As Temperatures Rise, Banana Disease Poses ‘Particularly High Risk’ to Global Supplies

a soil-borne fungal disease affecting the world's most popular tropical fruit- traces its origins to Taiwan in the 1970s. According to the Food and Agriculture Organisation of the United Nations (FAO), the Tropical Race 4 (TR4) strain was detected in Australia, China, Indonesia and Malaysia in the 1990s. By 2013, the strain had spread to Africa and within six years to Latin America - home to two-thirds of the world's banana trade of more than 19 million tonnes a year. LATEST STRAIN CONFIRMED IN MOST SOUTHEAST ASIAN COUNTRIES By 2020, the TR4 Global Network says, the strain had been confirmed in 22 countries - mostly in South and Southeast Asia including Laos, Myanmar, the Philippines, Thailand and Vietnam. Although the network does not mention Cambodia, local growers have been struggling with the disease 'for decades,' the secretariat of the International Plant Protection Convention (IPPC) said last year. The Global Network - an initiative of the World Banana Forum hosted by the FAO Secretariat in Rome - says TR4 is 'one of the most aggressive and destructive fungi in the history of agriculture and the world's greatest threat to banana production.' Its continued spread 'will be devastating for the communities who rely on bananas for their livelihoods, but also sad for those who simply enjoy eating them.' BANANA GROWERS NOW FACE ADDITIONAL THREAT OF CLIMATE CHANGE According to the FAO and the Organisation of Economic Cooperation and Development (OECD), growing bananas and other tropical fruits is "increasingly difficult and costly' amid extreme weather related to climate change. 'In the face of rising temperatures, more rapid and severe spreads of plant pests and diseases such as Banana Fusarium Wilt are being observed,' says the OECD-FAO Agricultural Outlook for 2024 to 2033 released last week. The TR4 strain is 'currently expanding' and 'poses particularly high risks to global banana supplies as it can affect a much broader range of banana and plantain cultivars than other strains.' NO EFFECTIVE FUNG ICIDE AVAILABLE Despite recent breakthroughs in the engineering of resistant varieties, no effective fungicide or other eradication method is currently available,' the outlook says. Further spread of the TR4 strain would involve 'considerable loss of income and employment in the banana sector in the affected countries, as well as significantly higher consumer costs in importing countries,' it warns. The Global Network notes that bananas are 'critical' to food security and the livelihoods of around 400 million people worldwide. Effective resistance to the disease is "urgently needed to avoid losses in a diverse array of sectors and communities,' it says. "Research to breed TR4-tolerant or resistant varieties is being carried out by several institutions, but this takes time.' 'Currently, the most effective approach to combat TR4 is to prevent its spread to clean areas and to contain it as soon as it is detected." PREVENTIVE MEASURES IN CAMBODIA In Cambodia, the IPPC secretariat launched a US$2 million p roject with China on phytosanitary capacity development in 2019 - including measures such as integrated pest management (IPM) to combat TR4 and an earlier strain of the disease. In addition to phytosanitary measures, Cambodia also received training in IPM technologies to combat the disease and field demonstrations of new Chinese technologies, said a statement marking the end of the project in November last year. Under the training, 15 plant protection officers learned disease monitoring as well early-detection and laboratory-identification techniques along with how to detect and quarantine the fungus on imported bananas. The secretariat - also hosted by the FAO headquarters in Rome - said Cambodian farmers were therefore able to detect the disease at an earlier stage,' enabling them to implement control measures before it could spread and cause significant damage.' HOW IT SPREADS The fungus that causes TR4 attacks the roots of the banana, clogging its vascular system. Apart from infected plants, the fun gus can spread to items such as farm tools, shoes, clothes, animals and vehicles through contaminated soils. 'Irrigation and drainage water also play a critical role in its spread. Typhoons and other storms can also carry the TR4 fungus to new plantations,' the Global Network says. 'Once TR4 is in the soil, there are no effective treatments, chemicals or otherwise.' Source: Agence Kampuchea Presse