Both immigration and wage problems are solved by just using robots. The Lettuce Bot, for example, can "thin" a field of lettuce in the time it takes about 20 workers to do the job by hand.
A new generation of machines targets the last frontier of agricultural mechanization; fruits and vegetables destined for the fresh market, not processing, which have thus far resisted mechanization because they're sensitive to bruising.
And it would solve policy and labor issues too. Bring on the bots!
Robots to revolutionize farming, ease labor woes By Gosia Wozniaka and Terence Chea — The Associated Press