(May 23, 2:39 p.m.) The produce department is becoming an increasingly expensive section of the grocery store.

The average price of produce at the retail level has swelled nearly 5% since last year, with certain commodities experiencing double digit growth, according to research provided by The Perishables Group and powered by ACNielsen Co.

Fruit and vegetable prices typically escalate about 2% each year, so 5% is a significantly higher spike, but not particularly surprising, considering rising input costs and the erratic weather that has plagued certain crops in recent years, said Steve Lutz, executive vice president of West Dundee, Ill.-based The Perishables Group.

“You’re always going to see a variation in year-to-year prices, just based on supply conditions, availability and quality,” Lutz said. “The broader question is, when you look at the entire basket and total produce is up, it’s pretty rare to have everything in short supply year after year. My guess is what you’re seeing is higher input costs, whether on the farm, or whether it’s diesel.”

Items with most extreme price increases: avocados at 20%, melons at 13%, onions at 12% and citrus at 11%, according to the research, which was based on dollar performance for all random weight and UPC items for the year ending in March.

Peppers increased only 0.2%, followed by potatoes at 0.9%, lettuce at 1% and bagged salad at 1.4%.

So why such a small price change for an item like bagged salad?

It’s difficult to say, but it likely can be equated to its widespread popularity, which creates competitive pricing among retailers, Lutz said.

“Within packaged salads, consumers have a lot more switching options,” Lutz said.

Karen Peterson, corporate communications manager for Charlotte, N.C.-based Bloom grocery stores, said, indeed, prices are rising at the retail level, but Bloom, which is owned by Salisbury, N.C.-based Food Lion LLC, is striving to keep its produce prices competitive and has yet to see a downturn in sales.

“People are still buying,” Peterson said. “What you may be seeing is that people will eat at home more, so they may actually be shopping at the grocery store more.”

Dominic Palazzolo, buyer and supervisor for Southfield, Mich.-based Hiller’s Markets, said he couldn’t relate to the higher prices because Hiller’s seven stores have not upped their prices during the course of the year.

Rob Wedin, vice president of sales and marketing for Calavo Growers Inc., Santa Paula, Calif., said the avocado price surge is due to a variety of factors in the Chilean, Mexican and California growing regions, including demand that outpaces supply, lower supplies caused by volatile weather (freezes and fires) and the devalued American dollar, which creates a more attractive European market.

“The consumption of avocados has been growing at 15% a year through 2006 for the past four years, and the supplies of avocados in the U.S. were matching that demand,” Wedin said. “But then the freeze happened in the winter of 2007 (in California), followed six months later by a freeze in Chile.”

The wildfires that swept through California in November 2007 wiped out some avocado production, but it’s predominantly the January 2007 freeze in California hurting the state’s production, as avocado trees typically take around two years to begin producing again, Wedin said.

Additionally, the Mexican avocado crop could be down this year due to weather, and Chile should have a light crop, he said.

Richard Pazderski, salesman for Glennville, Ga.-based Bland Farms LLC, said the swelling onion prices could be connected to high transportation costs, but he was somewhat unsure, as there has been no major spike in onion prices at the wholesale level.

Bland Farms, however, always encourages retailers to lower prices to alleviate pressure on the consumer and supplier, Pazderski said.

“We’d like to see competitive prices to help us,” Pazderski said.