Banana variety risks wipeout from deadly fungus wilt

http://www.theguardian.com/global-development/2015/jan/21/banana-deadly-fungus-wilt-fao-cavendish-fusarium

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A global plan to fight Fusarium wilt, a fungus spreading from Asia to Africa and the Middle East, is needed to prevent the world’s most popular banana variety – the Cavendish – from disappearing.

The UN’s Food and Agricultural Organisation (FAO) and 30 other organisations have estimated that a strategic global plan to contain the disease could cost $47m to implement.

The destructive fungus, Fusarium oxysporum f.sp. cubense Tropical Race 4, or TR4, has afflicted Asia for more than 20 years, affecting China, Indonesia, Malaysia and Taiwan. It also occurs in northern Australia.

Its appearance in Mozambique in early 2013 raised the alarm of cross-continent spread, and sparked moves to devise the global plan, the main goals of which were discussed last month during a meeting in Rome where the FAO is based.

A major reason for concern is that most banana plantations in Asia, Africa and South and Central America are planted with a single variety, the Cavendish, which is susceptible to the fungus.

Perennial, high yielding and with long “green life” which makes it easy to ship, the Cavendish has dominated banana production since a formerly popular variety, Gros Michel, was wiped out by Fusarium Race 1 fungus in the 1950s.

Farmers use hundreds of varieties but if the fungus kills many of them we will face a serious food security problem

Altus Viljoen, a plant pathologist at Stellenbosch University in South Africa, says the $47m figure is appropriate as “the task ahead of us is immense”.

Under the plan, part of the funds will be used for rapid reactionassistance to countries facing new outbreaks.

“There are no regulations in place at the moment, no common phytosanitary practices and quarantine systems. We have to build all of this together,” said Viljoen.

Appropriate risk assessment is also needed, not only on Cavendish plantations but for other varieties that may be susceptible to Fusarium wilt.

The FAO has been working since early 2013 in Africa in collaboration with Stellenbosch University and the Mozambique government. But now there is an urgent need to step up efforts, according to Fazil Dusunceli, FAO agricultural officer and a central figure in the creation of the plan.

While resources have not yet been allocated to the plan, the estimated budget covers measures to prevent the spread of the disease into non-infected regions.

“We need appropriate policies and strategies to foster awareness at all levels,” Dusunceli said. “It means working with government officials and banana producers to reduce the risks of contamination through movement of people, vehicles or exchange of materials.”

Training, surveillance, early-detection systems, and international coordination and exchange of knowledge are also necessary.

“We raised an alarm when [TR4] was detected in the Philippines in 2005,” said Agustin Molina, senior scientist with Bioversity International in Asia. “Our awareness campaign has probably reduced the spread of contamination. But we are glad to see that now, with the occurrence of the disease in Mozambique, the alert has gone global.”

Its long-term experience of TR4 makes Asia the biggest player in the plan, particularly in research to find resistant varieties. The proposed funding figure includes research and development on resistant varieties.

Many wild banana and plantain varieties are not edible, but they hold untapped genetic material that, with increased investment in research, could be used to make banana production more resilient to disease, the FAO says.

“The Taiwan Banana Research Institute has identified some TR4-resistant Cavendish bananas,” Molina said. They are undergoing field tests.

Molina said the Asian experience shows there is hope for small-scale farmers, since “the diversity of varieties and the mix of plants grown together by small farmers lowers the risks of total loss”.

But the fungus still poses a threat to food security. “In Africa, bananas are one of the major staple foods. Only 15% of the production goes for the export market, the rest is consumed locally,” said Viljoen.

“In many countries there is a yearly consumption of 300kg of banana per person. Farmers use hundreds of different varieties but if the fungus kills many of them we will face a serious food security problem,” he said, referring to the possible spread to other varieties.