## 3 Results and Discussions
### Anatomical Analysis of Leaves by Light Microscopy
In column and for each period, different letters indicate significant differences (\(p<\) 0.05). about 70%, while the spongy mesophyll is about 25% of the entire mesophyll/leaf blade. The upper epidermis is generally made up of large cells with a longitudinal diameter of 32.68 \(\pm\) 1.41 um and a transverse diameter of 15.48 \(\pm\) 0.99 um; these cells then appear elongated longitudinally. The thickness of the cuticle in the upper epidermis is 2.47 \(\pm\) 0.61 um (Figure 1A). The cells of the lower epidermis are smaller than those of the upper epidermis: their average longitudinal diameter is 11.28 \(\pm\) 0.98 um, while the transverse one is 12.03 \(\pm\) 1.02 um. These cells then appear isodiametric (Figure 1A). The thickness of the lower epidermis cuticle is 2.43 \(\pm\) 0.61 um. To better understand the effect of foliar treatments in leaf anatomical parameters, data are summarized in Table 4. The two sampling times (t1 and t2) did not show any differences from a structural point of view, and for this reason the data averages of the two times are shown in Table 4.  
The results show significant differences for some leaf anatomical features. The leaves of the Treat 2 showed a significant increase in cuticle, of both the upper and lower epidermis (Figure 1B; Table 4). In tomato, some authors [36] indicate that the concentration of foliar N affects the thickness of the epidermal cuticle. It appears quite established that high concentrations of N lead to a decrease in the cuticle thickness; pe \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & **Untreat** & **Treat 1** & **Treat 2** & **Treat 3** & **Treat 4** \\ \hline Upper epidermis cuticle & 2.47 \(\pm\) 0.61 c & 2.26 \(\pm\) 0.97 c & 7.46 \(\pm\) 1.08 a & 3.90 \(\pm\) 0.59 b & 4.71 \(\pm\) 0.90 b \\ \hline Longitudinal diameter of upper epidermis cells (μm) & 32.68 \(\pm\) 1.41 a & 32.75 \(\pm\) 1.61 a & 21.16 \(\pm\) 0.81 c & 26.82 \(\pm\) 1.77 b & 27.22 \(\pm\) 0.62 b \\ \hline Transversal diameter of upper epidermis cells (μm) & 15.48 \(\pm\) 0.99 a & 15.61 \(\pm\) 0.70 a & 17.61 \(\pm\) 0.78 a & 16.81 \(\pm\) 0.48 a & 14.05 \(\pm\) 0.41 b \\ \hline \% Palisade tissue & 76.44 \(\pm\) 2.02 a & 77.15 \(\pm\) 3.45 a & 59.36 \(\pm\) 2.14 c & 67.82 \(\pm\) 2.58 b & 72.42 \(\pm\) 4.54 ab \\ \hline \% Spongy tissue & 23.55 \(\pm\) 1.87 c & 22.85 \(\pm\) 2.01 c & 40.63 \(\pm\) 1.98 a & 32.18 \(\pm\) 3.24 b & 27.58 \(\pm\) 3.57 bc \\ \hline Longitudinal diameter of lower epidermis cells (μm) & 11.28 \(\pm\) 0.98 b & 15.32 \(\pm\) 2.62 a & 15.85 \(\pm\) 1.81 a & 12.30 \(\pm\) 1.12 b & 14.40 \(\pm\) 1.21 ab \\ \hline Transversal diameter of lower epidermis cells (μm) & 12.03 \(\pm\) 1.02 a & 12.28 \(\pm\) 1.01 a & 11.82 \(\pm\) 0.88 a & 10.27 \(\pm\) 1.06 a & 10.22 \(\pm\) 1.11 a \\ \hline Lower epidermal cuticle thickness (μm) & 2.43 \(\pm\) 0.61 b & 2.39 \(\pm\) 0.48 b & 6.81 \(\pm\) 0.89 a & 2.05 \(\pm\) 0.41 b & 2.31 \(\pm\) 0.91 b \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Anatomical characteristics of hop leaves for each fertilizer plan. In rows, different letters indicate statistical differences at \(p<\) 005 with [PERSON]’s test. Figure 1: Transversal section of hop leaf cv. Cascade stained with PAS-Amido Black. (**A**) Untreat; (**B**) Treat 2. Legends: ue = upper epidermis; pt = palisade tissue; sp = spongy tissue; le = lower epidermis; c = cuticle thickness. different concentrations of N have produced fruits with different cuticle thickness [5], and thinner if N concentration was high. In our study organic nitrogen has positive effects on increasing the cuticle thickness. Furthermore, the percentage of palisade tissue was also found to be significantly lower in Treat 2. Treat 2 is characterized by a low input of K in exchange for a high input of organic N (Table 1). [PERSON] et al.