Organic Banana Cultivation Cannot Escape Panama Disease

One of the most important growing areas of organic bananas, the Chira Valley in Peru, is being hit hard by the dreaded Fusarium wilt. Once this disease (also known as Panama disease) is present on a plantation, growers will not be able to grow Cavendish bananas or other Fusarium-susceptible bananas for decades. Wageningen University & Research and partners are therefore working on a solution in various areas: rapid detection, new varieties and new cultivation methods.

“In the Chira Valley, 8,000 small farmers grow about 10,000 hectares of organic bananas. The area produces 25% of the global supply of organic bananas. The presence of Tropical Race 4 (TR4) - one of the Fusarium soil fungi that cause Fusarium wilt - is therefore very worrying,” says Gert Kema. As professor of phytopathology, he leads the team that searches for solutions.

For the time being, this Fusarium species cannot be controlled. Once it strikes, the crop is destroyed and the soil is contaminated and unsuitable for growing bananas for many years. “The variant started in Southeast Asia, but has spread to 16 new countries in the last decade,” he said.

Quick discovery is crucial
Rapid detection of new infections can slow the spread. Wageningen scientists previously developed a rapid field test. Within an hour it will be clear whether there is an infection.

“We are now working on a system to map risk areas. The Chira Valley serves as a case study. The only way you can do this is from the air. The area is large and there are parts where you cannot or are not allowed to go. That is why we took and analyzed 133,700 aerial photos in twelve flights with a small plane,” says the banana expert.

The entire area depends on one irrigation system. In addition, flooding occurs in some parts. Because Fusarium can spread through water, it is therefore vulnerable. “We have mapped the flood-prone areas and started taking samples on the spot. This revealed more than 200 Fusarium infections . That is very disturbing,” says Kema.

According to him, growers basically have few options to contain the disease. They cut down infected plants, but that doesn't help enough. “When you see it, it's already too late. Then it becomes almost impossible to control it.”

Monoculture of one race
It is a big blow that the disease has reached the area. The area is ideal for organic cultivation because it is so dry. This means that the other dreaded banana disease, Black Sigatoka, does not stand a chance. This disease is caused by a leaf fungus and causes high and increasing use of antifungal agents in conventional bananas.

The problems with both fungi are largely caused by the fact that one variety is mainly grown all over the world: Cavendish. Wageningen University & Research is working with Yelloway, the company of Chiquita, KeyGene and MusaRadix to develop new varieties that are more resilient or resistant to the fungi. Kema expects these to be available in 2028.

Cultivate the soil
But time is running out. Fusarium continues to advance. “Thousands of hectares have now been written off in the Philippines. You won't be able to grow Cavendish there for decades. The fungus remains present in the environment for that long,” says the professor.

A new cultivation system is therefore being developed: banana plants in containers with an organic substrate. That now seems to be a realistic option for the hard-hit areas. “Getting crops out of the ground is a real solution. It could even lead to an increase in production," Kema expects.