3. Modificational Variability of the Technological Indicators of the Super Ran Bolgar Table Grape Variety under the Influence of the Rootstock

The study monitored the modificational variability of the technological indicators of the Super Ran Bolgar table grape variety, under the influence of four rootstocks – Rupestris du Lot (Montikola), Berlandieri x Riparia S04, Shasla x Berlandieri 41b and Ferkal. The experiment was set in 1988 in the test vineyard of IASS “Obraztsov Chiflik” – Rousse. The comparative experiment was that with Rupestris du Lot and the data covered a 7-year period (1999-2005). The technological parameters were determined in accordance with the accepted methods: the mechanical composition of the grapes – by the classical method of Prostoserdov; the sugar content was determined with the Dujardin must meter, and total acids – by titration with 0.1 n NaOH. The transportability was determined theoretically and experimentally by measuring the resistance of the ripe berry to pressure and separation from the pedicel. In order to ascertain the established differences in the particular indicators, the analysis of variance model was applied, using Student’s t criterion. Changes in some technological parameters were found, some of which significant (statistically proven) – mechanical composition and resistance of the berry to separation from the pedicel and others, not statistically proven, showed certain trends – chemical composition and hardiness of the berry to pressure.