MELBOURNE – Six decades after a banana-killing fungus all but wiped out plantations across Latin America, a new strain threatens to destroy global harvests.
A type of fusarium wilt appeared this year in Australia’s main banana-growing state and also has spread to Asia and Africa.
While the fungus has been around since the 1990s and has not affected the top banana exporter Ecuador, Fresh Del Monte Produce called it a potential “big nightmare.”
The United Nations says the disease threatens supply, and Latin American growers have begun to take steps to reduce their risks.
The industry survived the demise of the top-selling Gros Michel banana in the 1950s by switching to a different variety, called the Cavendish. But this time, there’s no ready substitute.
Americans are the biggest buyers, and the export market for bananas is valued at more than $7 billion.
“We don’t have anything that can replace the Cavendish,” said Gert Kema, a plant research leader at Wageningen University in the Netherlands, who studies banana diseases.
While the U.S. and European Union are the top importers, Ecuador and the Philippines are the top shippers.
Over the past two decades, a new strain of fusarium wilt – called Panama disease Tropical Race 4 – emerged to threaten the Cavendish, including in the Philippines and China and in parts of Africa. This year, it was found in Queensland state, where more than 90 percent of Australia’s $467 million crop is grown.
TR4 enters the plant’s roots and spreads, invading vascular tissue. The first symptom is irregular yellowing of older leaves, which later turn brown and dry out. The disease poses no threat to humans.
Growers from across Latin America met in March to create a regional defense effort and will gather again in September or October, said Eduardo Ledesma, director of the Banana Exporters’ Association in Ecuador. No specific regional measures are in place, though Ecuador growers have asked the government to fumigate all containers, he said.
“If we carry out these controls at a regional level, then it will be very difficult for it to spread,” Ledesma said from Guayaquil, Ecuador. “Not impossible, because nothing is impossible in life, but very difficult.”
Researchers like Wageningen’s Kema aren’t so sure. They say the disease will continue to spread, despite efforts to contain it, as long as susceptible varieties are being grown.
While there are thousands of varieties of bananas, those that are commercially produced for export almost all Cavendish, which allows growers, distributors and retailers to ensure uniform quality in appearance and taste for consumers.