But now start-up Blue River Technology is developing a weed-seeking robot. For the past few years, Blue River Technology has been working on what they call 'organic weed elimination'. Instead of relying on herbicides, the company envisions flocks of autonomous robots that could be programmed to travel up and down crop rows, removing weeds by 'hand'. Once it hunts down a weed, the bot injects enough fertiliser to kill it.

So far, the company has produced a few prototypes. The rolling robot uses computer vision technology to evaluate the plants as it passes by, using algorithms to detect and differentiate between plants that are right next to each other.