MOUNT SHASTA, Calif. — Mark Derby, who operated a produce distribution warehouse in Mount Shasta, until he sold it to General Produce Co., Sacramento, in 1986, has seen the Northern California produce distribution landscape evolve over the years.

Retail chains, such as Lucky/SaveMart, Safeway and Raley’s/Nob Hill/Bel Air, have been joined more recently by the likes of Dollar General Market, Walmart Neighborhood Market, Fresh & Easy and Sunflower Markets/Sprouts.

The retail sector is even more crowded as discounters such as Wal-Mart and Target and club stores have begun selling produce.

“It’s a much more competitive field,” said Derby, who is general manager of the General Produce Mount Shasta facility as well as director of procurement for the company.

“There’s pressure on our margins, and it seems like we have to do more with less.”

At the same time, Northern California has weathered the recession, with some areas being hit harder by foreclosures, business closures and layoffs than others.

In those regions, restaurants and other eateries have felt the effects of fewer customers and less overall revenue.

“We’ve had some credit exposure,” Derby said.

“We’ve had some customers not go out of business, but get out of business. We’ve had old-time businesses that said basically, ‘We’re done.’ But we’re still going at a pretty good clip.”

Derby attributed part of that to decisions made decades ago to expand from strictly retail accounts into foodservice and exports.

Now foodservice ― which ranges from restaurants and schools to hospitals and military commissaries ― comprises about a third of General Produce’s business.

The 78-year-old company serves an area stretching from Visalia north to southern Oregon, and from the Pacific Ocean east to Reno, Nev. In fact, Derby said, more than half of their business comes from southern Oregon.

General Produce also handles a wide variety of produce ― conventionally and organically grown ― as well as other items such as fresh and bottled juices, eggs, floral products and snacks.

The mix has evolved over the years to meet changing food trends.

Foods such as blueberries, kale and avocados are in high demand now as consumers heed the advice to eat healthier, Derby said.

“We couldn’t even have dreamed of selling things like kale, but superfoods are getting a lot of play,” he said.

“I think consumption has picked up.”

Derby said he’s also seen more interest in locally grown product, citing heirloom tomatoes as one of their hot sellers.

One of the challenges with operating a fleet of trucks in Northern California is the rising cost of fuel, which often spikes when a refinery shuts down unexpectedly.

The company has invested in computer software that picks the most fuel-efficient routes for the trucks.