A decision by McDonald's on Monday to pay a penny more per pound for its Florida-grown tomatoes puts the heat on Burger King to do its part to improve the lives of migrant workers. Both fast-food chains had been the subject of campaigns by the Coalition of Immokalee Workers that urged the companies to help guarantee fair wages and working conditions for the laborers who pick the tomatoes in Florida fields... ''Now we are going to focus on the other corporations in the fast-food industry like Burger King and Subway,'' said Lucas Benitez, coalition co-founder and farmworker. [also refers to Taco Bell (part of Yum Brands)]