By Emilio Godoy
The deserts of northern Mexico are home to various plant species that have been largely ignored, despite the considerable social, economic and environmental contributions they could make.
Guayule (Parthenium argentatum Gray) is a shrub that grows along the border between Mexico and the United States. It is a natural source of latex that can be used as an alternative to the latex obtained from rubber (Hevea) trees, with the added advantage that it does not cause the allergic reactions provoked in some people by Hevea-derived rubber. It is therefore an excellent source of latex for the manufacture of medical supplies like gloves and catheters.
Jojoba (Simmonsdia chinensis) is another shrub that is native to the Sonora Desert on the Mexican-U.S. border, as well as the Mojave Desert in the southern United States. It is the only plant that produces liquid wax ester (commonly referred to as jojoba oil) which can be used in the production of everything from cosmetics and lubricants to plastics and biodiesel.
The two shrubs have very different histories. Jojoba production has enjoyed relative prosperity in some parts of the world, while guayule production was largely shelved following a brief period of commercial success in the first half of the 20th century.
“After intensive efforts in the 1970s and 1980s to promote large-scale marketing (in Mexico), guayule was pushed aside by the petroleum boom. It currently isn’t exploited. It holds considerable potential, but long-term strategic resources are needed to take advantage of it,” Enrique Campos, a researcher at the Center for Research and Assistance in Technology and Design of the State of Jalisco, in western Mexico, told Tierramérica.
In the 1980s, Campos headed up the design and construction of a plant for the extraction and processing of guayule latex at the Research Center for Applied Chemistry (CIQA), located in the northeastern Mexican city of Saltillo. But the initiative never got off the ground.
The shrub first came to worldwide attention in 1911, when Francis Ernest Lloyd, a professor of plant physiology at the Alabama Polytechnic Institute in the southern United States, published the book “Guayule (Parthenium argentatum Gray): A Rubber Plant of the Chihuahuan Desert” after exploring the region for the Continental-Mexican Rubber Company and the Intercontinental Rubber Company.
According to the Mexican National Commission for the Knowledge and Use of Biodiversity (CONABIO), its benefits also include its capacity to conserve soils, prevent erosion and improve soil fertility.
As for jojoba, CONABIO stresses its potential for the restoration of degraded lands. The Digital Library of Mexican Traditional Medicine reports that boiled jojoba seeds and flowers can be used as a natural cough remedy, while crushing the plant’s nuts into a paste and applying it to the scalp can prevent hair loss.
Both plants were used by the region’s indigenous peoples in pre-Hispanic times. The Chichimeca people of northern Mexico used guayule latex to make rubber balls for a sport similar to handball, while the Seri of the Sonora Desert use jojoba seeds in ancestral rituals and to heal cuts and wounds.
In a 2003 study, “Guayule: Relación entre producción de biomasa, síntesis de hule y condiciones climáticas” (Guayule: Relationship Between Biomass Production, Rubber Synthesis and Climatic Conditions), researchers Diana Jasso and Raúl Rodríguez from the Antonio Narro Agrarian Autonomous University and José Angulo from CIQA highlighted the importance of the link between temperature and rainfall in the synthesis of rubber in the guayule plant.
“Low rainfall levels improved rubber accumulation, whereas high rain levels did not. However, high precipitation also improved biomass production,” the study found.
The world’s largest producers of jojoba, whose oil can be used in place of whale oil, are Argentina, Israel, the United States, Australia, Peru and Mexico.
CONABIO reports that a number of jojoba production projects in Mexico failed because of a duplication of functions among the entities involved and the resulting confusion among producers.
In any case, before jojoba production can be effectively promoted, “markets will have to be developed so that the price of the seeds remains at a relatively stable level that can ensure a financial return for producers,” Robert Roth, director of the Maricopa Agricultural Center at the University of Arizona, told Tierramérica.
This research center has conducted research on jojoba and guayule, among other plant species. In fact, both plants have been studied in much greater depth in the southern United States, although this has not yet led to large-scale production. There is only one jojoba plantation currently operating, after hundreds of hectares were planted in response to the oil crisis in 1973.
Given this situation, Campos believes that “many resources in this region need to be viewed in the light of new scientific advances, in terms of genetics, agronomics and industrial processes. Preliminary assessments need to be carried out, and in cases that demonstrate potential, a way should be found to initiate strategic projects.”
In Roth’s opinion, “what needs to be developed first is a market where the oil can be sold. This market has to be big enough to ensure that that the production of jojoba doesn’t exceed the demand.”