# Evaluation of Autonomous Mowers Weed Control Effect in Globe Artichoke Field
## 2 Materials and Methods
### Data Collection
The measurement of the primary energy consumption of the frail mower was carried out considering the gasoline heating value, that is 12.22 kWh\(\cdot\)kg\({}^{-1}\)[43]. The frail mower work schedule considered for the estimation consisted of a total of seven treatments carried out during the arithoke growing season. Regarding the autonomous mowers, power consumptions of 0.025 kWh\(\cdot\)h\({}^{-1}\), 0.035 kWh\(\cdot\)h\({}^{-1}\) and 0.04 kWh\(\cdot\)h\({}^{-1}\) were assumed for AM1, AM2 and AM3, respectively [35; 36; 37]. For the estimation, a moving area of 150 m\({}^{2}\) and a percentage of area moved of 80% was considered. The mowing time of each autonomous mower corresponds to the value obtained by the regression model for reaching the 80% of coverage of the area (see Section 2.4 Statistical Analysis). The 150 m\({}^{2}\) area is considered to be moved two days a week per 18 weeks a year (during the arithoke growing season). Considering that each autonomous mower works for its daily maximum active time, every day of the week, the movable area per day and per week, and the energy consumption per week and per year were calculated. For each autonomous mower type, the annual energy consumption and the number of autonomous mowers needed for the management of one hectare per week were then estimated. Subsequently, the annual primary energy consumption per hectare of each autonomous mower type was calculated. In order to calculate the total primary energy consumption, the primary energy consumption of the charging bases with boundary wires was also calculated for each autonomous mower type. The power consumption of the charging bases with boundary wires was measured with a Primera-Line Wattage and current meter PM 231 E (Brennenstuhl\({}^{\lx@sectionsign}\), Baar, Switzerland) and corresponded to 0.0059 kWh for AM3 and AM2, and to 0.0025 kWh for AM1. All the autonomous mowers tested were set in ECOmode, which means that the boundary wires consumed energy only during moving. In accordance with the methodology followed by [PERSON] et al. [44] for the estimation of the primary energy consumption of the autonomous mowers and the charging bases with the boundary wires, the efficiency of the Italian National Electric System equal to 0.562 [45], and the charging efficiency of Li-ion batteries that is 91% [46] were considered. The costs of the selected autonomous mower and the fail mower weed management systems were estimated in relation to the management of 1 ha. For the two weed management systems the above-mentioned work-schedules described for the estimation of primary energy consumption were considered. Fixed costs (purchase cost and depreciation) and variable costs (gasoline consumption and labor for the fail mower, electric energy consumption for the autonomous mower and maintenance for both the machines) were estimated. Labor cost was EUR 25 h\({}^{-1}\), gasoline and electric energy costs were EUR 1.38 L\({}^{-1}\) and EUR 0.20 kWh\({}^{-1}\), respectively. A machine life of 1500 h and 15,000 h were assumed for the fail mower and the autonomous mower respectively. It was considered that at end of their life both machines would not have a commercial value. For the autonomous mower weed management the cost of the installation of boundary wire (EUR 1.5 m\({}^{-1}\)) and the related depreciation were also considered. A boundary wire life of 10 years was assumed.