There’s a common saying in Georgia about certain blueberry plants that are disease-prone: “They’re plants looking for a place to die.”

MANUEL JIMENEZ, University of California farm advisor, Tulare County, details research he has done on dozens of varieties of blueberries at the Kearney Agricultural Research and Extension Center in Parlier, Calif.

That expression is even more appropriate for blueberry plants in California, says Manuel Jimenez, University of California Cooperative Extension farm advisor in Tulare County.

Higher pH levels, along with higher land prices, present even greater challenges to the state’s growers, he said. And their very successes – and those of other growers worldwide – are now starting to haunt them as worldwide production of blueberries booms and prices to growers decline.

Exploding production and shared information on how to lower pH levels were among topics for a field day that Jimenez coordinated at the UC Kearney Agricultural Research and Extension Center in Parlier, Calif. The day before, Jimenez led growers and others on a tour of blueberry farms in the central San Joaquin Valley.

Farms they visited included acreage owned by the Willems family, which farms in the Reedley, Dinuba and Kingsburg area. Greg Willems talked of the need to micromanage fields and the differences in soils.

Willems acknowledged prices being paid to California farmers for their blueberries are down this year, dropping to about $2.10 a pound from $3.30 a pound last year in his case.

“There are too many acres,” he said. “It’s overdone. When I started seven years ago, it was $6.50 a pound.”

But Willems and others are not despairing. He believes the hundreds of acres his family farms – and the diligence they apply – will maintain blueberries as a viable crop in pH-challenged California.

And the field day that followed was loaded with information on staying alive in the face of competition and efforts by the blueberry industry to bolster consumption with steps ranging from sales for pet food and feed for thoroughbred horses to use in cosmetics – not to mention trying to double America’s per capita consumption by 2015.

“We’ve been surfing the blue wave,” said Mark Villata, executive director of the U.S. Highbush Blueberry Council in Folsom. “Now it’s starting to crest.”

Villata cited an effort called Blueprint2015 to increase demand for blueberries in the face of increased production. He pointed out that increased interest in blueberries among health-conscious consumers, as well as growers, has led to increased acreage in North America – up 33 percent in the past three years.

North American production has more than doubled in the past 10 years to 407 million pounds, he said. Worldwide supply could exceed 1.5 billion pounds by 2015. And the fruit prized for its health benefits is facing stiff competition from other fruits high in antioxidants, including cranberries, plums and pomegranates.

“We were the media darlings, but we’re not alone (now),” Villata said.

Villata said his organization is looking to increase assessment rates for growers to pay for stepped-up promotion, research programs and media outreach.

The blueberry council has voted to increase the assessment rate for the first time since 2001 when the council was first established. The assessment rate will go from 0.6 cents per pound ($12 per ton) to 1.2 cents per pound ($24 per ton). The assessment increase must go through rulemaking before taking effect, and it could be put in place on 2010 production.

Villata believes there are “undeveloped domestic markets” and that a growing middle class in countries such as India could open the way to more exports. Only 3 percent of the U.S. Highbrush crop was shipped offshore in 2008.

Villata said more than 1,400 new blueberry products were introduced in North America in 2008.

Jimenez said he was concerned about the jump in California blueberry acreage “to close to 5,000 acres” in just a few years. When he and others visited an Exeter packinghouse where 2-pound boxes of blueberries were being packed just days into the harvest, he said he was “shocked.”

“At this point, so early in the season, it would be more common to be packing 4-ounce clamshells that would have been selling for $3 to $4 each in stores,” he said.

The packinghouse is operated by the Lagomarsino Group, a Visalia-based enterprise that farms a diverse range of crops, including blueberries.

In a blueberry field near Tulare, Lagomarsino’s director of farming, Steve “Doc” Blizzard, and the company’s farm manager, Blake Ueki, discussed their operation.

Blizzard talked of “a steep learning curve,” which included the realization of harm that could be done by over-watering. Asked how high the berry bushes should be, he told his 6-foot tall questioner, “Not much taller than you are.”

This year, an ill-timed spring frost hit the Lagomarsino blueberries, killing some of the lead berries. But ample berries remain, and crews of six or so workers per acre toiled to bring in the harvest that will involve seven or eight sweeps through the field.

As they worked, a bird cannon sounded and recordings of birds in distress were played to keep birds from conducting their own harvest.

The workers will balance their time for now between fresh cherries and the blueberries, then move into the grapes.

“You have to have a lot of people this time of year,” Blizzard said.

Ueki talked of the challenge of adding sulfuric and other products to lower soil pH levels.

“You have to keep it low,” he said.

Ueki said Lagomarsino, like most growers, adds new mulch every other year, choosing materials that might lower pH levels. He said 100 cubic yards per acre is added at a cost of up to $1,000 per yard.

During a visit to the Exeter packinghouse, Jimenez said a single line for packing can cost at least $300,000. The lines commonly sort for size and color. Some may sort for firmness. A berry that is too soft can cause problems during shipping.

At the Kearney center, there are 70 varieties under cultivation. Only a half dozen of them – including Jewel, Emerald and Star – comprise most of the varieties grown for commercial production.

Emerald and Star account for about 75 percent of the state’s production.

Dave Brazelton, president of Fallcreek Farm and Nursery in Lowell, Ore., talked of the merits and disadvantages of various varieties.

“The flavor is a little tart,” Brazelton said of the Star. “They can be a little soft, but firm well in cold storage. They’re one of the workhorses.”

As to the Emerald, Brazelton said, “Very early bloom can get frosted.” They also have tight clusters that make them tougher to pick, he said.

Field day participants heard about production costs in the San Joaquin Valley from Tom Avinelis, a Strathmore grower of blueberries since the mid-1990s.

“We’re among the pioneers, and you can tell by the arrows in our backs,” he said.

Avinelis called blueberries “the most challenging crop for California.” He said the cost for starting production – not counting land cost – in the San Joaquin can be between $11,000 and $20,000 per acre. Major costs include acidification of the soil, mulching, irrigation systems, fumigation and the plants themselves.

“You can change the face of the earth, but it’s best to choose your site carefully,” he said.

Because production can be so great, he said, there’s a tendency to over-crop to recover costs. That has some worried about the longevity of plantings, and when they will need to be replaced.

He said frost is “a risk that is substantial.”

Avinelis said packing equipment can range from $150,000 to more than 1 million dollars for just one line. But he believes production works best under an integrated arrangement where the grower controls the packing. The year-to-year production cost, he said, can be between $2,500 and $4,500 per acre.

Mechanical harvesting is happening in some blueberry fields, and Frank Brown, production manager with Littau Harvester in Stayton, Ore., said harvesting equipment can be leased for between $20,000 and $36,000.

Littau hopes to conduct a field day in the Valley to showcase equipment.

Brown said mechanical harvesting can be done only on the coolest part of the day in the Valley, starting at 4 a.m. and stopping by noon. The idea is to chill the blueberries as quickly as possible after picking.

The Jewel variety is a challenge for mechanical harvesting, he said. “You can’t pry one out of there,” Brown said.

David Haviland, UC entomology farm adviser for Kern County, says California growers do not have to deal with the blueberry maggot.

Other pests, however, including citrus thrips can be controlled by avoiding more susceptible varieties – “Stars are thrip magnets,” he said. Insecticides like Success, Delegate and Entrust and Assail can control thrips.

Oils, soaps and pyrethroids do not control citrus thrips, Haviland said.

Grubs like those commonly found in lawns can also be a problem.

“To a grub, a blueberry field probably looks and feels like a lawn,” Haviland said of the pest that can stunt and kill young plants.

Among solutions being studied is the use of parasitic nematodes as a biological control.

Baldev “David” Munger, a member of a farming family that is a major grower of blueberries in California, was particularly interested in use of the nematodes that can be delivered to soil through irrigation lines.

He looked at microscopic displays of the nematode in action on the grubs, an exhibit provided by Koppert Biological Systems Inc. in Watsonville.

But Haviland said there are still questions about how effective the nematodes are. Unknowns include the rate needed, the effect on mortality, the effects on fecundity as well as on secondary infection and feeding.

Munger said the field day and tour were valuable, “just to see what the industry has, what it is doing.”