STUDY ON THE INFLUENCE OF RUPESTRIS DU LOT ROOTSTOCK ON SOME TECHNOLOGICAL TRAITS OF MUSCAT RUSENSKI AND SUPER RAN BOLGAR TABLE GRAPE CULTIVARS

The choice of rootstock is important not only for the power that it induces on the grafted variety of grapes, but also with respect to its effects on mineral nutrition, content of sugars, total acids and other technological traits. Two table vine varieties-Misket Rusenski and Super ran Bolgar were the objective of the study, grafted on two different SO4 rootstocks (which is widely used in practice and thus accepted control) and Rupestris du Lot (with common name Montikola). A total of 12 technological traits were reported for both varieties during the vegetation. Data obtained were statistically analyzed using Fisher (F) and Student (t) evaluation criteria. The results showed different levels of significance of the individual traits in both varieties using Rupestris du Lot rootstock compared to the control. Via Fisher's criterion it was found that 58 % of the traits showed significant differences in Montikola rootstock compared to the control, as the comparison was made based on variability of the traits, while when using the Student criterion for statistical evaluation, the percentage was only 33. The highest significance was reported in the influence of the rootstock on the traits: number of seeds in 100 berries and resistance of berry to pick up from the fruit stalk for cv. Misket Rusenski, determined via both criteria. Comparing the samples tested regarding variability, significant differences were reported of Rupestris du Lot rootstock for the traits: % of berries in grapes and % of mesocarp in berry mass for the same variety. Rupestris du Lot rootstock has significant influence on content of sugars, total acids and mass of 100 seeds in cv. Super ran Bolgar (by the criterion of Fisher) and traits: % of mesocarp of berry mass and % of skin of berry mass (found by the criterion of Student). These traits influence significantly on tasting qualities of grapes and technological qualities of wine. As a result of the analysis of both vines (Misket Rusenski and Super ran Bolgar) a high degree of variability of the values of some technological traits was determined, and it is recommended both criteria to be used for better statistical evaluation. Keyword: Rupestris du Lot rootstock, statistical evaluation, table vine varieties Misket Rusenski and Super ran Bolgar (Vitis vinifera L.), technological traits