## 3 Results and Discussion
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline  & \multicolumn{2}{c}{**Number of Stems,**} & \multicolumn{2}{c}{**Number of Shoots,**} & \multicolumn{2}{c}{**Length of Roots,**} & \multicolumn{2}{c}{**Length of Stems, cm,**} \\ \cline{3-8} \multirow{2}{*}{**Factor**} & \(R_{adj}^{2}\) = 0.78, & \(R_{adj}^{2}\) = 0.66, & \(R_{adj}^{2}\) = 0.94, & \(R_{adj}^{2}\) = 0.71, \\  & \(F\) = 15.35, \(p\) **\textless{} 0.001** & \(F\) = 6.87, \(p\) \textless{} 0.001 & \(F\) = 45.46, \(p\) \textless{} 0.001 & \(F\) = 8.49, \(p\) \textless{} 0.001 \\ \cline{2-8} \cline{10-8}  & \(F\)-Ratio & \(p\)-Level & \(F\)-Ratio & \(p\)-Level & \(F\)-Ratio & \(p\)-Level \\ \hline Year & 254.22 & \textless{}0.001 & 79.61 & \textless{}0.001 & 479.91 & \textless{}0.001 & 48.50 & \textless{}0.001 \\ Soil & 46.69 & \textless{}0.001 & 1.29 & 0.26 & 31.05 & \textless{}0.001 & 34.82 & \textless{}0.001 \\ PGR & 4.11 & \textless{}0.001 & 14.55 & \textless{}0.001 & 102.06 & \textless{}0.001 & 13.72 & \textless{}0.001 \\ Year \(\times\) Soil & 48.86 & \textless{}0.001 & 0.03 & 0.87 & 13.48 & \textless{}0.001 & 54.22 & \textless{}0.001 \\ Year \(\times\) PGR & 3.54 & \textless{}0.001 & 2.87 & \textless{}0.001 & 29.27 & \textless{}0.001 & 2.44 & 0.02 \\ Soil \(\times\) PGR & 0.44 & 0.89 & 0.93 & 0.49 & 1.19 & 0.32 & 1.62 & 0.14 \\ Year \(\times\) Soil \(\times\) PGR & 0.37 & 0.93 & 1.57 & 0.15 & 0.83 & 0.58 & 2.19 & 0.04 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Evaluation of the effect of the research factors, PGRs, soil type, and year of vegetation, on \(M\). \(\times\)_giganteus_ bioparameters following M-GLM procedures. Figure 1: The impact of the various treatments of PGRs on stem length (**a**) depending on the soil type (**b**). Squares and circles show least-squares means. Vertical bars denote 0.95 confidence intervals. The treatment with various PGRs impacted \(M\). \(\times\)_giganteus_ biological parameters differently. For example, while Ch1, Ch2, and S2 treatments increased the number of stems (Figure 1a), R2, R3, and Ch2 treatments impacted mainly the number of shoots (Figure S2a), and R1, R2, R3, and Ch2 treatments were the most essential in case of root length (Figure S3a). The biomass is mainly formed by stems when \(M\). \(\times\)_giganteus_ is harvested [59]. Therefore, the enhancement of biomass is among the targeted goals when the crop is grown on different marginal lands, including post-military areas [60]. This goal may be achieved by applying varied agricultural practices, including treatment by PGRs [36]. The results (Table 5) showed that the dry biomass value is primarily dependent on the length of stems (Figure 1) and the variety of PGR applied (Figure 2) (\(p<0.001\)). In this regard, the gradation of factors influenced stem length and the determination of the extent to which these results depended on PGR treatment is essential for enhancing \(M\). \(\times\)_giganteus_ biomass. The results shown in Figure 1 illustrate that in the first year of vegetation in Soil I the impact of PGRs had the following order: Ch2 > Ch1 > R1 > S2; for another treatment, the effect was neglected and close to the treatment with water (control). In the second year of vegetation, the order of PGR impact was changed for Soil I: S2 > Ch2 > R2 > R3; S1 > Ch1, S3; for other treatments, the effect was neglected and close to the control. These results showed that, while for the first year of vegetation the influence of Charkor on increased root growth was the main factor related to enhancing biomass values (Figure 2), for the second year, the treatment of aboveground biomass competed with the  
Figure 2: Impact of various PGR treatments on \(M\). \(\times\)_giganteus_ dry biomass. Triangles show least square means. Vertical bars denote 0.95 confidence intervals.