A new pest has burst on the scene at Oregon State University’s North Willamette Research and Extension Center.
Rose stem girdler, a small, metallic beetle that bores into raspberry and blackberry canes, was discovered last year at the station, prompting faculty to come up with a plan of attack to control the damaging insects.
With reports of rose stem girdler in cane fruit on the rise across the Willamette Valley and southwest Washington, researchers discussed the latest infestation during Caneberry Field Day Wednesday at the station in Aurora, Ore.
Patrick Jones, faculty research assistant, said the problem first arose in late July and early August last season, when they noticed wilting among the tops of blackberry and raspberry plants.
Typically, Jones said the plants will die all the way down the crown if there is an issue with root rot or general health. These canes, however, were snapping around the middle.
“That was the big tell that we had a new pest problem,” he said.
Jones figures rose stem girdler was present at the station for years, but last year they did not conduct early season spraying for spotted wing drosophila, which may have allowed the beetle population to explode.
“It was just kind of a fluke year,” he said. “At least it’s on everybody’s radar now.”
In response, the station began spraying pesticides to control rose stem girdler, based on a 2015 Utah State University Extension report. While it is still tell, Jones said he is optimistic the results will be positive.
“I think we’ll do better than last year,” he said.
About 50 growers attended Caneberry Field Day, which featured updates on field trials for new varieties of blackberries and raspberries, along with presentations on pest and weed control.
Oregon produced 42 million pounds of cane fruit in 2017-18, according to the state Raspberry and Blackberry Commission. Those numbers were down from 59 million pounds in 2016-17, though Bernadine Strik, berry crop specialist for OSU, said part of that is due to growers tearing out older varieties of blackberries to replace with newer ones more highly sought by processors — namely Black Diamond and Columbia Star.
Together, Black Diamond and Columbia Star accounted for more than 70 percent of plant sales in Oregon in 2017. The next closest was Marionberry, at just more than 8 percent.
As for raspberries, Tom Peerbolt, director of the Northwest Berry Foundation, said he is excited about several new varieties in development that he hopes will break through the “bottleneck” currently facing growers.
Oregon grew roughly 4.5 million pounds of red and black raspberries last year, with 72 percent of sales from just four varieties: Cascade Delight, Cascade Harvest, Cascade Gold and Meeker.
Peerbolt said he is particularly enthused about Cascade Premier, a just-released variety from Washington State University.
“I think these guys really have potential to be grown here economically in heavier soils,” Peerbolt said. “If we can help accelerate that even a year or two, it could really help growers out there, and the industry as a whole.”