From Farm to Rubber

Guayule, a humble looking but incredibly resilient desert shrub, could be one key piece of the puzzle as states in the Southwest work to find agricultural solutions to severe drought conditions and water shortages.

The University of Arizona is the lead institution for the Sustainable Bioeconomy for Arid Regions (SBAR) Center, which is funded by a research and education/extension grant through the USDA National Institute of Food and Agriculture (NIFA).

One of SBAR’s primary research areas since its establishment in 2017 has been around the viability of guayule, which is particularly well-suited to central Arizona’s growing conditions and requires about half as much water as alfalfa or cotton and yields natural rubber for tires and co-products like adhesives, hypoallergenic latex, and biofuels like stove pellets.

Bridgestone, an industry partner in SBAR, announced on Aug. 29 that it plans to invest $42 million to establish commercial operations for producing guayule at scale by 2030 while working with central Arizona farmers to target 350 new acres for the crop in the coming year. The company began a guayule initiative in 2012 when it opened a research and processing facility in Mesa, Arizona, later adding a 281-acre farm in Eloy, Arizona.

The UA grows guayule at Maricopa Agricultural Center, the Controlled Environment Agriculture Center (within the Campus Agricultural Center), and the West Campus Agricultural Center. SBAR researchers use the experimental crops to conduct irrigation, weed, disease and pest management field trials, and develop best practices for harvesting.

UA researchers and specialists from CALES and Cooperative Extension have been leaders in SBAR guayule research across all areas. Contributing team members from the division include (José Carvalho de Souza Dias (Plant Sciences-Extension), William “Bill” McCloskey (Plant Sciences-Extension), Peter Ellsworth (Entomology), Blase Evancho (Pinal County Extension), Julia Nielson (Environmental Science), Dennis Ray (Plant Sciences-retired), Diaa El-Shikha (Biosystems Engineering), Trent Teegerstrom (Agricultural Resource Economics), and Peter Waller (Biosystems Engineering).

“As Arizona’s Land Grant University, we’ve worked with the private sector to help create better jobs and generate greater value from our natural resources since 1887,” UArizona Vice President for the Division of Agriculture, Life and Veterinary Sciences, and Cooperative Extension Shane Burgess said. “The bioeconomy is key to our current new economy initiative, and to creating more and better jobs and creating value from much less water. The research around guayule at the Maricopa Agricultural Center exemplifies this. I thank our world-class faculty and staff and our Bridgestone partners for their knowledge tenacity, and vision, that has resulted in this move toward commercialization.”

David Dierig, who leads guayule research at Bridgestone’s farm in Eloy, said SBAR’s work accelerated Bridgestone’s progress toward commercialization.

“SBAR was really a boost to this,” said Dierig, who earned his Ph.D. in genetics at UA in 1987 and wrote his dissertation on guayule. “UA has multiple researchers and disciplines, everything from looking at co-products to herbicides, logistics and transportation, and serving as a location for drip irrigation technology that’s going to save water.”

According to SBAR, guayule is highly efficient not only because of its need for less water—Dierig said guayule can use as little as 2½ acre-feet per year compared to four acre-feet for cotton and six for alfalfa—in that the entire plant can be processed, resulting in almost no waste, herbicides and insecticides are needed only for seeding, and it is easy to harvest in traditional rows.

By expanding its domestic sources of natural rubber, the U.S. would also reduce its dependence on imported products. More than 90 percent of the world’s natural rubber trees are grown in Southeast Asia.

There have been multiple attempts to scale commercialization of guayule in the U.S. over the past century. For example, the U.S. produced 3 million tons of rubber for tires from guayule during World War II, when the country was unable to rely on rubber imports.

Dierig said Bridgestone believes guayule will remain viable for the long-term this time, because of the critical need for agricultural solutions in the face of drought, and a secure domestic source for rubber.

“There’s been a longtime effort to get this established commercially,” he said. “But the thing that really makes it important this time is that there’s an interest and pull from industry and the public. Before, it was always a pull from the government.”