## 3 Results and Discussion
Adjuvant concentration was the only factor significantly (\(p<0.05\)) influencing the features of D\({}_{v0.9}\), SMD, and RS. The other two factors (water source, adjuvant type) did not significantly affect the examined features (\(p>0.05\)). Table 6 presents the results of post-hoc multiple comparison tests for the concentration factor and traits D\({}_{v0.9}\), SMD, and RS. For feature D\({}_{v0.9}\), no statistically significant differences were found between the 50 and 100% concentrations (Table 6, \(p>0.05\)). In contrast, the D\({}_{v0.9}\) values obtained for the 50 and 100% concentrations differed significantly in relation to the control (0%). In the case of the SMD feature, a statistically significant difference was found between the control group (0%) and the concentration at the level of 100%. Similar results were seen in [9; 22] (Table 6, \(p<0.05\)). For the RS feature, no statistically significant differences were found between the 50 and 100% concentrations (Table 6, \(p>0.05\)). However, the RS value obtained for the 50 and 100% concentrations differed significantly from that of the control group (0%). Data presented in Table 7 indicate a decrease in the percentage of droplet size fraction of 0-100 \(\upmu\)m when the OL adjuvant was added to the spray solution with the WS water type. The reduction was from 18.9% for the \"control\" (water only) treatment, to 11.9 and 15.7% upon using 50% and 100% concentrations, respectively. These results are in agreement with the findings of [10; 20]. The opposite trend was observed when adding HY adjuvant. This effect would be lower if we accumulate the 0-100 \(\upmu\)m fraction with the 100-150 \(\upmu\)m fraction, since both fractions are responsible for spray drift. In the table, it is noticeable that adding the OL adjuvant at100% concentration resulted in a higher percentage of the 0-150 \(\upmu\)m fraction (accumulated) than in using the 50% concentration. For the WUP water type, the addition of both types of adjuvants with both concentrations resulted in a decrease in the percentage of the 0-100 \(\upmu\)m fraction of droplet size. However, the OL adjuvant showed a greater decrease in this fraction. Nearly the same trend was observed when accumulating the 0-100 \(\upmu\)m and 100-150 \(\upmu\)m fractions of droplet size. The coarse droplet size (\(\geq\)500 \(\upmu\)m) fractions, which can be responsible for the losses of the spray solution to the ground, increased after adding both types of adjuvants to the two concentrations, and \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Trait** & **Concentration** & **0\%** & **50\%** & **100\%** \\ \hline \multirow{3}{*}{D\({}_{v0.9}\)} & 0\% & & 0.0016 \({}^{*}\) & 0.0000 \({}^{*}\) \\ \cline{2-5}  & 50\% & 0.0016 & & 0.4550 \\ \cline{2-5}  & 100\% & 0.0000 & 0.4550 & \\ \hline \multirow{3}{*}{SMD} & 0\% & & 0.1317 & 0.0124 \({}^{*}\) \\ \cline{2-5}  & 50\% & 0.1317 & & 1.0000 \\ \cline{2-5}  & 100\% & 0.0124 \({}^{*}\) & 1.0000 & \\ \hline \multirow{3}{*}{RS} & 0\% & & 0.0053 \({}^{*}\) & 0.0005 \({}^{*}\) \\ \cline{2-5}  & 50\% & 0.0053 \({}^{*}\) & & 0.9989 \\ \cline{1-1} \cline{2-5}  & 100\% & 0.0005 \({}^{*}\) & 0.9989 & \\ \hline \hline \end{tabular} \({}^{*}\) Significant at \(p<0.05\).  
\end{table} 
Table 6: Results of the post-hoc multiple comparison test for the concentration factor. for both water types. In the case of fractions 150-200 \(\upmu\)m and 200-250 \(\upmu\)m, application of both adjuvants increased the number of droplets in the proportion of spray, independent of the adjuvant type and water source. This would have a positive effect on the number of droplets being in contact with the plant leaf surface during spraying, hence increasing the efficiency of spraying. Table 8 presents the results of non-parametric tests (probability \(p\)-value) verifying the significant influence of the water source, type of adjuvant, and its concentration on the droplet size fractions.