Fourth-generation vegetable farmer Will Rousseau keeps one eye on his crops and another on Capitol Hill, where Congress is debating immigration bills that could mean bounty or bust for farms dependent on migrant labor.

Illegal immigrants make up about 53 percent of the nation's roughly 1.8 million farmworkers, and cutting off the flow of willing workers — legal or not — to the fresh fruits and vegetables that need picking would spell the end for many farmers, Rousseau said.

"We know local folks won't take those jobs, at any price," said Rousseau, who hires up to 700 seasonal workers to harvest his crops in Phoenix.

The bills include a House-approved version calling for military enforcement of the border that would make it a felony to be in the country illegally. Rousseau and other farmers believe that would be disastrous for the industry.

On the opposite end of the spectrum, a bill approved by the Senate Judiciary Committee would allow some illegal immigrants to apply for citizenship while expanding an existing but burdensome guest worker program.

Cutting farmers' access to cross-border workers without giving them an alternative could cost the industry up to $9 billion in annual production, according to the American Farm Bureau Federation, which has long lobbied for a streamlined temporary worker program.

The average wage for skilled and unskilled farm workers is about $10 an hour, said Austin Perez, a labor specialist with the federation. If that were raised to $14, up to a third of the nation's fruit and vegetable farms might be forced out of business, he said. And that still might not be enough to recruit large numbers of native-born workers, Perez added.

While a border crackdown is a vision of doom for many farmers, the numbers show consumers wandering supermarket aisles might hardly feel the difference.

That's because very little of the price of produce actually goes back to the farmer. When you take home a $1 head of lettuce, only 19 cents go to the farmer; and six cents of that go to the worker who picked it, according to the U.S. Department of Agriculture.

The real difference would be whether the food is grown in America or abroad. The shift has begun already, as American farmers face steeper labor, fuel and other costs.

For instance, the town of Gilroy, south of San Jose, still calls itself the "Garlic Capital of the World," and anoints an annual Garlic Queen. But China, where production costs are much lower, now grows about 66 percent of the world's garlic, according to the Agriculture Department.

But farmers point to the country's dependence on foreign oil to show the disadvantages of relying on others. Also, food grown at home is fresher, and can be held to American production standards, with stricter environmental and quality control, farmers said.

Fear of an immigration crackdown is already chasing some ag businesses across the border where the workers are, said vegetable harvester and shipper Steve Scaroni.

His company hires 1,500 people in California and Arizona during harvests to pick fresh produce and take it to companies who bag it and give it a brand name. But some of his customers are so concerned that they're shifting their operations to Mexico. And he's following.

"We just don't feel we can risk keeping all our eggs in the USA basket," he said. "We're competing in an international market. It's easy to say, 'raise wages', but the question is, will we stay in business?"

The solution farmers are hoping for — one not promised by any of the current bills — is a program allowing farmers to bring as many workers as they need across the border, without the time or expense of the current guest worker program.

Chalmers Carr, who ships about 1 million boxes of peaches from his 2,500-acre operation in South Carolina, has been using the existing program to bring in up to 300 workers a year from Mexico.

It's expensive — he estimates it costs him about $500 in fees and transportation costs to bring in one worker for one season, not including the mandatory housing expenses. It's also time consuming — in February, he asked for the workers he'd need in April and was still waiting for approval this week.

"This process has to be streamlined, has to work the way it's supposed to if we're going to rely on it," he said. "These proposals fall way short of fixing the problems, but they're a start. It's something."