatments of basal leaf removal were applied: removal of 3 and 6 leaves, and control without leaf removal. Volatile compounds of resulting wines were identified and quantified by gas chromatography coupled with mass spectrometry. Organic acids and higher alcohols remained unaffected by treatments of early defoliation wine, except acetic acid and 2-methyl-6-hepten-1-ol. Early leaf removal was affected on six esters concentration only in the 2014 with different outcome. For compounds unaffected by defoliation, vintage was statistically significant source of variability, as the results of multivariate analysis have confirmed. Defoliation treatments in Cabernet Sauvignon wines from eastern continental part of Croatia should be adjusted to the weather condition in growing season.
Cilj ovoga dvogodišnjeg istraživanja bio je procijeniti učinke uklanjanja bazalnoga lista prije cvatnje na sadržaj hlapljivih spojeva Cabernet Sauvignon vina u vinogradima Ilok (istočna Hrvatska). Tijekom dviju uzastopnih godina (2013. i 2014.) primijenjena su dva različita tretmana uklanjanja bazalnih listova: uklanjanje 3 lista, 6 listova te kontrola bez uklanjanja listova. Hlapljivi spojevi dobivenih vina identificirani su i kvantificirani spregnutom tehnikom plinske kromatografije i spektrometrije masa. Tretmani rane defolijacije nisu imali učinka na koncentraciju organskih kiselina i viših alkohola, osim na octenu kiselinu i 2-metil-6-hepten-1-ol. Rana defolijacija utjecala je koncentracije šest estera samo u vinima iz 2014. godine s različitim ishodom. Za spojeve na koje rana defolijacija nije imala učinka, berba je bila statistički značajan izvor varijabilnosti, kao što su rezultati multivarijantne analize potvrdili. Tretmane rane defolijacije u Cabernet Sauvignon vinima u istočnome kontinentalnome dijelu Hrvatske potrebno je prilagoditi vremenskim prilikama tijekom vegetacijske sezone.