## 3 Results and Discussion
### Summary of 5-Year Observation
The 2020 Regent vines produced the smallest fruit over the entire study cycle, significantly. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**Combination (A)** & 101-14 Mgt & 18.6 \(\pm\)1.7 & 101.8 \(\pm\)25.3 & 84.2 \(\pm\)17.5 & 1.20 \(\pm\) 0.1 & 19.5 \(\pm\) 1.2 & 1.9 \(\pm\) 0.6 & 9.6 \(\pm\) 3.0 \\  & SORI & 18.5 \(\pm\) 2.1 & 108.9 \(\pm\) 36.2 & 87.7 \(\pm\) 23.2 & 1.2 \(\pm\) 0.2 & 20.5 \(\pm\) 1.6 & 2.1 \(\pm\) 0.8 & 10.4 \(\pm\) 4.1 \\  & 161-49 C & 17.8 \(\pm\) 2.8 & 99.0 \(\pm\) 17.5 & 75.7 \(\pm\) 11.3 & 1.3 \(\pm\) 0.1 & 20.6 \(\pm\) 1.7 & 1.8 \(\pm\) 0.5 & 8.9 \(\pm\) 2.5 \\  & 5 BB & 18.7 \(\pm\) 2.8 & 97.2 \(\pm\) 28.9 & 76.9 \(\pm\) 17.2 & 1.3 \(\pm\) 0.1 & 20.7 \(\pm\) 1.6 & 1.9 \(\pm\) 0.7 & 9.3 \(\pm\) 3.8 \\  & SO4 & 20.1 \(\pm\) 2.5 & 113.7 \(\pm\) 29.8 & 88.3 \(\pm\) 19.6 & 1.3 \(\pm\) 0.1 & 21.6 \(\pm\) 2.2 & 2.4 \(\pm\) 0.8 & 11.8 \(\pm\) 4.2 \\  & 125 AA & 20.9 \(\pm\) 2.5 & 133.8 \(\pm\) 36.1 & 85.8 \(\pm\) 22.6 & 1.6 \(\pm\) 0.1 & 20.8 \(\pm\) 1.6 & 2.9 \(\pm\) 0.9 & 14.4 \(\pm\) 4.8 \\  & Own root & 20.5 \(\pm\) 2.4 & 114.8 \(\pm\) 35.2 & 87.7 \(\pm\) 21.1 & 1.3 \(\pm\) 0.1 & 21.2 \(\pm\) 1.5 & 2.4 \(\pm\) 0.9 & 12.1 \(\pm\) 4.6 \\ \cline{2-10}  & _p-value_* & _<0.0001_ & _<0.0001_ & _<0.0001_ & _<0.0001_ & _<0.0001_ & _<0.0001_ & _<0.0001_ \\ \hline
**Year (B)** & 2016 & 19.7 \(\pm\) 2.3 & 123.8 \(\pm\) 21.3 & 91.2 \(\pm\) 7.7 & 1.4 \(\pm\) 0.2 & 21.1 \(\pm\) 0.6 & 2.5 \(\pm\) 0.6 & 12.3 \(\pm\) 3.2 \\  & 2017 & 18.2 \(\pm\) 2.2 & 103.4 \(\pm\) 18.4 & 81.3 \(\pm\) 5.5 & 1.3 \(\pm\) 0.2 & 19.6 \(\pm\) 0.7 & 1.9 \(\pm\) 0.5 & 9.6 \(\pm\) 2.7 \\  & 2018 & 21.5 \(\pm\) 1.1 & 148.5 \(\pm\) 18.4 & 109.3 \(\pm\) 10.3 & 1.4 \(\pm\) 0.1 & 22.9 \(\pm\) 1.3 & 3.2 \(\pm\) 0.5 & 16.1 \(\pm\) 2.5 \\  & 2019 & 21.2 \(\pm\) 0.9 & 109.9 \(\pm\) 13.4 & 83.9 \(\pm\) 7.7 & 1.3 \(\pm\) 0.1 & 21.3 \(\pm\) 0.1 & 2.3 \(\pm\) 0.3 & 11.6 \(\pm\) 1.6 \\  & 2020 & 15.8 \(\pm\) 0.4 & 63.9 \(\pm\) 6.7 & 53.1 \(\pm\) 2.6 & 1.2 \(\pm\) 0.1 & 18.5 \(\pm\) 0.4 & 1.0 \(\pm\) 0.1 & 5.0 \(\pm\) 0.6 \\ \cline{2-10}  & _p-value_* & _<0.0001_ & _<0.0001_ & _<0.0001_ & _<0.0001_ & _<0.0001_ & _<0.0001_ & _<0.0001_ \\ \hline
**A \(\times\) B** & _p-value_* & _<0.0001_ & _<0.0001_ & _<0.0001_ & _<0.0001_ & _<0.0001_ & _<0.0001_ & _<0.0001_ \\ \hline \hline \end{The grape extract level of the studied grape variety was significantly modified by the type of rootstock used. Grapes from bushes grafted on SO4 rootstock were characterized by the highest extract level, while from 101-14 Mgt rootstock by the lowest. There was no significant effect of rootstock on the level of the examined parameter in the case of types: SORI, 161-49 C, 5 BB, and 125 AA. The years of the study significantly modified the level of the evaluated parameter. The fruit had the highest extract in 2018 and the lowest in 2020, significantly. Ref. [19] demonstrated a significant impact of the year of research on the level of grapevine extract of the Albarino variety grafted on nine types of rootstocks. Ref. [51], evaluating the effect of rootstocks on the extract content of Chardonel grapevines, found that own-root vines were characterized by significantly higher extract levels than those grafted on Cyntiana and 5 BB rootstocks. Grapevine fruit yield of Regent cultivar ranged from 1.78 to 2.87 kg\(\cdot\)bush\({}^{-1}\), i.e., from 8.90 to 14.35 t\(\cdot\)ha\({}^{-1}\), and it differed significantly among the evaluated combinations (Table 2). It was shown that on average for the whole cycle of studies, shrubs grafted on 125 AA rootstock yielded the best among all evaluated plants, significantly, while the 101-14 Mgt, 161-49, and 5 BB grafts yielded the lowest, significantly. There were no significant differences in yield between shrubs grafted on SO4 and own-rooted ones. A significant effect of the year of study on the evaluated parameter was found. In 2018, the bushes of the studied grapevine cultivar yielded the best, significantly, while in 2020 the lowest, significantly.