AURORA, Ore. — Farmer wisdom on blackberry maintenance — or the lack thereof — is being backed with evidence.

Many growers are turning to “new-over-old” primocane management instead of traditional August pruning. New vines simply get tossed over the existing canopy without any thinning or bundling at the bottom.

“We have some growers that have been doing this for a decade, maybe 15 years,” said Amanda Davis, a berry researcher at Oregon State University’s North Willamette Research and Extension Center.

A study showed the practice reduces labor by 80-90% and potentially increases yield and berry size.

“New-over-old is going to save you a lot of money,” Davis said.

Worries about disease, insects

Davis gave a presentation at OSU’s annual Caneberry Field Day on June 26. About 50 people attended.

Trials were conducted on machine harvested rows of Columbia Star, designed as a Marionberry replacement and released by OSU in 2013. Columbia Star now accounts for a third of Oregon’s blackberry acreage.

A more thorough economic analysis of new-over-old will be conducted after this year’s harvest.

Davis said worries such as disease and insect pressure also will be looked at more closely.

“We have not seen differences that are big enough to be concerned,” Davis said.

The yield remains higher even with a higher sort out.

Stronger trellises may be needed to accommodate extra weight with new-over-old. But the shade provided by messier rows may shield berries during hot weather.

Parasitoid wasps winning

OSU graduate student Ho Jung Yoon said a parasitoid Korean wasp was “winning the battle” against spotted wing drosophila in caneberry and blueberry fields.

A generalist parasite wasn’t successful against the invasive fly, which can produce 30 generations in a year.

Conventional pesticides also are becoming less effective against SWD.

The imported wasps — it took 10 years to secure a permit — were establishing well at test farms, Yoon said.

She added the next step will be commercialization.

Other presentations at OSU’s Caneberry Field Day focused on blackberry water demands, increasing calcium in berries, pesticides and caneberry breeding.

Blackberry data

Blackberry production in Oregon has stayed flat the last two years at about 35 million pounds, said Darcy Kochis, Oregon Raspberry and Blackberry Commission administrator and marketing director.

The 2021 harvest was about 22 million pounds due to a record-breaking heat wave, Kochis added in an email.

About 95% of Oregon’s crop is processed or frozen and the state ranks No. 1 in the nation in processed blackberry production.

According to the USDA Census of Agriculture, Oregon had 5,247 acres of blackberries in 2022, down 17.8% from 2017. Oregon’s raspberry acreage also declined, dropping 32.2% to 1,821 acres.

Season delayed

Blackberry harvest was getting underway the last week of June.

Berry season overall looked slightly delayed due to cool weather for Oregon, Washington and British Columbia, said Julie Pond, executive director of the Northwest Berry Foundation.

“Everyone is just holding onto hope that yield will make up for another year of not-so-great prices,” Pond wrote, in the organization’s weekly newsletter.

More berry coverage

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Oregon’s strawberry industry continues to shrink

California’s strawberry crop looking strong this year

Blueberry council hopes to get a boost from pro pickleball

Northwest blueberry industry hopes for rebound

National $4 million study to focus on blueberry rot