Differences in grape quality between cv. ‘Rebula’ (Vitis vinifera L. cv. 'Rebula') and ‘Chardonnay’ (Vitis vinifera L. cv. 'Chardonnay') in Goriška Brda winegrowing district

Abstract

Regarding yield cultivars ‘Rebula’ and ‘Chardonnay’ represent important white vine cultivars in Goriška brda. Grape quality of both cultivars is quite variable between years and locations Brda region. The most important reasons are: agitation of the relief, weather conditions and impropriate traditional growing manner. In the year 2002 the grape quality and sugar content in the grapes respectively was better than in year 2000 and especially better than year 2001 in which the sugar content was the worst. The weather conditions in this three years showed no noticeable differences, however they shouldn’t be disregarded. Planting and growing of both cultivars is dissuaded in N, NW and NE of Brda region. The highest average sugar content in grapes of cultivar ‘Rebula’ was determinated in location of Vedrijan, Vipolže, Vrhovlje and Neblo. ‘Chardonnay’ grapes showed the highest contents of sugars in location of Kozana, Cerovo, Vrhovlje and Mirnik. Because of the variability in sugar content of grapes between locations as well as in the individual location, the revision and exclusion of impropriate viticultural positions for individual vine cultivar is recommended.