Special green works influence on yield quantity and quality at grape varieties for flavoured and semi-flavored wines from S.C.D.V.V. Blaj.

Abstract

This paper was done in order to establish the influence of special green works (grapesthinning, partial deleafing and grapes bagging) on yield quantity and quality at the varieties: MuscatOttonel, Neuburger, Traminer roz and Sauvignon blanc, in the ecoclimatic conditions of TA¢rnaveVineyard. Harvesting took place at end of September. To assess the quantity of harvest was set theaverage number of grapes per vine, average weight of a grape and the vine production. Knowing thenumber of vines per hectare the yield per hectare was calculated, expressed in t/ha. For thesedeterminations were made direct measurements in the field. Quality of wine varieties can be expressedby mechanical analysis of the grape, determining composition, structure and grain indices. The qualityof grapes from the vine represents a very important feature of varieties. This refers to the accumulationof reducing sugars and acidity in the grapes. Carbohydrate concentration, performed at full maturity, isa characteristic of grapes variety, vineyard and harvest year. Analyzing production in terms of variety,there is a superior significant difference at Sauvignon blanc compared to the other three varieties,followed by Muscat Ottonel and Traminer roz. Analyzing the interaction of the two factors (variety,special green works), the highest yields were obtained from Sauvignon blanc V3, followed atinsignificant difference by Sauvignon Blanc variants Mt and V2. For all varieties is noted that inrelation to the applied green work, the smallest productions were obtained at V1, this being due to thesmaller number of grapes per vine. The greatest influence on yield differences were exerted by varietyand variety-green work interaction, while the green work has the smallest influence. Thus, SauvignonBlanc stands out with the highest yields, regardless of the green work used. The amount of sugar atMuscat Ottonel does not differ significantly from any other variety, being very close to the othervarieties. Following the accumulation of sugar under the influence of green works, differs significantlysuperior variant V2, which confirms that the partial defoliation favorises the sugar accumulation.Under the combined action of the two factors, stand out also variant V2 of Traminer roz. Consideringthe total acidity of the must, after execution of the green works, there is a decrease of acidity to specialgreen work variants. Cumulative influence variety-green work leads to the highest values of allvariants, Neuburger, followed by Sauvignon Blanc and Muscat Ottonel.