Here in Kansas farmers have been hiring foreigners to help with the wheat harvest for years. They hire legal temporary workers, but they are operating farm equipment rather than picking by hand as is the case of apples. If the federal government had any sense it approve bringing in legal temporary workers to harvest apples and other crops too.
I fell for that one too when our local strawberry farm was defending hiring "legal" temporary workers. In a recent article, they were complaining about the government crackdown, because they have "a lot of names that don't match up with the social security numbers". That told me all I needed to know -- they knew all along that many (if not most) of their workers were illegal aliens.
There’s already a legal means to do that, but it brings responsibilities and expenses to the employer that they would rather not have.