Swiss company ecorobotix have developed a robot that can micro dose weeds with weedkiller.
The fully autonomous robot is basically a giant solar panel on wheels. It can operate for 12 hours at a time, navigating by GPS along with additional sensors and a camera.
Using two tanks, the robot micro doses the weeds, using 20 times less weed killer than traditional methods.
Now, if the engineers could only make the robot pull out the weeds instead of using chemicals.