Developing a quicker way to detect Panama disease (TR4) in bananas

Hort Innovation is a proud supporter of the Department of Agriculture, Water and Environment’s Science and Innovation Awards for Young People in Agriculture, Fisheries and Forestry.

The Science and Innovation Awards encourage young scientists, researchers and innovators with original projects that aim to keep Australia’s rural industries sustainable and profitable. The Science and Innovation Awards have already helped 261 young Australians make their ideas a reality and showcase their talent to the world.

One of these young Australians is Ryan Orr who was the recipient of the Hort Innovation supported 2021 Science and Innovation Award. We spoke to Ryan about his research into a method for early detection of Panama disease on banana-growing properties.

What is the challenge you are working to solve?

Panama disease (TR4) is a highly destructive disease caused by a soilborne fungus that can cut off the flow of nutrients and water to the leaves of banana plants, causing the leaves to wilt and go yellow, and the plants to die. The pathogen stays in the soil indefinitely, so growers need support to detect, contain and manage this disease.

Ryan says that “the biosecurity measures currently in use for detecting Panama disease can only identify the presence of the pathogen once disease symptoms have been expressed, in the same way that we usually only know if someone is sick when they develop symptoms.”

“One of the biggest problems with TR4 is the time between when the pathogen is introduced to a banana property and when the plants express symptoms. This can be an exceptionally long time – months or even years. By the time you’ve identified that your farm has Panama disease, it is possible that machinery and people have spread infectious material across the property.”

“Preventative measures, paired with existing containment measures, are essential to minimise this potential spread. This is where my research comes in. If we can identify the presence of the pathogen that causes the disease before the plants develop symptoms, then we dramatically reduce the chance of spreading the disease.”

What potential solution are you researching?

Ryan plans to develop a laboratory test to detect TR4 as early as possible, using the same PCR-based technology as that used to diagnose people with SARS-Cov2 (COVID-19). Disinfectant footbaths are a natural aggregation point for miniature soil samples collected from across the banana property – as employees walk around the farm, they collect soil on their boots and then this soil will be collected when they are sterilising their boots in the footbath.

“It’s a passive way of collecting soil samples from across the property,” says Ryan. “My research is about developing a method to collect, extract, and test the genetic material of organisms from the footbath to test for the pathogen that causes Panama disease.”

What are the next steps for the project?

This stage of research is a proof of concept to show that the method works before longer-term funding is sought for field trials and to develop the method for commercial use. Over the next six months, Ryan will be working closely with molecular-bio scientist and PhD candidate Daniel Browne at James Cook University to develop and test the necessary methodology.

Ryan and Daniel will slowly introduce additional factors to the testing environment to gradually create conditions representative of footbaths on banana farms.

“We’ll begin by testing different concentrations of the pathogen DNA in water to find out how much needs to be present in a sample to detect it,” says Ryan. “Then we’ll introduce the chemicals generally found in disinfectant baths to establish how that impacts our ability to detect the pathogen. Next soil will be added to take the testing environment even closer to real-life conditions, and then longer periods of time will be used to simulate footbaths that might be left for a week or longer before they are tested.”

Will the results of this research be of benefit to other industries?

While Ryan’s project is focused on Panama disease in bananas, he believes the technology could be applied to any sort of soilborne disease that affects agricultural crops. The ability to track where pathogens are in the soil will give growers a valuable early warning sign, meaning they can act before symptoms are expressed in their crops.