The world’s top banana producer, Chiquita, which grows about one-quarter of all bananas, announced its participation this week in the Better Banana Project, an environmental certification program requiring companies to rein in the use of toxic chemicals, reduce pollution, and conserve soil and water. Chiquita said that it has spent $20 million over the last eight years to comply with the project’s guidelines, but that meeting them will actually help profits because reducing the use of chemicals will cut costs. The company said that all 127 of its farms in Latin America are now certified and its smaller operations in Africa and Asia will meet the program guidelines soon.