The Guayule shrub in the southwestern U.S. could supply rubber, insect repellent and glue, and could help in the fight against cancer.
The Scientific American says researchers have been investigating guayule (Parthenium argentatum) for decades as a potential commercial source of natural rubber.
The market is currently dominated by rubber sourced from Hevea brasiliensis trees in Southeast Asia, and it’s hard for guayule in the U.S. to compete with those large operations, which have lower labor costs, while farmers in the Southwest tend to favor more lucrative crops, such as alfalfa and cotton.
But fungal infestations of monocultured Hevea trees have caused steep drops in global natural rubber supplies in recent years, and the Southwest’s drought has reduced the water available to farmers, making it harder to grow alfalfa, cotton and other crops.
Guayule, on the other hand, is drought-tolerant, and it can be grown and harvested for several years without tilling the soil, with the undisturbed soil storing carbon in the ground and preventing erosion.
Tire manufacturer Bridgestone has operated a demonstration-scale processing facility in central Arizona for the past decade in an effort to show that guayule can eventually be harvested for natural rubber at a commercial scale.
In late August the company announced it would commercialize guayule rubber production by 2030.
Though two thirds of the world’s rubber is now made synthetically from petroleum, rubber produced from natural sources is indispensable for some purposes.
Airplane tires, for example, are made from natural rubber, which is superior to synthetics for handling impacts such as landing on the runway.
Other researchers think the real moneymaker could be guayule resin.
The sticky substance is made up of many organic compounds, including essential oils that could be used as fragrances and other molecules called guayulins and argentatins that are unique to guayule.
The researchers say the resin compounds hold promise for a number of potentially lucrative uses.
Scientists at the University of Arizona found the resin could be used for plant-based adhesives, potentially replacing some formaldehyde-containing products such as wood glue.
A recent study also found that argentatin-derived compounds were toxic toward three types of cancer cells, opening the possibility for their use in drug investigation.