Wal-Mart, Kroger and Meijer said Friday they are suspending business with a large southwestern Michigan blueberry grower after investigators found children as young as 6 working in the grower’s fields.The retailers said, pending further information, they have stopped buying products from Adkin Blue Ribbon Blueberry Co. near South Haven, about 45 miles southwest of Grand Rapids.Michigan is the nation’s largest blueberry producer, with 110 million pounds harvested in 2008. New Jersey was second last year at 42 million pounds.The U.S. Department of Labor announced this week a check of 35 randomly selected farms in Michigan led to eight of them being fined about $36,000 in all for violating federal migrant-housing and child-labor laws.Ten other farms were cited for violations but not fined. Adkin was the lone farm fined for both migrant-housing and child-labor law violations and paid more than $5,500 in penalties, said Scott Allen, a Labor Department spokesman based in Chicago.Adkin general manager Tony Marr said the company has a strictly enforced written policy prohibiting young children from working in its fields. Adkin is conducting its own investigation to determine how it happened, he said.“We certainly don’t condone or promote child labor here in any way,” Marr said.The company has eight full-time employees and hires about 350 seasonal workers each year to harvest and process the blueberries grown on its 640 acres.Labor Department investigators found four children working in Adkin’s fields during an unannounced visit on July 8. At least two of the children were younger than 12, including the 6-year-old.“There are regulations and laws against child labor for a reason — obviously, to protect these children,” Allen said.During inspections throughout the state, investigators found workers living in unlicensed migrant labor camps with sewage from a faulty septic system seeping up near living units. They also discovered untreated waste water spilling out of broken pipes, no hot water for hand washing and infestations of bugs and rodents.