Terry Coffelt, U.S. Arid Land Agricultural Research Center, 21881 N. Cardon Lane, Maricopa, AZ 85239-3004, Dennis Ray, Po Box 210036, University of Arizona, University of Arizona, Dept. of Plant Sciences, Tucson, AZ 85721, and Mike Foster, Texas A&M University, P.O. Box 1549, Pecos, TX 79772.
Guayule (Parthenium argentatum Gray) is a perennial shrub native to the Chihuahuan Desert. Guayule’s use as a natural rubber source dates before 1500 A.D. when Native Americans used its latex to make balls for games. Guayule has been evaluated in the U.S. as a commercial rubber crop during three periods prior to current efforts. The first period was from 1900 to 1930 when automobile and bicycle manufacturers were seeking a rubber source to make tires. Production reached a high of 3,200 ha during the 1920’s. The Great Depression caused all production and research to be terminated about 1929. The second period began during World War II when rubber supplies from Southeast Asia became limited. Commercial production levels reached 13,000 ha during this period. This period ended when the war was over and less expensive rubber from Southeast Asia was again available. The third period began in the 1970’s when oil prices quadrupled and rubber prices increased. This period was devoted primarily to guayule research rather than commercial production. When prices of rubber fell, the funding for guayule research and production stopped. The latest period of commercialization started in the 1980s when research showed that people who developed allergies to Hevea latex were not allergic to guayule latex. An important difference between current and previous attempts at guayule commercialization is that the primary product now includes higher value latex products rather than solid rubber. Commercialization of guayule is closer to reality due to efforts by Yulex Corporation. Yulex has exclusive licensing agreements with USDA-ARS for guayule latex extraction and products in the U. S., built a pilot plant to handle 750 t of biomass/year, planted over 1500 ha of guayule, and are planting another 1500 ha. With these advances, successful commercialization of guayule within the next five years seems very promising.