Some of the leading research being done on stevia, a plant that is 200-300 times sweeter than sugar, is taking place in the Treasure Valley area of Idaho and Eastern Oregon.
Once that happens, the plant could be an attractive option for the region’s farmers.
But the plant likely won’t be grown commercially here until researchers learn how to reliably produce the small shrub from seed.
Stevia is used as a natural sweetener in drinks and food.
Unlike potatoes, corn and other crops that farmers have bred for hundreds of years, stevia has only been researched for about 50 years, said Cheryl Parris, research and development manager at S&W Seed Co.
Because of that, there is currently too much genetic diversity in stevia to grow it from seed, so it’s being grown from clones, or rooted cuttings, that are produced in a greenhouse and then transplanted into the field.
The labor and expense involved in growing stevia that way at 40,000 plants an acre makes it too expensive to be an attractive alternative to commercial farmers in the U.S., Parris said.
The company’s stevia research is centered in Nampa. Parris is trying to develop a reliable seed line that farmers can plant.
She said this is an ideal region for growing stevia. The company has received a lot of inquiries from farmers interested in growing stevia seed.
“There is a lot of variability in the plants because there is so much that hasn’t been bred out yet,” she said. “It will become more ideal as we develop a seed line. It’s still really an emerging market in the United States because of the cost at this point.”
The wide genetic diversity in stevia means the progeny is usually not as good as the parents, said Clint Shock, director of Oregon State University’s research station in Ontario.
“How to efficiently propagate stevia by seed hasn’t been solved,” said Shock, who has researched the plant for more than a decade. “In order for it to be competitive in the U.S., you need to be able to cross reliably and efficiently from seed. That is the Achilles heel of growing stevia in the United States.”
Most of the world’s stevia is grown in nations with much lower labor costs, Shock said.
“The competitive advantage now is for places that have super cheap labor,” he said.
Parris and Shock are also trying to breed out the sometimes bitter aftertaste associated with stevia.
“We’re trying to develop a plant that tastes better, doesn’t have a bitter aftertaste and can be used more as an additive to food products,” Parris said.