There's absolutely no reason to do something peacefully and by hand when you could do it violently, with lasers, instead. Germany agrees, and scientists there are developing a system that replaces the task of pulling weeds with a system of plant-pulverizing semi-autonomous laser cannons.
A research group at Leibniz University in Hannover has decided that herbicides are a bad idea. Chemical weed control is expensive, and it in a shocking turn of events it involves chemicals, some of which may not be especially good for you. Organic and herbicide-free is the way to go, but plucking weeds by hand is literally a pain, so the researchers have come up with an overhead laser system instead.
The system relies on an array of overhad cameras that use fancy algorithms to separate good plants from bad. Once the bad plants are identified, their most vulnerable spots are targeted (based on species and maturity), and then they get torched by a powerful CO2 laser. This is harder to do than it might seem, since using the wrong power or wavelength can actually stimulate weed growth, which seems like a good thing to know if you're a budding evil genius without much ambition.
Deployment of this system in the short term will likely involve overhead tracks in greenhouses and nurseries, where the cameras and lasers can easily move around and get a good view of the battleground. Long term, the researchers are picturing small laser-equipped robots flying in swarms over outdoor fields, blasting away at weeds, small animals, large animals, and anything else that they deem threatening to the crops inside their engagement zone, including (we have to assume) hungry humans.