WOOSTER, Ohio—For Katrina Cornish, transforming Taraxacum kok-saghyz, commonly known as the Russian dandelion, into a viable and profitable source of natural rubber is the ultimate goal.
Now, with the introduction of direct seeding of dandelion fields, that goal has become closer, according to Cornish, endowed chair and Ohio scholar in bio-emergent materials at Ohio State University's Ohio Agricultural Research and Development Center in Wooster.
This year marked the first year that most of the OARDC's dandelion crop was planted by direct seeding instead of the much more labor-intensive and costly transplantation, she said.
“We put in about five acres with direct seeding and two with transplantation,” she said.
Germains Seed Technology Inc., a global agricultural technology company with U.S. operations in Gilroy, Calif., worked with Cornish and the OARDC to develop pelletized seeds for “Buckeye Gold,” the strain of dandelion developed in Wooster.
Germains developed the world's first pelletized seeds, for sugar beets, in 1945, according to Dale Krolikowski, head of research and operations at Gilroy.
“Traditionally, the creation of a pellet around a seed improves the shape and size of the seed for precise mechanized planting,” he said. “With mechanized planting, the pelletized seed can be sown at controlled depths in the soil with proper spacing between plants.”
Germains specially formulated the pelletizing material for Buckeye Gold to enhance the performance of the seedlings, Krolikowski said. The company also has worked with the OARDC to improve the speed and uniformity of seedling emergence, using a technique called priming, he said.
“Priming (Buckeye Gold) seed has been a special technical challenge, and if successful will provide OSU with additional benefits to assist in its goals to produce (dandelion) crops on a commercially viable scale,” he said.
One thing pelletizing of dandelion seeds has done already, according to Cornish, is to lower the cost of planting them by about 95 percent.
“We worked out the cost of planting dandelions through transplanting, and it came out to $5,917 per acre,” she said. “We haven't yet worked out the cost of direct seeding, but it's a couple of hundred dollars per acre, tops.”
A cousin to the common lawn dandelion, Taraxacum kok-saghyzis native to the Russian steppes. Although Buckeye Gold is a descendant of Taraxacum brought to the U.S. in 2008 by the U.S. Department of Agriculture, Cornish said, all of the breeding and development work on this variety of dandelion was done at the OARDC.
“One thing I can definitely tell you is that it's not Russian,” she said.
Since it began its research into Buckeye Gold, the OARDC has planted about 20 acres, according to Cornish. If lined up end to end, the dandelions planted so far would stretch about 61 miles, she said.
Though some Buckeye Gold plants are perennial or biennial, the majority are annual, she said. Generally, she said, about 500,000 to 1 million dandelions are planted per acre.
Because of the exceptionally cold winter last year, only about 50 percent of the stored plants survived, Cornish said. That made the spring harvest smaller than the previous fall harvest, she said—about 1,073 pounds of rubber per acre in the spring, compared with approximately 1,500 pounds per acre in the fall.
Cornish has a particularly strong background in alternative rubber sources. In the 1990s, she led the research team at the U.S. Department of Agriculture that created and patented a process of extracting hypoallergenic latex from guayule, the desert shrub that is Taraxacum's main rival. Later, in the 2000s, she was senior vice president of research and development at Yulex Corp., the company that won the USDA's license to commercialize the patented guayule latex process. (Yulex remains one of the leading guayule development companies.)
Comparing guayule and dandelion rubber, Cornish said dandelion rubber is closer to Hevea rubber than guayule rubber in its structure and properties, and also in its proteins. Dandelion rubber tends to be solid with good manufacturing properties, she said, whereas guayule rubber tends to be “very stretchy, very soft, very strong.”
Besides direct seeding, OARDC researchers are concentrating on weed control, as well as on finding and breeding large dandelions with high rubber content, Cornish said. She and her colleagues are using infrared spectroscopy to identify plants that will yield the most rubber, she said.
Through a Third Frontier grant from the Ohio Department of Development, the OARDC established a pilot rubber biorefinery in Wooster in December 2012, according to Cornish. The OARDC has planted dandelion crops on two commercial farms this year, and one in particular is interested in pursuing the commercialization of dandelions, she said.
While she didn't give a timetable for growing the first commercial crop of Buckeye Gold, Cornish said, “I think we're getting pretty close.”