# Evaluation of Autonomous Mowers Weed Control Effect in Globe Artichoke Field
## 4 Discussion  
The aim of this study was to evaluate the applicability of autonomous mowers with random trajectories for weed management in the globe artichoke crop. During the research, two trials were performed. In the first trial the performances of three different autonomous \begin{table}
\begin{tabular}{c c c c c c} \hline  & \begin{tabular}{c} **Average** \\ **Weeds** \\ **Height** \\ \end{tabular} & \begin{tabular}{c} **Weed Cover** \\ **Percentage** \\ \end{tabular} & \begin{tabular}{c} **Above-** \\ **Ground Weed** \\ **Biomass** \\ \end{tabular} & \
\begin{tabular}{c} **Number of** \\ **Artichoke Heads** \\ **per Hectare** \\ \end{tabular} &
\begin{tabular}{c} **Weight of** \\ **Artichoke Heads** \\ **per Hectare** \\ \end{tabular} \\ \hline Weed management systems & (cm) & (\%) & (g d.m. m\({}^{-2}\)) & n\(\cdot\)ha\({}^{-1}\) & Mg-ha\({}^{-1}\) \\ \hline Autonomous mower weed management system & 3.40 & 9.41 & 71.76 & 32,098.77 & 6.58 \\ \hline Conventional weed management system & 13.63 & 18.67 & 143.67 & 35,185.19 & 6.12 \\ \hline \end{tabular}
\end{table} 
Table 7: Mean values of average weeds height, weed cover percentage, above-ground weed biomass, number and weight of artichoke heads per hectare for both the weed management systems. \begin{table}
\begin{tabular}{l c c} \hline  & & **Fail Mower** \\ \hline \hline \multirow{4}{*}{\
\begin{tabular}{l} Purchase cost \\ Depreciation of purchase cost \\ Maintenance cost \\ Depreciation of maintenance cost \\ Labor cost \\ Gasoline cost \\ Total annual cost \\ \end{tabular} } &
\begin{tabular}{c} Unit \\ EUR\(\&\) & 3280.00 \\ EUR\(\cdot\)ha\({}^{-1}\cdot\)year\({}^{-1}\) & 269.92 \\ EUR\(\cdot\) & 1640.00 \\ EUR\(\cdot\)ha\({}^{-1}\cdot\)year\({}^{-1}\) & 134.96 \\ EUR\(\cdot\)ha\({}^{-1}\cdot\)year\({}^{-1}\) & 3086.00 \\ EUR\(\cdot\)ha\({}^{-1}\cdot\)year\({}^{-1}\) & 170.91 \\ EUR\(\cdot\)ha\({}^{-1}\cdot\)year\({}^{-1}\) & 3661.80 \\ \hline \multicolumn{4}{c}{**Autonomous Mower (AM2)**} \\ \hline \hline Purchase cost 1  & EUR & 5190.00 \\ Depreciation of purchase cost 1  & EUR\(\cdot\)year\({}^{-1}\) & 856.23 \\ Maintenance cost 1  & EUR & 1557.00 \\ Depreciation of maintenance cost 1  & EUR\(\cdot\)year\({}^{-1}\) & 256.87 \\ EUR\(\cdot\)year\({}^{-1}\) & 17.13 \\ Cost of an autonomous mower & EUR\(\cdot\)year\({}^{-1}\) & 1130.22 \\ Cost of all the autonomous mowers & EUR\(\cdot\)ha\({}^{-1}\cdot\)year\({}^{-1}\) & 2486.49 \\ EUR\(\cdot\)ha\({}^{-1}\cdot\)year\({}^{-1}\) & 1089.99 \\ EUR\(\cdot\)ha\({}^{-1}\cdot\)year\({}^{-1}\) & 109.00 \\ EUR\(\cdot\)ha\({}^{-1}\cdot\)year\({}^{-1}\) & 6.35 \\ EUR\(\cdot\)ha\({}^{-1}\cdot\)year\({}^{-1}\) & 2601.84 \\ \hline \end{tabular}
\end{table} 
Table 8: Cost estimation of the two weed management systems. mowers were evaluated, with the aim of identifying the most suitable one for weed control in the crop. In the second trial, the autonomous mower weed management system was compared with a conventional weed management system based on the use of a walk-behind flail mower. Concerning the first trial, results showed that all three autonomous mowers were able to manage the experimental area. Despite differing in their main characteristics, all the autonomous mowers achieved coverage values around the target percentage of 80% after 180 min of moving. Significant differences were revealed only between AM2 and AM1. AM2 covered a slightly higher percentage of area after 120 (72.42% vs. 64.19%) and 180 min of moving (83.83% vs. 78.75%). This was probably due to the higher forward speed of AM2 compared to AM1 (0.65 vs. 0.38 m\(\cdot\)s\({}^{-1}\)). No statistically significant differences emerged between AM2 and AM3, nor between AM3 and AM1. This latter result suggested that the smaller size of AM1 probably compensated for the slower forward speed compared to AM3 (0.38 vs. 0.61 m\(\cdot\)s\({}^{-1}\)). Moreover, [PERSON] et al. [26] found that smaller dimensions of an autonomous mower could facilitate the movement of the machine between obstacles, represented in this case by artichoke plants.