Other grocery chains have scrambled to adopt similar programs, and food manufacturers have changed formulations and packaging in response to many of those programs. “I think this is going to put pressure on other food retailers to do something in this regard,” said Tom Beddard, an organic farmer who is participating in the Whole Foods program.

Mr. Beddard grows vegetables and melons on a total of some 2,500 acres in Florida, Georgia and Pennsylvania collectively known as Lady Moon Farms. His produce is already certified as organic, and he employs his workers year-round, moving them around the three locations rather than simply to pick a crop. The farms are also certified for food safety practices and fair trade.

Image Credit... Whole Foods Market

He is able to use those certifications to increase his “score” in the Whole Foods program, as well as other practices that he maintains as an organic farmer. But only one Lady Moon Farms earned the “best” designation. “We were a little weak on our use of renewable resources in Georgia and Florida,” Mr. Beddard said.

The program inspired a vigorous discussion at the annual meeting in March of growers for Red Tomato, a nonprofit marketing and distribution platform for small growers, according to John Lyman, one of its members. While the Red Tomato growers have an “eco-certification” program they follow, Mr. Lyman said Whole Foods’ requirements go beyond that into farmworker welfare, conservation, waste reduction and clean energy.

“For instance, they want to know about earthworms and how many I have in my soil,” said Mr. Lyman, whose family has grown apples, peaches, pears and various berries on their farm in Middlefield, Conn., since 1741. “I thought, How do I count every earthworm? It’s going to take a while.”

But he said he welcomed the opportunity to learn from other growers through the program and that it gives a grower like him, whose produce has earned a “good” rating to start, incentives to try out and adopt new practices.