Performance evaluation of a non-chemical weed control machine for vineyards and orchards operating with high pressure cold water

In the last decades, environmental pollution problems due to the extensive use of chemical herbicides caused the introduction of alternative methods to protect the crop. Moreover, a further boost to the introduction of these new methods has been given by the market, where organic products are increasingly requested by the consumers. Regarding vineyards and orchards, one of the most widely used methods of non-chemical weed control is through the mechanical action of appropriate agricultural implements. Commonly these implements are characterized by rotating blades operating inter-row, but this typology of machines could damage plant roots and are subjected to failures in stony soils. To overcome these problems some manufacturers developed flame or steam weeder, but the limited operating speed leads to an increment of management costs. An innovative solution was designed by Caffini S.p.a (Italy) with the implement “Grass Killer” that perform the weed control with high-pressure cold water. The high-pressure water stream (around 1000 bar) is obtained with a piston pump connected to the PTO of the tractor and it is applied on the weed through a rotating inter row disc with nozzles. The objective of this study was to evaluate the performances in terms of weed control efficiency and energy consumption of this implement. Tests have been performed in an orchard connecting the “Grass Killer” to a New Holland T4.110LP equipped with a CAN Logger and a GPS. Moreover, in order to measure the energy required by the piston pump of the implement, a torque-meter was installed on the PTO of the tractor. Furthermore, the weed control efficiency was monitored with a flying drone equipped with an NDVI camera. The results show that the implement removes the majority of the weed with only one treatment. In addition, the power required by the piston pump of the implement is about 27 kW, that is roughly the 60% of the total power needed by the tractor to run the operation.