McDonald's Corp. (MCD) has agreed to pay a penny more per pound for its Florida-grown tomatoes in an effort to boost wages for the migrant workers who harvest them.

The announcement was made Monday by a Florida farmworker advocacy rights group and the nation's biggest fast-food restaurant chain. Florida pickers harvest about 90 percent of the nation's domestic winter tomato supply.

The deal involves payments for grape tomatoes that go on McDonald's salads.

McDonald's USA spokesman William Whitman said the increase will not be passed along in higher prices for consumers.

Under the agreement, Oak Brook, Ill.-based McDonald's will require its suppliers to follow a workplace code of conduct that the workers would help create. A third party will verify that farmworkers who pick McDonald's tomatoes will receive the increase being paid for the produce by McDonald's.

Farm workers are paid about 40 cents per 32-pound bucket, their representatives say. The extra penny a pound would boost that to about 72 cents a bucket.

The Coalition of Immokalee Workers, representing the migrant workers who harvest Florida tomatoes, had targeted McDonald's in 2005.

The coalition had previously won similar concessions from after a four-year campaign against Taco Bell, which is part of Yum Brands Inc. (YUMM).