Farmers and allies marched across farmland on the first day of a walk in Pahokee, Florida, to highlight the Fair Food Program, which enlisted food retailers to use their influence with producers to secure better working conditions and higher wages for rural workers.

Farm workers said they were marching to highlight the Fair Food Program, which enlisted companies like McDonald's, Walmart, Taco Bell and Whole Foods to use their influence with producers in an effort to pressure retailers to leverage their buying power to ensure better wages and working conditions. They hoped to use the march to pressure companies like Publix, Wendy's and Kroger to join the program started in 2011.

The march began in the farming community of Pahokee, one of the poorest in Florida, where the median household income is about $30,000. The march's starting point was a camp where rural workers were coerced into working for almost no wages by a contractor who was convicted and sentenced last year to nearly 10 years in prison. The contractor confiscated the Mexican farm workers' passports, demanded exorbitant fees from them and threatened them with deportation or false imprisonment, according to the US Department of Justice.

Protesters were scheduled to arrive on Saturday in the city of Palm Beach, which has an average household income of nearly $169,000 and is home to the mansions of the rich and famous, including billionaire Nelson Peltz, chairman of Wendy's, and former President Donald Trump.

According to the Florida-based Coalition of Immokalee Workers, which organized the march, the Fair Food Program ensured farm workers were paid for the hours they worked; guaranteed them safety measures at work, such as shade, water and access to bathrooms; in addition to reducing threats of sexual assault, harassment and forced labor under armed guards in fields where tomatoes and other crops are harvested.

Wendy's said in a statement that it did not participate in the Fair Food Program because it obtains its tomato supply from hydroponic farms in greenhouses, while the program operates for agricultural workers from outdoor fields, so "there is no nexus between the program and our supply chain". The fast-food chain said it requires third-party reviews to ensure there is no abuse in the picking of suppliers' tomatoes.

"The idea that joining the Fair Food Program and buying field-grown tomatoes is the only way for Wendy's to demonstrate responsibility in our supply chain is not fair," Wendy's said. The coalition described Wendy's response as a "dodge".

Publix and Kroger officials did not respond to e-mailed inquiries.

The idea of lobbying retailers to use their leverage with growers to improve the wages and conditions of Florida tomato pickers began in the early 2000s, when the Coalition of Immokalee Workers led a four-year nationwide boycott of Taco Bell. The boycott ended in 2005 after the company agreed to pay an extra penny per pound for tomatoes purchased from Florida growers in order to raise farm workers' wages.

The Fair Food Program emerged several years later in an agreement with Florida tomato growers with more than a dozen participating companies. Leaders of the Coalition of Immokalee Workers and the Fair Food Program have been recognized with a MacArthur Foundation Fellowship, a Robert F. Kennedy Human Rights Award, and a Presidential Award bestowed by then-Secretary of State John Kerry.

“So now workers have the right to complain without fear of retaliation. Workers also have water and shade as part of these agreements,” said Gerardo Reyes Chávez, a coalition official, at the start of the march in Pahokee. “The program has proven to be the solution, the antidote to the problem of modern day slavery, sexual assault and other problems that have always plagued the agricultural industry.”