Native Crops: Commercial Uses for Prickly Pear and Guayule
The desert offers abundance if you just know where to look. Cactus, mesquite, creosote, and other useful plant life thrives, untended, in the dry, rocky soil and scorching summers of Arizona’s deserts. American Indian tribes have depended on native plants for thousands of years, even before they cultivated corn and cotton.
Some farmers and businesses are turning these native, low-maintenance plants into income. The scale of production varies, but exciting uses for indigenous fauna open the door to a whole new array of agricultural possibilities that do not reduce the water table. Two are listed below.
Used for centuries by Indian tribes of the southwest and Mexico, guayule (pronounced why-YOO-lay) is one of the most promising new crops in Arizona. This unassuming low bush that grows wild throughout the Chihuahuan desert that crosses southeastern Arizona and northern Mexico is used to make one of the world’s most used commodities: rubber.
Though over 2,000 varieties of rubber-producing plants grow worldwide, the Brazilian rubber tree (Hevea brasilensis), heavily cultivated in the tropics of Southeast Asia, is the only commercial source of natural rubber and latex products—besides guayule. The low water, low maintenance guayule plant offers a domestic source of rubber that is lower in protein and thus more hypoallergenic than Hevea products. Native to the desert southwest, it requires significantly less water than other types of rubber plants. Why then, hasn’t guayule been cultivated before? Turns out, it has.
Guayule was harvested around the turn of the century by rubber producers on the U.S.-Mexico border. It enjoyed a second, brief boom during World War II when rubber imports from Southeast Asia were cut off. But its popularity skyrocketed in the 1980s when the widespread use of disposable rubber gloves in the medical industry revealed a fairly common latex allergy. The lower protein content of guayule decreases skin reactions. Today, medical companies such as Yulex are exploring its use in a wide scope of medical products, as well as transportation, defense, and other specialized industries.
The largest challenge to widespread cultivation seems to come with adjusting this wild plant to cultivation. Establishing a crop is difficult. Moreover, rubber is made from the thick, woody branches of the shrub, so plants with sturdy branches are favored over larger plants with many leaves and flowers. However, once a crop is established, the rubber-producing bark may be harvested without killing the root, so annual replanting is not necessary.
Despite the challenges that come with domesticating a wild crop, this native plant’s commercial potential seems limitless. Moreover, the going price for medical-grade rubber is several dollars per pound over the price of rubber used for other industries, and a worldwide rubber shortage is predicted in the next few years. In addition to creating high quality, hypoallergenic rubber for specialized use, a recent USDA study indicated that the plant has anti-fungal properties and produces a natural termite pesticide. It is also a source of resin and wax.
Though the market is still relatively small, farmers are beginning to cultivate guayule. The Red Rock Agriculture Experiment Center is experimenting with growing methods for this as well as with algae, sweet sorghum, and other alternative crops. Cotton farmers have a special incentive to experiment. Guayule can be grown and harvested using the same equipment as cotton, and requires about two-thirds less water to grow. As guayule companies expand, there is little doubt that this little known word will get more recognition. In fact, plans to open a biorefinery here in Arizona are in discussion.