In 2004, the History Channel broadcast a Modern Marvels Special on Natural Rubber. My favorite quote from that special is “Our four most important natural resources are air, water, petroleum, and rubber.” (I would have argued for soil to be part of the list.) Nonetheless, while most people guess the first two, some also guess petroleum; almost no one imagines that rubber is fourth on the list.
I recently found out that many Ohioans think that black rubber, like what we see in tires, seals and gaskets and hoses, is synthetic and derived from petroleum. In fact, this is far from true — natural rubber looks black when it is reinforced with carbon black — Natural rubber is used to make about 50,000 different products. The rubber component of a passenger car tire may be 50% natural and 50% synthetic, but the higher the performance required the greater the proportion of natural rubber. Airplanes land on 100% natural rubber tires — if synthetic polymers were added these tires would not take the stress of landing and would explode. Truck tires are 95% to 100% natural rubber. All natural rubber has been harvested by tapping tropical rubber trees and the United States has imported all we require. This is an enormous amount each year of about 1.5 million metric tons or 3,306,000,000 lbs. However, we now face a significant supply problem. As Southeast Asia, China and Brazil expand and develop their economies, they need more and more rubber. The increasing demand is greater than all of our imports so where shall we get the rubber we need?
To address this critical supply issue, OARDC scientists are developing an annual rubber crop for Ohio farmers as quickly as we can. This crop plant, a cousin of our common dandelion, is being developed by improving plants collected from the wild from Kazakhstan by USDA in 2008. The species name is Taraxacum kok-saghyz, erroneously called the Russian dandelion when it was grown at sites all over the United States during World War II. Our new selections are named Buckeye Gold — gold for the flowers and gold for the money we hope our farmers and rubber manufacturers will make. The quality of the rubber is almost identical to the rubber tree rubber. It is a root crop, but the rosettes can be used for feed or biofuels. Since it can be grown as an annual, we think that it will become part of our normal crop rotation. In 2013, we planted 8 acres at three OARDC research stations and on a local commercial farm, the largest North American planting in 70 years. We also began planting box studies (figure 3) to understand the yield potential of this new industrial crop. Since then we have used rapid phenotyping methods to select large plants with triple the rubber content, which are being interbred this spring. Germains Seed Technology of California has primed and pelletized improved seed for us and this has been planted on several acres. Its biggest challenge is weed control — we need to kill the common dandelions without killing the rubber dandelions.
Our results indicate that Ohio farmers should quite soon be able to grow this new crop on a large enough scale (several million acres) to make the United States self-sustainable for natural rubber production, and then expand to allow this country to become a rubber exporting country!
Many new rubber extraction refineries will be needed, creating many new jobs across the agribusiness continuum. The first of the rubber biorefineries, on a pilot scale, became operational in Wooster, Ohio, in December 2012, thanks to a Third Frontier grant from the Ohio Department of Development. OARDC scientists are actively working to make this crop and process commercially viable, and work closely with industrial (Cooper, Bridgestone and Ford) and academic (Oregon State University and the University of Guelph) consortium partners in the Program of Excellence in Natural Rubber Alternatives. For more information, contact Dr. Cornish and check out her website: http://cornishlab.cfaes.ohio-state.edu.