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Diagnostic tests have confirmed the presence of tropical race 4 (TR4) on another Tully Valley banana farm. The plant showing symptoms of Fusarium wilt was spotted in August by Biosecurity Queensland officers during routine surveillance.

It's the fifth property to test positive since TR4 was first detected in Queensland in March 2015. The property is in close proximity to the other four confirmed properties. The second and third detections data back to July 2017 and February 2018. The fourth farm was confirmed in February of this year.

Archaeobotanical analyses (mainly starch granule and phytolith) of an abandoned agricultural terrace on Mabuyag, an island in the Torres Strait separating Australia’s Cape York Peninsula and the island of New Guinea, found evidence of banana cultivation from at least 2,000 years ago.  The authors of the study say that bananas were probably cultivars from New Guinea, a centre of banana domestication, rather than from wild bananas growing on Australia, wild bananas being absent in Mabuyag. Additionally, phytoliths typical of banana seeds were not observed in the microfossil assemblage, further supporting a scenario involving the introduction of cultivars.

The Torres Strait is one of the few regions in the world where hunter-gatherers and horticulturalists coexisted. The lead archeologist said that this study "has implications for neighbouring Cape York and provides the methodology for investigating forms of horticulture practiced by Aboriginal Australians. Perhaps Aboriginal Australians experimented with vegetative propagation of banana and yam? The problem is, no one has done the work to check."

The first report of tropical race 4 (TR4) in the French overseas department of Mayotte is published in Plant Disease. The fungus that causes Fusarium wilt was isolated from two cultivars 'Baraboufaka' (Bluggoe subgroup ) and 'Kissoukari' (Silk subgroup). The plants sampled were from two adjacent plots in Poroani, a village in the southwestern part of the Grande-Terre island. The symptoms were first observed in September 2019. It was the first time that the first incursion TR4 in a country was detected on a cultivar other than a Cavendish one.

Three additional positive cases have since been found in the localities of Koungou  and Bouéni, including a Cavendish cultivar known locally as 'Kontriké'.

The NPPO of France informed the Secretariat of the European and Mediterranean Plant Protection Organization in January 2020.  Mayotte is part of the Comoros archipelago, located off the coast of Mozambique, which also has TR4.

After an almost two-year hiatus, the presence of tropical race 4 (TR4) was confirmed on a fourth banana farm in Queensland, Australia. Five plants showing symptoms of Fusarium wilt were detected on a Tully Valley property during routine surveillance in late January. The farm is located in the vicinity of the previous incursions .

The grower already had good on-farm biosecurity measures in place and, with support from Biosecurity Queensland officers, was able to resume trading within four days.

Tropical race 4 (TR4) is continuing its spread through Western Asia. In 2019, it was confirmed to be in Turkey. According to the first report in Plant Disease, symptoms of Fusarium wilt were first observed in March 2018 during a survey of banana greenhouses along the Mediterranean coast. The disease incidence on the Cavendish cultivar 'Grand Naine' was 18%, 86% and 10% in Alanya, Anamur and Gazipasa, respectively. The PCR-based diagnostic test specific to TR4 was used and pathogenicity tests were conducted.

On August 8, the Colombian agriculture and livestock authority (ICA) confirmed the presence of tropical race 4 (TR4) in La Guajira, a coastal department in the northern part of the country. The next day, ICA declared a phytosanitary emergency. This marks the first official report of TR4 in Latin America.

Six farms have been quarantined and most of the plants on an area of 175 ha have been destroyed. The confirmation came after receiving positive results from samples analysed in the Netherlands.

One of the better tasting 'Goldfinger' mutants (Source: ABGC)

TR4 is giving FHIA-01 a second chance of being adopted by consumers. The TR4-resistant improved hybrid was produced by the Honduran Agricultural Research Foundation, better known by its acronym FHIA. After a promising start when it was marketed as 'Goldfinger' in Australia, the big supermarkets removed it from their shelves in 2009. One reason given for its commercial failure is that it failed to appeal to consumers.

Following incursions of TR4 in Queensland, a project was launched to improve the eating characteristics of 'Goldfinger' by exposing it to gamma radiation to induce mutations. The Australian Banana Growers' Council reports that 20 elite variants have now been selected from the original 630 irradiated plants. They will be sent to the Northern Territory to be screened against TR4 to ensure that they are still resistant to the fungal strain.

Israel's NPPO has provided an update to last year's announcement that TR4 had been observed at two separate locations in 2016 and susbsequently declared eradicated after the implementation of containment measures.

The disease was recently discovered at a number of sites close to one of the two locations in the eastern/southern Lake Galilee area. As before, the infected sites have been confined and placed under strict supervision by the NPPO. The infected banana mats, as well as the symptomless ones in a five mats radius, have been fenced off and the plants destroyed.

The plantations with infected sites have also been fenced off, and have had their access restricted. Entry is allowed only under strict quarantine conditions. Water ditches have been dug around the fenced areas to prevent the spread of spores in rain water.

The pest status of TR4 in Israel has been amended to: Actionable, under eradication.

The latest installement of the Biosecurity Queensland newsletter includes an item on the options for farming on TR4 affected land. If a grower has TR4 on their farm and they want to use a section of land to farm other crops or manage livestock, they need to meet certain biosecurity requirements. The TR4 programme has produced factsheets on managing the risks for mixed farming and cattle grazing.  

In another news, scientists analyzing 451 samples of tissue from the upper part of the banana plant and fruit have re-confirmed that TR4 does not infect the fruit.

The Zimbabwean government has started clearing shipments of green bananas from Mozambique, where TR4 is present, destined for Zambia. The Zimbabwean Department of Plant Quarantine in the Ministry of Lands, Agriculture, Water, Climate and Rural Settlement had initially refused passage for fear that it would spread the fungal strain that causes Fusarium wilt in Cavendish bananas and a wide range of cultivars. The shipments were authorized to go through Zimbabwe after "research [indicated] that green bananas cannot spread [Fusarium wilt]", overlooking the risk posed by the trucks carrying the bananas.

Factors associated with the spread of the causal agent of Fusarium wilt.

As the authors of a paper on the epidemiology of Fusarium wilt point out: "Long distance dispersal of Fusarium wilt is mainly due to anthropogenic-related factors." The main ones, including vehicles, are illustrated in Figure 3 of the paper.

Australia's Northern Territory has been declared free of Banana Freckle.  The proof of freedom was handed down on 1 February 2019.

Banana Freckle. Photo by J. Liberato, DPIF

The fungal strain, Phyllostica cavendishii, had been detected in July 2013. The National Banana Freckle Eradication Program was launched in October 2014 and carried out in four phases over three years.

The Program was Australia’s largest cost-sharing emergency plant pest response under the National Emergency Plant Pest Response Deed. Banana growers across Australia funded half of the costs of the Program through a levy.  Funding was also provided by federal and state governments. The Northen Territory's Department of Primary Industry and Resources also provided financial and in-kind support.

The strain, which is capable of infecting Cavendish cultivars, has not been found elsewhere in mainland Australia. Banana freckle will remain a declared pest in the Northern Territory.

The Queensland Department of Agriculture and Fisheries has released the review of Biosecurity Queensland's Tropical race 4 (TR4) programme conducted by ACIL Allen Consulting. It had commissioned the independent review to establish on what basis the programme should continue.

The programme started in 2015 as an emergency response to the identification of TR4 in Tully Valley. Once it was established that TR4 could not be eradicated, the programme shifted to control and containment.

• The efforts of the programme, government, industry and others have been successful in containing the impact of TR4 to three sites in one location in the Tully Valley;
• The programme has successfully established arrangements that allow infected properties to continue producing bananas and access/supply their markets;
• Through “buying time” for industry and regions to adapt to TR4 the estimated net benefit of the programme is $2,126.1 million in 2017-18 dollars which equates to a benefit-cost ratio of 39.2:1;
• Without the programme it is likely the impact of TR4 will be more widespread and happen sooner; 
• The programme should therefore continue on the basis the industry and regions benefit from banana production;
• The programme needs to be placed on a 3-5 year funding and planning horizon to operate effectively; 
• The current objectives are well constructed reflecting the need to implement activities and simultaneously developing an enduring system with industry to do so; 

• All the elements are required to deliver on the programme’s objectives and considerable effort has been put in place to develop the policies and procedures to implement them.

States (in red) where TR4 has been observed: 4-Bihar; 27-Uttar Pradesh; 14-Madhya Pradesh and 7-Gujarat.

Even though it has been known to be in India since at least 2015, in the State of Bihar, the presence of Tropical race 4 (TR4) in the world's largest producer of bananas had not been officially confirmed. It now has with the posting on 27 November 2018 of a First Report in Plant Disease.

The isolates were collected from symptomatic plants in the State of Uttar Pradesh where, in June 2017, symptoms of Fusarium wilt had been observed on 'Grand Naine' in the Faizabad district. Further surveys confirmed the presence of TR4 in the districts of Kushi Nagar and Ambedkar Nagar.

The fungal strain has also been reported to be in the States of Madhya Pradesh and Gujarat.

The British television channel ITV has reported that the fungal disease which has been wreaking havoc in Southeast Asia’s banana plantations and beyond has found a home at the Eden Project’s Rainforest Biome in Cornwall, England. Plant pathologist Dr Rachel Warmington told ITV news that they were surprised to find Fusarium wilt in their banana exhibit, but have since used the  presence of the fungus as an opportunity  for research.

Eden Project's Rainforest Biome. Credit: Eden Project

Warmington confirmed to ProMusa that the fungus in question is Tropical race 4 (TR4). “It was identified in 2009, when the disease was first observed in the banana exhibit. We changed the plants and the soil, but the fungus reappeared in 2015 in a different part of the biome where there are also banana plants. We removed the affected varieties, 'Pisang mas' and 'Pisang Masak Hijau', a Cavendish cultivar. We also planted Allium tuberosum (Chinese chives) in the affected area to help suppress the disease and limit the impact on the remaining bananas. Eden Project is also collaborating with the University of Exeter on several research projects looking at biocontrol measures."

Warmington added that the UK’s Animal and Plant Health Agency is aware of its presence, even though it is not a notifiable disease in the UK. “Our protocols for managing the biosecurity around TR4 are the same as our biosecurity measures for the notifiable UK diseases we have on site.”

If TR4 has found its way to the Eden Project, it is possible that it is also present in other European gardens. “It is certainly an indication that the disease is likely to be moving in the amenity horticulture trade and botanic garden collections,” says Warmington.

Biosecurity Queenland announced that it has developed a system of certification for farms infested with Tropical Race 4  (TR4) that meet the requirements for interstate and intrastate quarantine purposes (Inspection of bananas for freedom of soil and plant material). The system allows accredited businesses to certify their fruit consignments without putting the wider industry at risk. Accredited farms will be visited by biosecurity officers to audit the fruit inspection process and ensure that biosecurity requirements are being met.

In May 2018, Israel's National Plant Protection Organization (NPPO) officially declared that Tropical race 4 (TR4), the fungal strain that causes Fusarium wilt in a wide range of bananas, had been eradicated from Israel.

In 2016, symptoms of the disease on the cultivar 'Grande Naine' (a Cavendish type)  were observed by farmers from Shfeya (Carmel coastal plain). Two months later, similar symptoms were also observed by farmers from Kibbutz Ein Gev, along the eastern shores of Lake Galilee. Samples were collected from symptomatic banana plants and sent for diagnosis  to the Plant Protection and Inspection Services of the Ministry of Agriculture.  Fusarium oxysporum f. sp. cubense was isolated from  symptomatic tissues and identified by PCR in July 2016. TR4 was confirmed by sequencing different regions of the genome (28S  ribosomal RNA, a putative pathogenicity protein gene, and TR4 marker genomic sequence). This was the first report of TR4 in Israel.  

The two outbreak areas were confined and placed under strict supervision and surveillance by the Israeli NPPO. The area was fenced and cordoned off. All affected plants were destroyed and irrigation terminated. Intensive surveys in adjacent plots conducted since 2016 did not detect the pathogen and no new incursions have been reported. The NPPO therefore concluded that TR4 had been successfully eradicated.

The Hindu Business Line reports that Tropical race 4 (TR4), the fungal strain that causes Fusarium wilt in Cavendish cultivars and a wide range of other types of bananas, has spread alarmingly accross India. First found in 2015 in the state of Bihar, in the northeastern part of the country, it has now spread to the states of Uttar Pradesh, Madhya Pradesh and Gujarat, on the west coast. The article says that banana farmers in the country are not aware of the serious nature of TR4.

For the first time, scientists have been able to infer the origin of incursions of the Tropical race 4 (TR4) fungus that causes Fusarium wilt in Cavendish bananas, as well as many other types. In a paper published in Frontiers in Plant Science, the scientists not only confirmed the presence of TR4 in Myanmar, they also uncovered molecular evidence that this particular strain, as well as the ones present in Laos and Vietnam, were likely introduced from China. Their analyses also revealed that the TR4 strains in the Philippines and Pakistan are closely related, and that the TR4 incursions in Lebanon and Jordan are associated.

The authors of the paper underscore the need for awareness campaigns and the implementation of validated quarantine measures to prevent further dissemination of TR4.

The report of a suspected case of Tropical race 4  (TR4) in Queensland, Australia, has been confirmed by Biosecurity Queensland. This is the third such case since the first report of TR4 in Queensland in early 2015. The property on which the fungus was first discovered has since been bought out by the industry and shut down. The second incursion of the disease was found in July 2017 on a property owned by one of the largest growers in the country.

The Minister for Agricultural Industry Development and Fisheries attributed minimal farm downtime on the third infested property to a prompt response by Biosecurity Queensland officers and the farm already having an established on-farm biosecurity plan.

In Queensland, infested farms must abide by biosecurity protocols to continue trading, which explains why the rate of spread has been extremely slow compared to worlwide experience.

According to scientists who visited Laos last October, TR4 may have been introduced in the country through infected nursery plants. As reported in The Laotian Times, the scientists spent 3 days surveying plantations of Cavendish plantations along the Vientiane-Vang Vieng road axis. A 45-hectare field established in 2014 for export to China had lost half of its production area due to a severe outbreak of TR4. Chinese managers told the scientists that the disease had appeared soon after planting tissue-culture plants imported from China, where TR4 is present. The scientists suspect that the initial outbreak was due to infected nursery plants imported from China. The presence of TR4 in Laos also threatens the susceptible varieties grown by smallholder farmers and sold in local markets.