After a contentious battle that included allegations of spying, Burger King announced on Friday that it had reached an agreement to improve the wages and working conditions of tomato pickers in Florida.

At a news conference on Capitol Hill, the hamburger chain, based in Miami, said it would pay tomato prices adequate to give workers a wage increase of 1.5 cents a pound. A penny a pound will go into the workers’ pockets. The extra half-cent is intended to cover additional payroll taxes and administrative costs for tomato growers.

The 1-cent increase means that for every 32-pound bucket of tomatoes they pick, the workers will earn 77 cents, instead of 45 cents. That is a 71 percent increase, the first substantial one in decades for the workers. At the old wage, a farm workers’ group said, the pickers typically earned $10,000 to $12,000 a year.

“If the Florida tomato industry is to be sustainable long term, it must become more socially responsible,” said Amy Wagner, a senior vice president at Burger King. She estimated that the wage boost would cost Burger King about $300,000 a year.