By Mary Stewart, OSU Extension Regional Communications & Marketing Coordinator, West Central Region.
Blueberries. Farmers call them “nature’s candy,” nutritionists call them “superfoods,” and consumers here and around the world call them a staple in their daily diets.
The delectable sapphire-blue fruits are ripe and ready for harvest now. The long growing season ends with frost in October. The commercial crop is grown by the acre-full in and around Salem and across the milder growing climates of Oregon.
“Consumers want healthy food that is affordable. Anything that improves yields, quality, grower profitability and increases locally-grown produce, benefits consumers,” says Dr. Bernadine Strik, Extension berry specialist based in the Department of Horticulture at Oregon State University and at the North Willamette Research and Extension Center (NWREC) in Aurora and the university’s lead blueberry researcher.
“Blueberries are the most rapidly-growing berry crop in Oregon by far,” “We have more than 8,000 acres harvested in Oregon and considerably more than that planted for producing in the future.” Blueberries make up one-third of the 23,000 acres of Oregon farmland planted in berries.
The growing conditions in Marion County are ideal for blueberry production because of the fertile, naturally-acidic soils, climate, and a partnership of skilled farmers and university researchers who keep finding better ways to grow more and better berries in order to help farmers stay competitive on the world blueberry market.
Steve Erickson, CEO of Pan American Berry Growers in Salem, says, “There are only a couple of areas in the world that have the possibility of growing blueberries as well as we can here in the northwest.” Compared to California, summers in Marion County are moderate with an average day temperature of 85 degrees and cool nights. “Because it takes longer for blueberries to ripen here, we have a better chance for good sizing and higher Brix, which is the sugar content,” he explains.
Since consumers in Marion County can’t consume all the fruit the prolific bushes can yield, and because of the tremendous global demand, Pan American Berry Growers pick, pack, and ship Marion County blueberries worldwide, including exports to Japan, Taiwan, and Korea.
“Right from the beginning, we wanted to be the best we could be at growing and packing high-quality blueberries,” says Erickson. Pan American Berry Growers, formerly VanCleave Farms, is one of the largest blueberry operations in Marion County. The vertically-integrated farm provides hundreds of seasonal jobs and annually contributes several million dollars into the local economy. “Our focus has been late season production, but we know that we must have fruit in every marketing window,” Erickson explains. Pan American markets their berries through Naturipe Farms – the world’s largest marketer of fresh blueberries.
In order to keep his blueberries the cream of the crop, Erickson and his business partners recognized the importance of conducting scientific research to improve blueberry quality and production. For decades, Erickson and other blueberry farmers and the Oregon Department of Agriculture’s Oregon Blueberry Commission have collaborated with researchers from Oregon State University (OSU), USDA-ARS in Corvallis, and Washington State University (WSU).
OSU has conducted multi-year studies on plant nutrition; organic production; IPM insect and weed pest management and new berry variety development. “Ken Brown from the Marion County office of OSU Extension (now retired) was the first one to get us started in cooperative blueberry research. We have always had the attitude that it is a privilege to participate in research with the Universities. We feel an obligation to participate with the universities, and cooperatively, help further the Northwest Blueberry Industry,” Erickson explains.
The agricultural research process is best conducted as a partnership, where some types of trials are conducted in the controlled environment of the North Willamette Research and Extension Center and other types of trials conducted on a working farm.
“Erickson and the other blueberry growers here are fabulous,” says Strik. “They realize that the result of the research benefits everyone, they follow good management practices, they grow quality fruit and they allow us to come on their farms to conduct research,” she explains.
“In the applied research programs and extension programs, we work with growers to improve the industry and move it forward,” says Strik. “We are always looking for ways to make growers more economically sustainable,” she adds.
Forty years ago, farmers had limited choices of blueberry varieties to grow commercially. Today, because of advanced breeding programs, growers have many varieties to choose from. For instance, Fall Creek Farm & Nursery obtained the rights to sell three new varieties released from Michigan State University--Draper, Liberty and Aurora. According to Erickson, “the new varieties have really changed things in Oregon.”
In order to test the potential for success in local fields, Strik and Dr. Chad Finn, the USDA-ARS berry crop breeder planted the new blueberry varieties at NWREC, including many varieties that were so new they were identified only by a number.
Today, there are many public and private breeding programs that are beginning to release new blueberry varieties. “Planting the new varieties can be big risk for growers as the varieties are often being developed outside of Oregon in much different growing conditions,” says Erickson. Fortunately, new varieties have performed very well in Oregon’s Willamette Valley, one of the world’s premier blueberry growing regions.
In 2005, Bernadine Strik began a series of research projects on Pan American Berry Growers’ farm near Salem.
Strik’s initial research trial determined if plastic growing tubes placed at the base of newly-planted blueberry bushes would improve growth. Many growers in eastern Oregon and Washington were using the technique but without any scientific proof. The theory was that the tubes would protect the bushes from rodents and the elements, encourage rapid vertical growth, and keep a tighter stem base for machine-picked fields.
After a three-year trial, sample bushes were dug up and examined. The results were not impressive. In fact, the research showed that while the tube made the plant more vertical, it reduced root growth.
We learned something different than what we thought we would learn, but either way, we learned something valuable, and in this case, a technique that should not be used,” says Erickson. When the research results were reported by Strik, most all growers stopped using the tubes.
Just like humans, blueberry plants need balanced nutrition in order to grow well and produce high-quality fruit. Farmers feed fertilizer to provide plants with the nutrients they need at precisely-planned times.
Growers have changed the amount of nitrogen fertilizer applied and have better-timed fertilizer applications to provide fertilizer when plants most need it – this improves plant growth and minimizes fertilizer waste or losses. “While we continue to study and learn how to best manage nutrient programs we know that application of too much nitrogen, especially at the wrong time, can soften fruit,” says Strik. “Anything that could negatively impact fruit storage life is very important.” More than half of the 80 million plus pounds of blueberries produced in Oregon are packed and sold for fresh market.
Strik’s nutrient research continues at Pan American with a goal of giving growers tools they can use to better manage the nutrient programs of the diverse early, mid-, and late-season varieties grown in Oregon. The research involves collecting leaves from the same plants each week and analyzing their nutritional makeup. “We are studying the relationship between leaf nutrient content and plant yield and quality in six varieties,” says Strik. “As a result of this research we should be able to develop leaf nutrient standards that will allow growers to better manage their fertilization programs specifically for each variety.”
“The industry continues to see a real potential for growth of the organic market,” says Strik.
Strik is the lead researcher on the only certified organic research planting of blueberries in the world. The trial is located at the North Willamette Research and Extension Center. “I started doing research on organic blueberries in 2006, because the industry asked me to,” says Strik.
There was a strong potential market for organic fruit, but no research-based information on what production systems would be best for Oregon growers. The Oregon Blueberry Commission funded the establishment of the research trial, using a very large portion of their budget, even though almost all of their assessments were from conventional growers.
“It was an honor to know that the industry had faith that the money would be spent well. Our early findings were critical to us getting a large federal grant to continue the research through planting maturity (this year),” Strik explains.
Since blueberries are a long lived crop, they don’t want to recommend practices if they are not confident that they are sustainable. Every year researchers have shared their findings with more than 125 growers at the annual blueberry field day at NWREC and at grower meetings. The research is starting to have significant impact in the industry in Oregon and outside the region.
“We’ve shown growers that growing blueberry plants in raised beds increases yield by about 20 percent compared to growing on flat ground. Also, we’ve provided growers with guidance on how to best fertilize in organic production systems,” says Strik.
For years, blueberry farmers have mulched blueberry plants with sawdust which serves to retain moisture and add organic matter. Unfortunately, weeds like to grow in the sawdust almost as much as they do in soil. Weeds rob plants of water and nutrients and are costly to manage.
Strik’s research showed that the application of a black, porous, plastic barrier “weed mat” keeps weeds at bay, reduces weed management costs, and helps plants grow well and have a high yield. Now newer fields of blueberries sport the weed mat in organic as well as some conventional fields.
“In this competitive global agricultural industry, we need every advantage we can get,” says Erickson. “The results of the OSU research is available for every grower once it gets published, but if the college‘s hands are tied from budget cuts or other lack of resources, then they can’t do the research the industry needs. Without continuing research and cooperative growers, none of us have anything to gain,” he adds. “For Oregon to maintain its reputation as one of the world leading production areas, growers must continue to cooperate with researchers in any way possible.”