Farm labor (in the USA) has much lower minimum wage and safety protections compared to most other work, enforced by federal law, though I don't know how consequential the farm cost part of the equation is by the time the food gets to the restaurant or dinner table.
Farm labor in the US is largely divorced from the minimum wage because it largely uses undocumented and illegal immigrants, with threat of deportation for any back chat. This was true even in Northern Maine, 2000 miles from the border. These people do NOT make $15 an hour. I don't think they even make $7.25 an hour.
