It's sad to see people defending Mr. No-American-Wants-To-Pick-Lettuce-For-Fifty-Dollars-An-Hour on the charge of being out of touch.
This is the only aspect of John McCain's immigration policy with which I agree -- Americans will not do brute (i.e., non-mechanized) agricultural work for any amount of money.
But, more importantly, why do you care?
You really need to get a reality check.
Its not at all unusual for such work to be done by Americans.
Lots of agriculture relies on teen-agers doing such work during the summer vacation.