The vibrant yellow, potassium rich fruit we all know and love is facing grave danger. Bananas may be moving towards extinction from the epidemic dubbed Panama disease. This deadly disease is the fungus fusarium, and it's a pathogen in the soil that affects the roots of banana crops.
The fungus produces spores that can live in soil for years, once an area becomes infected, it's almost impossible to grow bananas on it. Treatments to the soil are too dangerous for the environment and are banned almost everywhere. It seems the only way to save the banana industry is to develop varieties that are resistant to fusarium.
This story has played out before. The banana cultivar, Gros Michel, officially went extinct in 1965 after succumbing to an earlier strain of Panama disease. This led to the development of the Cavendish banana, which was resistant to the strain that brought about the Gros Michel's demise. The Cavendish is what we've all grown up eating, and it's smaller, more delicate, and apparently less tasty than the Gros Michel.
As a monoculture, all Cavendish bananas are genetically identical. This helps with the efficiency of mass production and distribution. However, if something goes wrong, it can have catastrophic effects as every banana will be susceptible.
History appears to be repeating itself as a new strain of Panama disease, tropical race 4 (TR4), is ravaging the Cavendish banana cultivar. Discovered in 1990 in Taiwan, TR4 remained concentrated in Asian nations such as China, Malaysia, Indonesia and the Philippines. It later spread to northern Australia, and in 2013 it was confirmed in both Jordan and Mozambique. Since the strain was discovered tens of 1,000s of hectares worth of banana plantations have been destroyed.
95 percent of banana exports are Cavendish bananas, and in 2012 banana exports totaled $7 billion. Bananas are a major cash crop for many developing nations, and TR4 is threatening the livelihood of millions of people.
It seems the key is to develop a cultivar resistant to TR4 and adopt it as the industry standard. This is, of course, easier said than done and it only pushes the problem into the future as new strains of Panama disease arise. Unfortunately, it seems scientists don't fully understand the genetic makeup of the fungus and how to successfully combat it. If left unchecked, we may face a world devoid of the delicious banana and millions of people will lose their sole source of income.