The deadly Race 4 (R4) strain of Panama disease that first struck the banana industry more than four decades ago has become a global issue for growers and scientists who are scrambling to find ways to control its spread. Last week, Dr Agustin 'Gus' Molina, a senior scientist and Asia-Pacific coordinator at Bioversity International, met with farmers and researchers in Australia to discuss the potential threat the strain could pose in the banana-growing state of Queensland. At www.freshfruitportal.com we speak with Molina about the current research and techniques that could save the global banana market from the fungus.

The Race 4 strain of the disease first appeared in Taiwan in the 70s and was later discovered in Malaysia in the early 90s, only to move across to Oceania where it was found in Australia's Northern Territory in 1999.

The R4 attacks most banana varieties, including the auspicious staple known the world over as the Cavendish.

"Asia is the centre of origin of bananas, so different pathogens that attack the banana have evolved here in Asia and that is why we have many diseases here that are not found in Latin America," says Molina.

"It [Race 4] is the most dangerous form of Panama disease. The Cavendish-based industry is very vulnerable because it’s based on just one variety and grown in one culture.

"For the Cavendish trade, whether for national trade like Australia, China, or export like the Philippines and Latin America, this is extremely vulnerable because it’s based on a single variety."

Papua New Guinea is one of a few countries in the Asia-Pacific still free from the R4, while the Philippines and China became a recent addition to countries with infected plantations. Molina believes that due to the disease’s nature of infection, its spread is slowed and therefore prevention is the key method of quarantine.

"The pathogen exists in the soil, so once the soil is infected, the root and stem are infected. The good news is that this fungus does not move through the air, like Sigatoka, but through the soil.

"So it moves slowly. The American countries don’t have it yet, so the best way is to quarantine and prevent the spread.

Australia - a global biosecurity leader

Despite recent changes in Northern Territory to lift banana quarantine measures, Dr Gus believes Australia’s biosecurity measures are one of the world’s most advanced.

"I always use the model of Australia when I talk in other countries, about your [Australia’s] efficiency in biosecurity and quarantine, because in spite of the fact that the Tropical Race 4 was in the Northern Territory as early as 13 years ago, it has not moved to the main growing areas in North Queensland because of the prevention measures that are in place," he says.

"This way of implementing biosecurity does not exist in the same intensity in other countries and that is the big difference. I think you [Australia] are very successful at keeping out the pathogen from the main growing areas."

He adds the country’s level of development is one of the key differences setting Australia’s farming apart from the rest, with smaller number of plantations and large growing areas.

"It’s easy to implement something like this in Australia, because of the different political social and economic structure.

"Meanwhile in other countries, you have so many small growers, but here is Australia you have very defined growers with 50-70 hectares and defined growing areas."

Molina believes however that mechanized farming practices in Australia are disadvantageous in controlling the spread of Panama disease.

"Here is Australia, you have mechanised farming…once the disease comes into the area it will spread faster, because you have tractors which would be moving the soil from one place to the other."

He adds Australia’s limited use of banana varieties, such as Cavendish, can lead to increased rates of infection.

"Also in other countries, they’re using a lot of varieties and the genetic diversity slows down the spread of the epidemic.

Molina noted however that Australia presents research opportunities that enable collaboration between governments, farmers and institutions.

"I look at the positive side of Northern Territory. You have here in Australia a place where you can do some research collaboration in terms of developing mitigation."

Current Solutions

Molina leads several projects across the Asia-Pacific, Latin America and Africa, to raise awareness and build partnerships with global experts and research institutions.

This is an industry issue, not only for Australia…it’s a global issue. That’s the reason why we at Bioversity International work with partners to address this issue."

"Within a country, there should be collaboration and partnership…and there should be an increase in investment for research."

He says the research into resistant varieties is shedding light into the future of the banana industry.

"We have very good indications now, that there are options available. In NT, we already have two or three semi-clonal variations from Taiwan that are being evaluated, which Bioversity International brought to this region. They are trying to use them commercially.

He also highlights that technological advancements are helping control the infection rate through early detection of the fungus.

"With the current technology, there are now molecular diagnostic tools to identify this pathogen. Nobody is now sending planting materials from one region to another.

"These technologies would delay, or even totally prevent the movement…then you have the continental divide. These are all impediments to the spread."

Molina is currently coordinating a network of national research institutions and councils in the Asia-Pacific, the Banana Asia Pacific Network, which aims to identify global and national agenda and developing projects that address the criteria.

He believes strong partnerships and collaboration through research will help banana industry players to confront the Panama disease.

"This is providing significant costs and efforts to produce bananas, but it will not kill the industry.

"If we continue to confront this problem with positive and constructive manner, I think we can manage this. We need to work harder."

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