DJI has some demonstration of target pesticide spreading drone https://www.youtube.com/watch?v=mfdWYztSqUI https://www.youtube.com/watch?v=mfdWYztSqUI It's not

DJI has some demonstration of target pesticide spreading drone https://www.youtube.com/watch?v=mfdWYztSqUI https://www.youtube.com/watch?v=mfdWYztSqUI It's not as targeted as laser, and it has residual problem, and requires the crop to have resistance, or the pesticide/weedkiller to be specifically targeted. But I think it might be possible to focus sunlight to generate energy to kill weeds, not through battery or generated electricity.