Florentina Ciobanu

Researches Regarding the Influence of Special Green Works on Evolution of Ripening in Four Varieties of Grapes for Wine from Vineyard Târnave

This paper was done in order to establish the influence of special green works (grapesthinning, partial deleafing and grapes bagging) on ripening evolution at the varieties: ‘MuscatOttonel’, ‘Neuburger’, ‘Traminer roz’ and ‘Sauvignon blanc’, in ecoclimatic conditions of TA¢rnaveVineyard. The grapes ripening was observed starting with 19th August, after dough ripening. Severaldeterminations were conducted regarding sugars accumulations, acidity and the weigh of 100 berries,at a one week interval (the 19th of August, 29th of August, 5th of September and 12th of September).Out of the methods known for sugars determinations within the must (refractometric method,densymetric method and chemical method) it was used the refractometric one. The principle of themethod is based on the determination of the dry matter percent within the must by using therefratometer. The content of sugars is then calculated with the aid of the corresponding tables. Theresult is expressed in g/l (sugar grams/must litres). Titration in the presence on phenolphthalein wasused to determine the total acidity within the must. The acidity is expressed in g/l H2SO4. Variant 2(deleafed) of ‘Traminer roz’ accumulated the highest sugars content. The acidity decreases with thesugars concentration. An important decrease is observed in the first period of maturation (19th ofAugust- 5th of September), excepting the ‘Neuburger’ variety, which had an acidity decrease duringthe 5th- 12th of September period.