NOGALES, Ariz. — For the uninitiated, the concept of Mexican-grown produce might conjure up images of unclean fruits and vegetables transported in rickety wagons or beat-up trucks and stored under hot, unsanitary conditions.

That perception, of course, couldn’t be farther from the truth, with many grower-shippers south of the border boasting of fields, cold rooms and trucks that are superior to some of those in the U.S.

Supermarket produce buyers learned long ago that Mexican-grown produce is safe, but still, Nogales shippers must work overtime to let the public know about the stringent growing standards they adhere to.

“We, as importers, have surprised a lot of people,” said Jaime Chamberlain, president of J-C Distributing, the sales arm of Chamberlain Distributing Inc.

“If they went down to Mexico now, a lot of people would be amazed at our farming practices — at how modern they are and how much thought and time gets put into everything.”

“There’s always room for improvement,” he said, “but I’d put our farming practices against anybody’s farming practices.”

Many companies support the produce industry’s Produce Traceability Initiative.

“We are an endorser of the PTI,” said Matt Mandel, systems manager at SunFed.

Steps required by the initiative are in line with goals that SunFed has set to ensure traceability, he said.

But Mandel said he considers food safety at farm level more important than the PTI.

“Traceability is a reactive program,” he said, that’s only important if a food safety problem arises.

“It’s more important to prevent the problem in the first place,” he said.

The company has signed up for the HarvestMark traceability system offered by YottaMark Inc., Redwood City, Calif. It should help SunFed comply with all the PTI requirements and give the firm item-level traceability on honeydews, watermelons, miniature watermelons, cantaloupes and Tuscan-style melons, Mandel said.

The company also recently hired Shay Zeltzer as chief technical officer to develop and monitor food safety protocols and procedures, oversee the team responsible for food safety and quality in Mexico and make sure the company is compliant with the Customs-Trade Partnership Against Terrorism program.

Al Harrison Co. Distributors also has adopted HarvestMark to satisfy PTI requirements and is getting its warehouses certified through, said Brent Harrison, president.

Also, Shelley Harrison-Valdivia, vice president, recently has been placed in charge of the company’s food safety operation.

“It took time, effort and money to get everything up to par,” Brent Harrison said. But once Congress passes food safety legislation, “We’re going to be ahead of it.”

Calavo Growers Inc. also wants to stay on top of food safety, said JJ Badillo, director of diversified products.

“We get to really focus in on that,” he said.

The company is audited by Scientific Certification Systems for good agricultural practices and good manufacturing practices. It’s also involved with the C-TPAT program, has a one-step forward, one-step back traceability program and, in late October, was at milestone three in the Produce Traceability Initiative program.

“We’re continuing to advance,” he said, “making sure our customers and their customers are taken care of.”

Del Campo Supreme Inc. has taken food safety to a level beyond what anyone is asking for, said Jim Cathey, general manager and sales manager.

The company was the first in Mexico to sign on with HarvestMark, and the firm is one of only two companies in Mexico to achieve SQF (Safe Quality Food Institute) 1000 Level 3 certification, he said.

“We feel we’ve done what we had to do to get the interest of major retailers and to show them that we value and desire their business,” he said.