The pathogenic fungus Fusarium wilt tropical race 4 (TR4), already widespread on several other continents, has been found for the first time infecting banana plants in Latin America, researchers confirmed earlier this month (August 8). Fungicides are ineffective against the disease, and observers have long feared its incursion into the world’s top banana-producing region. Colombia has declared a national emergency to try to contain its spread.
“These epidemics develop slowly, so the [spread of TR4] will take some time,” Randy Ploetz, a plant pathologist at the University of Florida in Homestead, tells Nature. “But eventually, it will not be possible to produce Cavendish [banana variety] for international trade.”
As NPR reports, TR4 was first detected in Taiwan in the 1990s. From there it spread to other parts of Asia, and eventually Australia and Mozambique. Last month, Fernando Alexander García-Bastidas, a banana researcher at the Dutch company Keygene, received photos from Colombia of banana trees showing signs of TR4 infection; he flew to the country and carried out tests confirming the fungus’s presence.
Many varieties of bananas and plantains, including the Cavendish common in grocery stores, are susceptible to TR4 infection. García-Bastidas is among the researchers who’ve tried to develop resistant varieties that could be cultivated commercially. In a previous study, “80% of the [varieties] that I tested were susceptible to TR4,” he tells NPR. “But there is a little bit of hope with the other ones that were not susceptible.”