If you paid a decent wage and it was year-round work, you should have no problem finding American workers to do that type of work. So, would you care to tell us how much you pay your workers, and is it year-round work?
Grapefruit/citrus is harvested once a year. It is seasonal work, other than disking the orchard of weeds and spraying for critters a couple of times a year.
I discussed pay and made an offer earlier that was not accepted. The contract has therefore returned to its former obligee. Thank you for inquiring.