EFFECT OF GENOTYPE ON GRAPE QUALITY PARAMETERS IN COOL CLIMATE CONDITIONS

Abstract

Traditional vine-producing regions grow Vitis vinifera L. cultivars, which are sensitive to downy mildew (Plasmopara viticola). Large amounts of pesticide residues found in imported grapes has raised the question if it would be possible in the Nordic countries ? as non-traditional vine growing countries ? to grow grapes without chemicals, and thereby to get a healthier yield. Nowadays most common cultivars grown in Estonia are obtained by crossing V. vinifera, V. amurensis and V. labrusca. The aim of the present experiment was to find out the effect of genotype on grape quality in cool climate conditions. The research was conducted with red (?Hasanski Sladki?, ?Rondo?, ?Zilga?, ?Kuzminski Sinii?) and white (?Jubilei Novgoroda?, ?Korinka Russkaja?, ?Severnoi Rannii?, ?Supaga?) grape cultivars. The plantation was established with double trunk training at the experimental vineyard (northern latitude 57-59°) of the Estonian University of Life Sciences. The experiment was carried out with red grapes in 2011 and 2012, and with white grapes in 2012. The results of the study indicated, that fruits of all cultivars achieved the minimum content of soluble solids required for table grapes by mid-September. The highest soluble solids content among red grape cultivars was found in ?Hasanski Sladki? (18.9°Brix) and among white cultivars in ?Jubilei Novgoroda? (16.5°Brix) and in Severnoi Rannii (17°Brix). The sweetest red grape was ?Kuzminski Sinii? (Brix/acids ratio 19) and the white grape was ?Severnoi Rannii? (22). Among red grapes ?Kuzminski Sinii? and among white ones ?Supaga? had the highest total phenolic content (540 and 168 mg 100 g-1, respectively).