[BurningFrog]

This will create weed breeds that look more and more indistinguishable from the crops.

[a_bonobo]

Funny enough, this has may have already happened - Darnel was probably domesticated around the same time as wheat, and now it looks pretty much like wheat. There's a chance that humans accidentally swept it up when they domesticated wheat. The problem is that Darnel is psychotoxic and ingestion in the worst case can lead to a coma.

Possibly locked review: http://link.springer.com/chapter/10.1007%2F978-3-642-13145-5...

[ars]

To get "more and more" you have to have a weed that triggers a partial response from the machine.

This works with a chemical - i.e. an accidental low dose, but I don't see how that would happen with this machine.

If, you had a weed that was so close to the crop it was only sometimes recognized then yes, but weeds mostly look nothing at all like the crop.