I'd forgotten about that selective concept. The flying car analogy is on target. I've been reading about flying cars since I was in Cub Scouts.

I remember that one Corn Belt researcher was playing with the concept of using microwaves to kill seed and/or nematodes in the soil. That was maybe in the mid to late 1980s. I was writing a lot for Soybean Digest. That came to mind today when I saw the new article.

I guess the extension cords weren't long enough for that to be a practical idea. Or the seeds and nematodes were just too deep for the microwaves, kind of like Earl shooting at the Graboids when they were underground (a reference for fans of the movie Tremors).