Tensorfield Agriculture, based in the California Bay Area, USA, is currently testing its Tensorbot V2 robotic chassis. Initial studies with large growers in the Salinas Valley, California indicate 40% cost reductions compared with in hand weeding.
Developed for operation in row crops in the ‘post herbicide world’ the Tensorbot precision spray robot targets micro-doses of superheated vegetable oil onto emergent weeds to kill them, replacing hand weeding without herbicides.
Called thermal micro-dosing, this organic farming approved method has been tested in field trials by UC Davis and researched by the University of Bonn.
The Tensorbot has a hybrid power system that comprises a 19kW Winco petrol generator that supplies a LifePo4 battery. Built on a 3.2m wheelbase, the platform has four independently steered wheels, driven by 1.5kW brushless, electric motors, and can turn in its own length.
An on-board camera system identifies weeds against the crop canopy and targets them to centimeter accuracy. This makes this technology particularly suited to working in challenging crops such as organic carrots, high-density leafy greens and onions.
For crops, such as romaine lettuce, thinning, weeding and removing doubles can be performed early, without any soil disruption. Killing weeds while small minimises their impact on crop competition.
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The system uses on-board cameras to identify the weeds, which are then spot sprayed with oilseed rape (Canola) oil heated to 160°C, which kills them.
A universal design, for all planting configurations, allows the same hardware to be used for thinning six-seedline lettuce and weeding 42-seedline baby spinach. With a target operating speed of 2km/h it covers about 0.4ha/hr on a single 80” (3.2m) bed or 1.2ha/hr if deployed on a trailed three-bed implement.
Tensorbot can be used for any liquid crop inputs, from targeted crop protection to minimise pesticide use, to foliar feed and bio-stimulants applied to the plants that need a boost to achieve uniform crop size at harvest time.
Tensorfield will be offering robotic weeding services with a pricing model that scales with weed pressures, ensuring the service is always competitive when compared with hand weeding.