https://asia.nikkei.com/Business/Ag...1&pub_date=20220808190000&seq_num=29&si=44594
Banana growers fight renewed extinction risk as lethal fungus spreads
Resurgence of Panama disease threatens one of world's most valuable crops
Bananas are displayed at a shop in Halle, Belgium. Eaten across the world, the fruit is grown in the tropics, from Southeast Asia to Latin America. © Reuters
KOJI KATO, Nikkei science editorAugust 8, 2022 00:27 JST
TOKYO -- Decades after decimating banana plants worldwide, Panama disease once again threatens to wipe out the crop key to economies across Asia, Latin America and beyond.
Vietnam will lose up to 71% of its banana-producing land in 25 years to a type of fungus called Fusarium, warned a scientific paper published in February by researchers from institutions including Vietnam's Plant Resources Center and Belgium's Meise Botanic Garden. Fusarium enters the banana plants through its roots and destroys its veins, causing the plant to wilt. The spores can contaminate soil for decades.
Bananas are "among the most important food crops worldwide," said Steven Janssens, one of the authors. And if Fusarium continues to spread, he says that "the impact on humanity could be quite dramatic."
A separate study cited in the paper predicted a similar loss of banana-producing land in China and the Philippines.
The dangers of Fusarium came under the spotlight in the 1950s, when the fungus devastated banana plants in and around Panama. Dubbed Panama disease, the epidemic subsided only after inflicting billions of dollars in damage to growers and nearly wiping out production of the Gros Michel cultivar.
Half of the bananas grown in the world today are the Cavendish, which has been relatively resistant to Fusarium wilt. But a new strain that emerged in the 1990s is now attacking Cavendish bananas in Malaysia and elsewhere in Southeast Asia.
The strain, called tropical race 4 or TR4, was also found in Colombia in 2019 and Peru in 2021, sparking concerns that the world's entire banana crop may be at risk of extinction.
The modern banana is descended from a seedless variety that began to be cultivated in Southeast Asia around 5,000 B.C. or earlier. Growers propagate plants through cuttings that are genetically identical to the "parent" plant, heightening the risk of populations being wiped out by a pathogen like TR4. The lack of seeds makes it trickier to breed new varieties with better disease resistance.
More than 100 million metric tons of bananas are produced worldwide annually, and there have been no signs of a significant decline.
"I don't think bananas will go extinct," said Tsutomu Arie, a professor at the Tokyo University of Agriculture and Technology (TUAT) who specializes in plant pathology.
It is hard to gauge just how endangered the world's banana population is, but TR4 is a source of much anxiety in the industry.
The fungal strain has been reported in roughly 20 countries, hitching rides on infected plants or on people via contaminated soil or planting material. The only sure way to curb its spread is by quarantine.
According to the United Nations' Food and Agriculture Organization, India is the world's top banana producer at 31.5 million metric tons, followed by China with 11.51 million metric tons, then Indonesia, Brazil, Ecuador and the Philippines. Since some of these countries grow much of their crop for domestic consumption, most exports come from Central and South America.
The economic impact of the banana market has been estimated in the tens of billions of dollars, and the loss of even a portion of that would be felt by the global economy.
Workers unload bananas from trucks at a market in Kolkata. India is the world's top producer of the fruit, according to the U.N. Food and Agriculture Organization. © Reuters
Vaccination is among the strategies that Arie and others are working on to deal with TR4. Inoculating plants with a harmless variety of Fusarium fungus would boost resistance to the more dangerous type or keep it away from their roots.
Starting in fiscal 2023, a Japanese team led by TUAT will work with partners including La Molina National Agrarian University in Peru on countermeasures including diagnosis and soil management.
James Dale, a professor at Queensland University of Technology in Australia, said his team has adopted gene editing to develop banana trees that are hardy against TR4.
With the introduction of genetically modified bananas strictly regulated, the variety is not expected to be grown for commercial purposes in Australia by the end of 2024.
Yet this represents a significant advance. "It contains a resistance gene that we transferred from a wild banana that is immune to TR4," said Dale.
Some scientists blame the fungal disease's spread on decades of cultivating and producing bananas selected only to satisfy taste buds. Diversity is thought to shield against plant disease epidemics.
Hundreds of varieties of bananas grow within the "banana belt" found up to 30 degrees north and south of the equator. Bananas are not only a food, but also a key source of revenue. Nearly 500 million people are estimated to depend on bananas as a staple food.
Banana growers fight renewed extinction risk as lethal fungus spreads
Resurgence of Panama disease threatens one of world's most valuable crops
Bananas are displayed at a shop in Halle, Belgium. Eaten across the world, the fruit is grown in the tropics, from Southeast Asia to Latin America. © Reuters
KOJI KATO, Nikkei science editorAugust 8, 2022 00:27 JST
TOKYO -- Decades after decimating banana plants worldwide, Panama disease once again threatens to wipe out the crop key to economies across Asia, Latin America and beyond.
Vietnam will lose up to 71% of its banana-producing land in 25 years to a type of fungus called Fusarium, warned a scientific paper published in February by researchers from institutions including Vietnam's Plant Resources Center and Belgium's Meise Botanic Garden. Fusarium enters the banana plants through its roots and destroys its veins, causing the plant to wilt. The spores can contaminate soil for decades.
Bananas are "among the most important food crops worldwide," said Steven Janssens, one of the authors. And if Fusarium continues to spread, he says that "the impact on humanity could be quite dramatic."
A separate study cited in the paper predicted a similar loss of banana-producing land in China and the Philippines.
The dangers of Fusarium came under the spotlight in the 1950s, when the fungus devastated banana plants in and around Panama. Dubbed Panama disease, the epidemic subsided only after inflicting billions of dollars in damage to growers and nearly wiping out production of the Gros Michel cultivar.
Half of the bananas grown in the world today are the Cavendish, which has been relatively resistant to Fusarium wilt. But a new strain that emerged in the 1990s is now attacking Cavendish bananas in Malaysia and elsewhere in Southeast Asia.
The strain, called tropical race 4 or TR4, was also found in Colombia in 2019 and Peru in 2021, sparking concerns that the world's entire banana crop may be at risk of extinction.
The modern banana is descended from a seedless variety that began to be cultivated in Southeast Asia around 5,000 B.C. or earlier. Growers propagate plants through cuttings that are genetically identical to the "parent" plant, heightening the risk of populations being wiped out by a pathogen like TR4. The lack of seeds makes it trickier to breed new varieties with better disease resistance.
More than 100 million metric tons of bananas are produced worldwide annually, and there have been no signs of a significant decline.
"I don't think bananas will go extinct," said Tsutomu Arie, a professor at the Tokyo University of Agriculture and Technology (TUAT) who specializes in plant pathology.
It is hard to gauge just how endangered the world's banana population is, but TR4 is a source of much anxiety in the industry.
The fungal strain has been reported in roughly 20 countries, hitching rides on infected plants or on people via contaminated soil or planting material. The only sure way to curb its spread is by quarantine.
According to the United Nations' Food and Agriculture Organization, India is the world's top banana producer at 31.5 million metric tons, followed by China with 11.51 million metric tons, then Indonesia, Brazil, Ecuador and the Philippines. Since some of these countries grow much of their crop for domestic consumption, most exports come from Central and South America.
The economic impact of the banana market has been estimated in the tens of billions of dollars, and the loss of even a portion of that would be felt by the global economy.
Workers unload bananas from trucks at a market in Kolkata. India is the world's top producer of the fruit, according to the U.N. Food and Agriculture Organization. © Reuters
Vaccination is among the strategies that Arie and others are working on to deal with TR4. Inoculating plants with a harmless variety of Fusarium fungus would boost resistance to the more dangerous type or keep it away from their roots.
Starting in fiscal 2023, a Japanese team led by TUAT will work with partners including La Molina National Agrarian University in Peru on countermeasures including diagnosis and soil management.
James Dale, a professor at Queensland University of Technology in Australia, said his team has adopted gene editing to develop banana trees that are hardy against TR4.
With the introduction of genetically modified bananas strictly regulated, the variety is not expected to be grown for commercial purposes in Australia by the end of 2024.
Yet this represents a significant advance. "It contains a resistance gene that we transferred from a wild banana that is immune to TR4," said Dale.
Some scientists blame the fungal disease's spread on decades of cultivating and producing bananas selected only to satisfy taste buds. Diversity is thought to shield against plant disease epidemics.
Hundreds of varieties of bananas grow within the "banana belt" found up to 30 degrees north and south of the equator. Bananas are not only a food, but also a key source of revenue. Nearly 500 million people are estimated to depend on bananas as a staple food.
