Grower prices for dried plums are on the upswing following a steady decline in statewide acreage, noted industry officials at the South Sacramento Valley prune grower meeting held in Yuba City, Calif. this spring.

The plum acreage has decreased as growers increased acreage planted to more-profitable crops including almonds and walnuts, according to industry sources.

The average grower price for the 2014 crop was “a significant spike over previous years,” said Donn Zea, executive director of the California Dried Plums Board (CDPB) based in Sacramento.

According to the National Agricultural Statistics Service (NASS), the preliminary price for the 2014 crop is $2,200 per ton. NASS’ final price will be released in October.

$2,600 per-ton price

The estimate by the Prune Bargaining Association (PBA) is higher at $2,600 per ton, says PBA General Manager Greg Thompson.

Growers received an average of $2,000 per ton for the 2013 crop.

“The prices which the trade sees as a result of the short crops are not an aberration,” said Zea of the CDPB. “They are prices needed for this industry to continue to produce this great product.”

The CDPB represents 900 dried plum growers and 21 dried plum packers under the auspices of the California Secretary of Food and Agriculture.

California dried plum-acreage totaled about 45,000 acres last year, Zea says, down from about 51,000 acres in 2013. Some plum trees were removed after the 2013 harvest. Statewide acreage has steadily declined since 2001, according to NASS.

“We’ve seen a decrease around the world as well,” Zea said.

In 2014, he says the California dried plum industry produced 97,300 tons, up from 82,311 tons in 2013, but lower than the five-year average of 130,000 tons.

The plum board’s nursery sales survey reported 2014 prune tree sales at about 205,000, down 36 percent from about 320,000 trees the previous year. Nursery sales are expected to increase by 42 percent this year.

Zea believes most new plantings are likely replaced trees.

Export outlook 

Turning to international trade, Zea reports that California dried plum exports are strong. Japan is the top dried plum export destination. Other foreign markets include China, Italy, Japan, Korea, Poland, and the United Kingdom.

California’s newest dried plum export market is South Korea.

The CDPB, in part, funds production research.

Zea noted, “We need varieties which reduce drying and pruning costs, improve the tree’s fruit bearing ability, and enhance fruit quality.”

Current nutrition research focuses on digestive health and bone health.

“We’re talking about digestive health in new ways,” Zea said, emphasizing the role of dried plums in fighting colon cancer.”

Prunes may support healthy bones so we’re building a portfolio of science on the health benefits of prunes,”

Zea said, “We're positioned to take advantage of some great opportunities.”

Plum pox virus

Prune grower Joe Turkovich of Winters, chairman of the CDPB’s subcommittee on research, discussed the plum pox virus and efforts to keep it out of California orchards.

Plum pox virus infects plants of the Prunus genus including plum, cherry, and other stone fruits, plus almonds, wild plum species, and ornamentals.

“It doesn't kill the tree, but it reduces the marketability of the fruit,” Turkovich said.

Transmitted by infected budwood cuttings and aphids, the virus causes blotchy fruit, leaf yellowing, and fruit drop.

Turkovich says there are no effective chemical controls or disease-resistant varieties currently available in California.

“The only cure is to dig out infected trees and the trees around it,” he said.

USDA research suggests a 2,000-foot radius is best to prevent aphids from spreading the disease. 

“The discovery of plum pox virus in California is probably just a matter of time,” Turkovich speculates. “The good news is the virus moves slowly and better phytosanitary controls exist in California compared to other growing areas.”

USDA is exploring methods to prevent and control plum pox virus, including the possible use of canines to detect the disease. In the citrus industry, trained dogs can sniff out citrus canker disease.

Wood rot diseases

Bob Johnson, graduate student with the UC, Davis Pathology Department, reviewed wood rot diseases, and says these diseases can diminish orchard longevity and cause significant yield losses.

Wood rot diseases are difficult to find and hard to control, Johnson says. Research is focusing on disease organism identification and developing techniques for early detection.

“Our ultimate goal is to increase the life of the orchard,” he said.

Jim Adaskaveg, UC Riverside plant pathologist, discussed flower, leaf, and fruit disease control. Fungal diseases include brown rot and rust. He emphasized the importance to rotate fungicides.

“If you use a fungicide exclusively you can end up with resistance,” Adaskaveg said.

Growers should use a spraying program with rotated modes of action, he says.

'Chill portions'

Katherine Pope, UCCE farm advisor in Sacramento, Solano and Yolo counties, discussed 2015 chill hours on dried-plum trees.

“This year, we had an adequate chill followed by early heat so we had an early bloom,” she said.

UC researchers have developed a different way of counting chill hours which Pope says is closer to how the tree actually counts chilling units.

“We call it ‘chill portions’ instead of ‘chill hours.’”

Prune grower Monte Johnson of Johnson Farms in Gridley, who farms with his brother Brad, attended the meeting to stay current on industry issues, including government regulations.

“I'm trying to keep up with things coming down the pike in terms of regulations and nutrients, plus the current trends for prunes.”

Prune grower Todd Ramos of Winters added, “I am very optimistic for the future of prunes in Northern California, based on current grower returns, bearing acreage, a promising outlook in the marketplace, and favorable health research findings.

The meeting was co-sponsored by University of California Cooperative Extension and the Sutter County Agricultural Commissioner’s Office.