[jqm]

In carrots (which are densely planted like four rows to a bed) weeds sometimes do come up in the bed between plants. They usually aren't many because the carrot tops get so dense they smother most weeds out. You can't cultivate those weeds with a tractor (without destroying the carrots) and I don't think they have a roundup resistant carrot. So it's people walking the rows with hoes from what I've seen, or some other herbicide carrots are immune too. The device in the article might be especially good for situations like this.