## 3 Results and Discussion
### Effect of Growing Medium on the Growth and Yield
\begin{table}
\begin{tabular}{c c c c c c c c c c c c c c c c c} \hline \hline \multicolumn{1}{c}{\(\mathbf{C\times GM}\)} & \multicolumn{2}{c}{**Leaves**} & \multicolumn{3}{c}{**Plant Height**} & \multicolumn{3}{c}{**Root**} & \multicolumn{3}{c}{**Stem**} & \multicolumn{3}{c}{**Leaves**} \\  & & \multicolumn{2}{c}{**n\({}^{\circ}\)**} & & \multicolumn{3}{c}{**(cm)**} & & \multicolumn{3}{c}{**(mg d.w.)**} & & \multicolumn{3}{c}{**(mg d.w.)**} & & \multicolumn{3}{c}{**(mg d.w.)**} \\ \hline IMP \(\times\) TC & 3.0 \(\pm\) & 0.5 & 7.0 \(\pm\) & 0.7 & cde & 5.4 \(\pm\) & 1.9 & 6.7 \(\pm\) & 1.2 & cde & 20.0 \(\pm\) & 0.1 & abc \\ IMP \(\times\) C1-60 & 2.9 \(\pm\) & 0.5 & 6.6 \(\pm\) & 0.9 & de & 5.2 \(\pm\) & 2.2 & 4.8 \(\pm\) & 0.4 & de & 14.4 \(\pm\) & 2.4 & c \\ IMP \(\times\) C1-30 & 2.9 \(\pm\) & 0.3 & 6.5 \(\pm\) & 0.8 & e & 6.0 \(\pm\) & 2.1 & 5.9 \(\pm\) & 0.8 & cde & 15.8 \(\pm\) & 2.4 & bc \\ IMP \(\times\) C2-60 & 3.0 \(\pm\) & 0.3 & 7.5 \(\pm\) & 0.7 & bc & 5.0 \(\pm\) & 2.5 & 4.9 \(\pm\) & 0.4 & de & 17.5 \(\pm\) & 0.2 & abc \\ IMP \(\times\) C2-30 & 3.0 \(\pm\) & 0.3 & 7.1 \(\pm\) & 0.7 & cde & 5.3 \(\pm\) & 0.7 & 4.7 \(\pm\) & 0.5 & de & 16.3 \(\pm\) & 3.4 & abc \\ IMP \(\times\) C3-60 & 3.0 \(\pm\) & 0.4 & 6.8 \(\pm\) & 0.5 & cde & 7.5 \(\pm\) & 2.4 & 4.1 \(\pm\) & 0.6 & e & 13.8 \(\pm\) & 1.8 & c \\ IMP \(\times\) C3-30 & 3.0 \(\pm\) & 0.3 & 6.8 \(\pm\) & 0.9 & cde & 5.4 \(\pm\) & 2.0 & 6.0 \(\pm\) & 1.0 & cde & 14.3 \(\pm\) & 2.0 & c \\ VDI \(\times\) TC & 1.9 \(\pm\) & 0.3 & 8.3 \(\pm\) & 0.9 & a & 5.1 \(\pm\) & 0.5 & 8.1 \(\pm\) & 0.2 & bcd & 14.6 \(\pm\) & 1.3 & c \\ VDI \(\times\) C1-60 & 2.0 \(\pm\) & 0 & 7.2 \(\pm\) & 0.8 & cd & 6.7 \(\pm\) & 0.3 & 8.7 \(\pm\) & 2.5 & bc & 16.1 \(\pm\) & 3.6 & abc \\ VDI \(\times\) C1-30 & 2.0 \(\pm\) & 0 & 8.2 \(\pm\) & 0.7 & a & 7.4 & \(\pm\) & 0.1 & 12.1 \(\pm\) & 3.3 & a & 22.7 \(\pm\) & 3.1 & a \\ VDI \(\times\) C2-60 & 2.0 \(\pm\) & 0 & 8.4 \(\pm\) & 0.7 & a & 5.8 \(\pm\) & 0.9 & 12.3 \(\pm\) & 0.5 & a & 20.2 \(\pm\) & 3.3 & abc \\ VDI \(\times\) C2-30 & 1.8 \(\pm\) & 0.4 & 8.0 \(\pm\) & 1.3 & ab & 6.5 \(\pm\) & 1.8 & 9.5 \(\pm\) & 0.8 & abc & 18.6 \(\pm\) & 1.5 & abc \\ VDI \(\times\) C3-60 & 2.0 \(\pm\) & 0 & 7.9 \(\pm\) & 0.6 & ab & 6.6 \(\pm\) & 1.4 & 12.0 \(\pm\) & 0.1 & a & 19.6 \(\pm\) & 1.2 & abc \\ VDI \(\times\) C3-30 & 2.0 \(\pm\) & 0.3 & 8.0 \(\pm\) & \(\pm\) & 0.7 & ab & 8.8 \(\pm\) & 1.4 & 11.6 \(\pm\) & 0.3 & ab & 22.3 \(\pm\) & 1.1 & ab \\ Significance & & \multicolumn{3}{c}{**} \\ \hline \multicolumn{1}{c}{} & \multicolumn{3}{c}{**} & \multicolumn{3}{c}{The values are means \(\pm\) standard deviation. Within each column, different letters indicate significant differences according to [PERSON]’s test at \(p\leq\) 0.05. IMP: Imperial lettuce cv; VDI: Verde d’Inverno lettuce cv; TC: Peat-based substrate; C1-60: 60\% Composed 1 + 40% Peat; C1-30: 30\% Composed 1 + 70% Peat; C2-60: 60\% Composed 2 + 40% Peat; C2-30: 30\% Composed 2 + 70% Peat; C3-30: 30\% Composed 3 + 70% Peat; C3-60: 60\% Composed 3 + 40% Peat; ns: not significant; significance **: \(p<\) 0.01; ***: \(p<\) 0.001. & \multicolumn{3}{c}{**} \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Effect of the _cultivar_ (C) and _growing medium_ (_GM_) interaction on the number of leaves; plant height; and root, stem, and leaves dry weight per plant at 33 days after sowing. In Table 7, the effect of the cultivar (C) and growing medium (GM) interaction on the number of leaves; plant height; dry weight of root, stem, and leaves; and yield 54 days after sowing is reported. IMP lettuce grown on all based-compost growing media, except C1-30, gave a greater leaf number than IMP \(\times\) TC; meanwhile, for VDI, growing media did not influence leaf number. C1-60 and C2-60 growing media positively affected the height of IMP lettuce plants, while the other substrates were comparable to the control (IMP \(\times\) TC). VDI \(\times\) C3-60 and VDI \(\times\) C3-30 were shorter than VDI lettuce \(\times\) TC.