Weeding a field by hand

Weeding with a short hoe is among the hardest and worst paid jobs in vegetable growing, and it is much of the reason organic lettuce and onions cost what they do. The laser machine covers between half an acre and an acre and a half an hour and is in the hands of more than a hundred growers, which is real but small against the world's weeded ground. It is contested rather than ceded because the machine wants a flat bed, a wide row, a crop it already has a model for, and a tractor of at least 175 horsepower, and very little of the world's farmland matches that description. Weeds close against the plant, in tree crops, on slopes and under cover are still pulled by people, and someone still decides at what point a weed is worth killing at all.