AURORA, Ore. — Dozens of people sporting hats and sunglasses taste-tested berry varieties and licked blueberry popsicles while listening to scientists from Oregon State University, USDA and other institutions talk about new research at OSU’s Blueberry Field Day last week.
The findings, presented at the North Willamette Research and Extension Center, could help growers.
One recent study, led by USDA researchers David Bryla and Scott Orr, found that applying calcium to soil can affect yield and quality.
“Calcium impacts fruit quality,” said Bryla.
If applied properly, the researchers found that calcium can improve fruit firmness and extend berries’ shelf life.
In a separate, ongoing study, OSU faculty research assistant Amanda Davis and co-researchers aim to answer a popular question growers ask: Does adding humic acid to a regular fertilizer program improve soil quality and yield in mature blueberries? Trials to answer this started in 2021, and researchers expect results in 2023.
A new pesticide for blueberries may be in the pipeline. According to Dani Lightle, OSU pesticide registration research leader, the EPA soon plans to evaluate Applaud Insect Growth Regulator, a product that targets mealybugs and other pests, for use in blueberries.
The industry is also turning to biological controls.
An invasive fruit fly — the spotted wing drosophila — affecting Northwest blueberries may meet its match in a tiny parasitoid wasp called Ganaspis brasiliensis.
This summer, OSU has been releasing the beneficial wasps near farms across Oregon in hopes that the wasps will control the spotted wing drosophila.
Rearing and releasing the wasps, however, takes time.
“The wasps are rather high maintenance, so it’s been a learning curve,” said Jana Lee, research entomologist for USDA’s Horticultural Crops Research Unit.
Jesse Carroll, a graduate student at OSU, recently worked with Bryla, of USDA, to test pulsed irrigation — the practice of applying water in short intervals each day — in blueberries.
Carroll’s initial study found that pulsing water can significantly increase yield and berry size.
“The pulsed drip irrigation method seemed to be promising,” said Carroll.
Further research is needed.
Pruning and trellising
Pruning and trellising practices can significantly impact yield, according to results from a six-year trial led by Davis, the faculty research assistant, and Bernadine Strik, recently retired from leading the berry research program at OSU’s North Willamette Research and Extension Center.
The trial in Legacy and Mini Blues varieties found that pruning and trellising according to recommended methods can improve fruit quantity and quality. Although pruning demands more labor, the higher labor cost was outweighed by higher yield.
The Vaccinium Coordinated Agricultural Project, a USDA-funded project led by researchers from around the world, is developing new genetic tools to enhance breeding of blueberries.
USDA is similarly evaluating the potential of genetic markers for predicting fruit quality and ripening season.
Oregon’s blueberry industry also has a new research leader.
Strik, who had led the berry research program since 1992 before retiring this winter, has passed on her position to OSU horticultural expert Scott Lukas, who is transitioning into his new role.
“The program is in fantastic hands,” said Strik.