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Nature Communications published the results of a field trial of Cavendish banana plants engineered to be resistant to TR4, the fungal strain that causes Fusarium wilt in Cavendish cultivars. The trial site was a commercial banana plantation in the Northern Territory of Australia where TR4 has become endemic.

Two of the evaluated lines were still free of the disease after three years. One had received a resistance gene isolated from a wild relative of the banana, whereas the other had received an anti-apoptosis gene derived from a nematode.

By contrast, 67%-100% of the control banana plants were either dead or infected by the fungus after three years, including  GCTCV-218. According to the authors, the tissue-culture variant was as susceptible as the Cavendish cultivar Williams.

QUT's press release

Tropical race 4 (TR4) has been reported in Laos and Vietnam, where symptoms typical of Fusarium wilt have been observed as early as 2014.

Laos and Vietnam are two of the countries in the region that have seen a surge in Cavendish plantations set up by Chinese investors to meet the demand for bananas in China, where TR4 is present in all banana-producing regions. The other countries are Myanmar, Cambodia and Thailand.

A vegetative compatibility test confirmed the presence of TR4 on a banana farm in Australia's Tully Valley, the second such confirmation since March 2015. Earlier this month, Biosecurity Queensland had acted swiftly by issuing a biosecurity notice while waiting for confirmation. It was later revealed that the samples came from Australia's largest banana grower, who has indicated that production will continue despite the added costs on operation. The farm's spokesperson is confident that the incursion can be contained.

Addendum: A new case was confirmed on the same farm in July 2018.

The Cornell Alliance for Science announced that a banana genetically modified to be resitant to the Banana bunchy top virus is in its first year of confined field trials in Malawi. The banana was developed by Queensland University of Technology in Australia.

ABC Rural announced that Australia's gene technology regulator approved a field trial of genetically modified Grande Naine bananas (a Cavendish cultivar). They were modified to be resistant to the TR4 strain of Fusarium oxysporum f. sp. cubense, the causal agent of Fusarium wilt, better known as Panama disease.  Four of the lines that were part of a trial that was interrupted when the plants were removed under the Banana Freckle Eradication program will be screened along with new lines.

Related content

• Evaluation of TR4-resistant genetically modified Cavendish banana plants
• TR4-resistant GM bananas to be trialled in Australia
• Engineered for survival

Chemistry students at the University of Costa Rica developed biodegradable bunch covers, for which they won a prize at the Feria de Emprendimiento Desarrollo e Innovación. The main components are plant cellulose, cassava starch and chitin extracted from shrimp shells. The covers are five times more resistant than the conventional ones and are equipped with a system to gradually release pesticides. They take 18 months to disintegrate.

Genetically modified Dwarf Cavendish plants representing various combinations of transgenes and promoters were field trialed in Australia with the view of transferring the technology to East African highland banana cultivars in Uganda. While none of the lines in the plant crop met the target of 50% of the Estimated Average Requirement (EAR) for vitamin A in vulnerable populations, 11 lines exceeded the target in the ratoon crop. According to the authors, the results "demonstrate that, rather than there being a reduction of expression with successive vegetative generations as a result of transgene silencing, the trait was stable".

The results were published in Plant Biotechnology Journal.

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• Field trial of Golden Bananas
• Q&A on the provitamin A-fortified GM banana
• The provitamin A banana under attack by anti-GM activists
• Vitamin A rich GM bananas

Fusarium musea, a fungus associated with crown rot, a postharvest disease of bananas, has also been implicated in human infections in non-banana producing countries. PLOS pathogens published a Pearl (an article meant for a broader audience than its peer-reviewed papers) which reviews the current state of knowledge and proposes future avenues of research.

In an unprecedented move, the 166-hectare banana farm on which the TR4 fungal strain was detected in March 2015, will be shut down to protect Australia's banana industry now that the Australian Banana Growers’ Council (ABGC) and the owners of the farm have signed off on the buy-out.

In August 2016, the ABGC, which represents the interests of the country’s commercial banana growers, had received the green light from its members to increase the Plant Health Australia levy from 0.0103 cents per kilogram to 0.5 cents per kilogram to raise 3m AUD that, added to the 1.5m AUD grant from the Federal Government, would be used to buy the farm. But the purchase was put on hold while sick plants in another property were tested for TR4.

On October 21st, the ABGC announced that it would proceed with the buy-out after Biosecurity Queensland revealed that the samples had conclusively tested negative for TR4. Their objective is to destroy all the banana plants, upgrade the fences and establish a ground cover before the wet season, to prevent the spread of the spores by surface run-off.

The farm is located in the northern part of Queensland, where 95% of the country's bananas are grown.

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According to Banana Link, the rapid expansion of the Rainforest Alliance certification "has invited a growing suspicion that much of its success can be attributed to the laxity of the certification criteria and the undemanding nature of the certification process. This includes criteria that are difficult to test or are fulfilled easily because they are very much open to interpretation, while the auditing of certified farms is open to compromise, when all the parties involved have a financial or other interest in creating a good impression".

Two papers published in PLOS Genetics explore the genome of three fungi that attack the leaves of bananas ? including the causal agent of black leaf streak, better known as black Sigatoka. Understanding their evolution and how they interact with the banana plant could lead to the development  of tools to control these diseases.

The FAO published the results of an assessment of the impacts of climate change on the banana value chain in Ecuador. The biophysical analysis evaluated banana suitability under climate change scenarios; the impact of climate change on yields and disease incidence; and the carbon footprint and greenhouse gas emissions of banana production. The socio-economic analysis examined the national social policies to ensure a fairer distribution of returns to stakeholders across the banana value chain, especially with regard to smallholder farmers and banana plantation workers.

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Scientists at the Wageningen University's LEI research institute recently published the results of a study on the impact of Fairtrade certification on the lives of plantation workers. One of the authors, Fedes van Rijn, told OneWorld Research that as far as wages are concerned, they did not find a difference between certified and non-certified plantations. But they did see differences in terms of in-kind benefits, such as access to housing and clean water. Workers at Fairtrade plantations were also better informed about their rights and generally more satisfied with their standard of living. The scientists also released a summary of the study and Fairtrade's response.

Grist's food writer Nathanael Johnson weighs in on the carotene-fortified GM banana scheduled to undergo a feeding trial at the Iowa State University in the US. The project is a collaboration between Australian and Ugandan scientists. Their aim is to introduce to Ugandan subsistence banana farmers a genetically modified cooking banana with higher levels of beta-carotene, a precursor of vitamin A, than the cultivars that are an important part of their diet. Johnson asked experts questions ranging from Aren’t there simpler ways to address vitamin A deficiency? to Why are Americans so interested?.

The Malawi National Biosafety Regulatory Committee recently approved confined field trials of transgenic bananas, according to Crop Biotech Update. The confined field trials will be conducted at the Bvumbwe Research Station of the Ministry of Agriculture and Food Security for three years, from 2016 to 2018. The transgenic banana planting materials will be introduced from Australia, and evaluated for resistance against the Banana bunchy top virus. Because of losses caused by bunchy top, Malawi has been importing bananas from Mozambique and Tanzania to meet the country's demand.

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One year on since the detection of TR4 in a Queensland farm, there is a sense of achievement that the disease has been contained to that one farm, but also high expectations that scientists will find a way forward to farming with TR4. ABC Rural discusses with nematologist Tony Pattison some of the projects scientists are working on.

The one-year anniversary comes on the heels of the fourth detection of TR4 on the 166-hectare Queensland farm, which remains under quarantine. The detection involved a single plant which has been destroyed and will be followed by the destruction of surrounding plants.

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With average temperatures in Uganda expected to increase by 2 degrees Celsius in the coming decades, coffee, the country’s most important cash crop, is expected to suffer. According to a piece by IPS News Agency, areas below 1,300 meters will likely become unsuitable for Arabica coffee production, whereas those between 1,300-1,700 meters will be compromised for coffee unless production systems are adapted. Based on work done by the International Institute of Tropical Agriculture (IITA) and partner organizations, intercropping coffee with banana is one such alternative as shade from the taller banana plants can reduce temperatures for the coffee plants by 2 degrees Celsius or more. One of the disadvantages of coffee and banana intercropping is that it increases competition for water, nutrients and light, but these effects can be minimised by applying agronomic practices such as pruning and fertilization.

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The Trade for Development Centre (a Belgian Development Agency programme) reports the main findings of an investigation into how banana value chains in Europe operate. Published by BASIC (the Bureau for Appraisal of Social Impacts for Citizen information)   “Banana value chains in Europe and the consequences of Unfair Trading Practices” estimates that the 25% decline in wholesale prices since 2001 has translated into a loss of revenue in the countries supplying the EU at a time when both production and living costs have been going up. Meanwhile, retailers increased their share of the banana value to around 40%.

The report is based on research commissioned by Banana Link and Fair Trade Advocacy Office as part of the Make Fruit Fair consortium.

Even though tropical race 4 (TR4) has been detected in only one farm in Australia's north Queensland, it is also affecting the other banana growers. Besides changing the way they grow bananas, it has also had social and psychological impacts. Last August, ABC Rural talked to a Tully Valley farmer who explained how it had changed the way neighbours socialize with each other. More recently, CSIRO researcher Matt Curnock told ABC Rural that a survey of 600 banana farmers and other people affected by the situation revealed high levels of stress among a quarter of the respondents. The results of the survey, which also showed low levels of awareness in some parts of the community, will be used to write a public report on community well-being issues and plan future interventions.

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Dipping bananas that are 75% green in a solution of lysophosphatidylethanolamine (LPE - a natural fatty acid) for 30 minutes increased the bananas' shelf life by 1 to 2 days, writes Science World Report. According to the press release, LPE improves the shelf life by maintaining membrane integrity, reducing respiration, and slowing the breakdown of starch and cell walls during the ripening and senescence of the fruit tissue. The study was published in HortScience.