The Wall Street Journal continues their scare-mongering in the 3/11/05 front page story "As Border Tightens, Growers See Threat to 'Winter Salad Bowl'". It's subscriber only, but excerpts are here:

YUMA, Ariz. -- Shortly before Thanksgiving last year, Tom Nassif did something few law-abiding citizens would ever think to do: He called the U.S. Border Patrol here and suggested agents stop manning a highway checkpoint intended to keep illegal immigrants out of the country.

A former U.S. ambassador and currently the president of a powerful farming association, Mr. Nassif told officials that the agency couldn't have picked a worse time to beef up enforcement. Didn't they know it was lettuce season?

The checkpoint -- complete with drug-sniffing dogs -- was meant to stop the flow of illegal immigrants who might have slipped through the regular border controls. But it was also ensnaring busloads of undocumented workers who are critical to the task of picking lettuce and other vegetables during the winter growing season here. Border patrol Public Information Officer Joseph Brigman says he told Mr. Nassif that "we aren't targeting fieldworkers; we're conducting normal operations..."

Later in that thread, someone posts a link to "In Florida Groves, Cheap Labor Means Machines". See also "The Mirage of Mexican Guest Workers".