Tumbleweeds may be an icon of the Old West, but for modern westerners they're nothing but a nuisance. When they grow—as big, green spindly bushes—they take over farming and grazing land. When they dry up in the fall they become a traveling fire hazard: “rolling balls of kindling,” says Louis Sahagun for the Los Angeles Times. Now, researchers with the U.S. Agricultural Research Service have a plan to eradicate the tumbleweed by unleashing an imported fungus, says Popular Science.
Despite their iconic status, tumbleweeds are not native to America. Instead, as Smart News wrote previously, they were brought over from Asia in the late 1800s. After decades of searching, says Francie Diep for Popular Science, researchers with the U.S. agricultural service think the best bet to take out America's tumbleweed infestation is to use the plant's natural foes. The team are awaiting permission to release two fungi imported from Russia into the wild.
Before they sought permission, says Diep, the researchers tested whether the fungi would be able to infect native species. Based on their work, she says, the pathogen seems promising:
The team checked 89 species' vulnerability to C. salsolae, plus 64 species' vulnerability to U. salsolae. Only a few species were vulnerable to infection at all. Those that were didn't seem to suffer in overall health from the infection. One helpful fact: Plant diseases tend to infect closely related species and there are no plants native to the U.S. that share tumbleweeds' genus, Salsola.
Tumbleweeds are generally a background problem, but they have a tendency to flare up when it's particularly dry, says the Los Angeles Times. In California right now, the ongoing drought has triggered a boom in tumbleweed populations.