DENVER (AP) — Federal regulators and state inspectors have issued warnings to cantaloupe farmers and packers that they will be testing melons for pathogens this year after two years of illness and recalls in the industry.

A 2011 listeria outbreak traced to Colorado's Jensen Farms killed 33 people. Another outbreak last year was traced to salmonella at an Indiana cantaloupe packer.

The warnings are being issued before this year's growing season to make sure this is a safe year for consumers.

"It is essential that those involved in growing, harvesting and distributing cantaloupe and produce in general follow agricultural practices that the FDA and the produce industry have identified as effective in minimizing the risk of contamination," said Michael M. Landa, director of the Center for Food Safety and Applied Nutrition at the FDA.

Michael Hirakata, head of sales for Hirakata Farms and chairman of the Rocky Ford Growers Association in southeastern Colorado, which has more than a dozen members, said Tuesday he spent about $50,000 last year for government and independent inspections of his field and processing facilities. He said it is money well spent to reassure the public that cantaloupes are safe.

Hirakata said many grocery stores and retailers are now requiring growers to hire independent contractors to review safety procedures, in addition to the federal and state inspections, to protect their reputations and their customers.

"We have to do this," Hirakata said.

Cantaloupe growers in Rocky Ford were hit hard by the 2011 listeria outbreak, even though the contamination occurred 90 miles away.

Since then, they have been working hard to restore confidence in their product. Farmers there have spent nearly $1 million on safety upgrades for melon production.

There is also a movement to require stronger oversight of third-party auditors because of questions raised by the Jensen Farms outbreak, which passed an independent inspection shortly before the listeria outbreak.

Most farms and food facilities are only checked by the FDA every five or 10 years, though a new food safety law aims to increase the frequency of inspections. To target an entire industry like cantaloupe is rare but not unprecedented — the FDA said it would do new inspections of all of the nation's largest egg farms after hundreds of people were sickened by salmonella in eggs in 2010.

Just since last summer, outbreaks of listeria in cheese and salmonella in peanut butter, mangoes and cantaloupe have been linked to more than 400 illnesses and as many as seven deaths, according to the federal Centers for Disease Control and Prevention.

Proposed new rules for all produce introduced earlier this year would require farmers to take new precautions against contamination, to include making sure workers' hands are washed, irrigation water is clean, and that animals stay out of fields. Food manufacturers will have to submit food safety plans to the government to show they are keeping their operations clean.

It could take the agency another year to craft the more stringent rules after a four-month comment period, and farms would have at least two years to comply. That means the new rules are at least three years away from taking effect. Smaller farms would have even longer to comply.