A robot automatically identifies weeds in a field and combats them with a short laser pulse. Sustainable agriculture, which avoids the use of herbicides as far as possible, could benefit from this smart idea.
Read more at: https://phys.org/news/2017-06-combatting-weeds-lasers.html#jCp
the problem is, of course, the cost.
In Asia, the traditional weed control for rice is flooding the rice paddies (you flood the weed out then plant the partially grown rice seedlings in the thick mud).
This, however, produces methane, a greenhouse gas.
Herbicides let you flood the fields less, but to grow organic rice you have to weed by hand, which is labor intensive.
But robots? The cost of a robot is a lot higher than hiring a farmer.