IMMOKALEE, Fla. -- Tejano music bounced off the one-story buildings of this farming town and the smell of tamales filled the air as scores of revelers danced into the night outside the headquarters of the Coalition of Immokalee Workers.

The celebration marked a hard-fought, unlikely victory by a group of mostly Guatemalan and Mexican tomato pickers over one of the nation's fast-food giants, Taco Bell.

They led a four-year boycott against the chain until it agreed in March to pay a penny more per pound for Florida tomatoes and adopt a code of conduct that would allow Taco Bell to sever ties to suppliers who commit abuses against farmworkers.

With that triumph in hand, the Florida farmworkers group is turning to a larger target: the rest of the fast-food industry. The coalition has sent letters to executives at McDonald's, Subway and Burger King asking them to follow Taco Bell's lead.

"When we started this, it was like man going to the moon -- nobody thought it was possible," said Lucas Benitez, a leader of the coalition. "With the help of people around the country, we have built a way to go to the moon. ... Now we must continue moving forward."

Taco Bell, a subsidiary of Louisville, Ky.-based YUM! Brands, estimates it will pay the Florida tomato growers an extra $100,000, costs that won't be passed on to customers.

The fast-food chain, which buys 10 million pounds of Florida tomatoes each year, also has agreed to help the farmworkers persuade the other fast-food chains, and eventually supermarket retailers, to increase pay and monitor suppliers to make sure farmworkers aren't held against their will, beaten or forced into indentured servitude.

"This is an industrywide approach to get all the growers on board, and then also get all the quick-food restaurants and retail supermarkets to join with us in that effort," said Taco Bell spokeswoman Laurie Schalow.

Whether the other fast-food companies join Taco Bell is questionable, said Mark Sheridan, a restaurant analyst for Johnson Rice Inc. in New Orleans.

"Anytime restaurant companies have permanent increases in the cost of doing business, they tend to pass that along to the consumer through some other efficiency or a raise in the prices," Sheridan said. "I think farmworkers are going to pay more when they eat at Taco Bell."

The extra cost of doing business with Florida growers could eventually force the fast-food companies to look elsewhere to buy tomatoes, said Ray Gilmer, a spokesman for the Florida Fruit & Vegetable Association.

"Then the jobs in Florida are gone," Gilmer said.

McDonald's said it already has a code of conduct for suppliers that prohibits forced labor and child labor, and demands that workers receive fair compensation.

A Burger King spokeswoman said the company's chairman hasn't yet read the coalition's letter, but she noted the chain also has a code of conduct for suppliers.

Subway's spokeswoman said Wednesday the company couldn't immediately comment since it had only received the letter the previous day.

Many farmworkers believe Taco Bell's decision will improve conditions in the fields of southwest Florida, where nearly a third of the nation's tomatoes are grown.

"The victory over Taco Bell is huge," said Domingo Jacinto, a 40-year-old farmworker from Guatemala. "Taco Bell will be able to help us in persuading other companies."

Other farmworkers aren't so sure.

"The reality is it's not going to change our situation, the conditions we live in," said Pedro Morales, a 34-year-old picker from Guatemala.

The Coalition of Immokalee Workers formed a dozen years ago to help increase the wages of the farmworkers, who earn as little as 40 cents for every 32-pound bucket of tomatoes picked, according to the group.

In the late 1990s, the coalition began investigating slavery cases in which farmworkers were beaten and held against their will by labor contractors.

A coalition member, Romeo Ramirez, went undercover to help authorities build a case, taking a job with labor contractors suspected of illegally detaining workers.

The coalition has helped investigate five slavery cases that have gone to trial and currently is in the middle of investigating three new cases in central and north Florida; coalition leaders won't provide details because the cases are ongoing.

Benitez, Ramirez and coalition member Julia Gabriel in 2003 received the Robert F. Kennedy Human Rights Award for their work investigating farmworker slavery.

The coalition turned its attention to Taco Bell in 2001 because of the large amounts of tomatoes bought by the chain and YUM! Brands. The coalition justified a boycott by arguing that the company leveraged its buying power to demand lower prices from tomato suppliers.

The Florida farmworkers held a hunger strike outside Taco Bell headquarters in California in 2003, and last year they protested outside YUM!'s headquarters in Louisville. Celebrities such as actor Martin Sheen joined the boycott, as did the National Council of Churches, the Presbyterian Church (U.S.A) and thousands of students who either got Taco Bell removed or blocked from 22 college and high school campuses.

"We don't like to see even one person out there saying anything negative about our brand," Schalow said. "Certainly, we were anxious to put an end to that."

Farmworkers still have a lot to fight for, Benitez said. They are exempted from federal labor laws that would grant them overtime; they can't organize a union; they don't have health insurance; they live in costly rundown trailers in Immokalee; and many fear losing their jobs for even taking a day off work.

Laws meant to protect farmworkers aren't sufficiently enforced because federal and state agencies that oversee farm labor are understaffed, he said.

"It's not just a problem of the farmworkers in Immokalee. It's not just a problem for immigrant workers in Florida," Benitez said. "The problems in the agriculture industry are problems for all of American society."

On the Net

The Coalition of Immokalee Workers: www.ciw-online.org

YUM! Brands: www.yum.com