Performance evaluation of a non-chemical weed control machine for vineyards and orchards operating with high pressure cold water
During the last several decades, environmental pollution problems caused by the extensive use of chemical herbicides have encouraged the introduction of integrated crop production. A further boost to these methods has been provided by market demand, where organic or “biologique” products are increasingly requested by consumers. In vineyards and orchards, one of the most widely used methods of non-chemical weed control is through the mechanical action of agricultural implements. Commonly, these implements are characterized by rotating blades operating inter-row, but this typology of machines could damage plant roots and it is subjected to failures in stony soils. To overcome these problems, some manufacturers have developed flame or steam weeders, but the limited operating speed leads to an increment of management costs. An innovative solution was designed by Caffini® Sprayer Equipment (Italy) with the implement called the “Grass Killer” that controls weeds with high-pressure cold water. The high-pressure water stream (around 1000 bar) is obtained with a piston pump connected to the power take off (PTO) of the tractor and it is applied on weeds through a rotating inter row disc with nozzles. The objective of this study was to evaluate the performances of this machine in terms of weed control efficiency and energy consumption. Tests were performed in an orchard connecting the “Grass Killer” to a New HollandTM T4.110LP (CNH Industrial Italia SpA Company, Turin, Italy) equipped with a controlled area network logger and a global positioning system (GPS). To measure the energy required by the piston pump of the implement, a torque-meter was installed on the PTO of the tractor. To compare the weed control efficiency of the Grass Killer, one side of the orchard rows was treated with a traditional grass mulcher operating inter row. On the day of the test, normalized difference vegetation index (NDVI) images were taken with a custom-built quadrotor flying drone before the two implements performed the weed control operation. Subsequently, 15 days later other NDVI images were shot to observe weed regrowth. The results show that the power required by the piston pump of the implement is about 27 kW, which is roughly 60% of the total power needed by the tractor to run the operation. In addition, NDVI images show that weed regrowth was much slower in the sides of the orchard rows tilled with the Grass Killer.
Massimiliano Varani won an ISHS Young Minds Award for the best poster at the VI International Symposium on Applications of Modelling as an Innovative Technology in the Horticultural Supply Chain (Model-IT 2019) in Italy in June 2019.
Massimiliano Varani, University of Bologna - DISTAL, viale G. Fanin 50, 40127 Bologna, Italy, e-mail: firstname.lastname@example.org
The article is available in Chronica Horticulturae