Facing threats from Panama disease, scientists are scrambling to save the beloved fruit.
Bananas are near perfect snacks. They're sweet and satisfying, high in potassium and other nutrients, and they come in their own convenient carrying cases. (OK, they may get mushy before you have a chance to eat them—but that's why they're only near perfect.) In recent years, however, scientists have started to raise concerns about the fruit's vulnerability to disease, and a new report from the journal PLOS Pathogens seems to confirm that notion. Bananas as we know them may be on their way to extinction, thanks in part to Panama disease, a fungus that essentially blocks the plant's ability to draw water. Why is a pesky little pathogen cause for such sensational words like extinction? Because it's happened before.
The bananas you eat are a bit different than those your grandparents ate. Until the 1960s, most eating bananas were the Gros Michel variety, a stouter and thicker cousin of the banana you'll see in the produce aisle today. The sudden change in the world's favorite fruit was owed to a previous strain of Panama disease that devastated Gros Michel plantations worldwide. As major banana crops withered, agricultural researchers were able to develop a new, seemingly resistant cultivar: Cavendish. These more slender fruits quickly became the standard replacement for Gros Michels, and have remained so ever since.
One thing that has changed since the switch to Cavendish is the fungus. A new strain of Fusarium fungi called Panama Tropical Race 4 is already affecting Cavendish crops in southeast Asia, Africa and possibly Australia. If the Panama disease epidemic of the last century is any indication, the fungus could very easily hop continents and oceans once again. This may seem like a small problem for your bowl of cereal in the morning, but it's a much bigger deal for parts of the world where bananas constitute a staple food in many diets.
The major issues facing banana farmers are the lack of effective, affordable tests for detecting Panama disease and the fact that, currently, there's no known method for killing the fungus. This means that most growers won't notice they've been infected until it's too late to quarantine the crop. The other factor compounding the problem is that Cavendishes are essentially clones. Ever notice your banana doesn't have seeds? Any fruit that's pollenated by nature needs them to reproduce, but Cavendish bananas are grown by transplanting part of a previous plant's stem. That means there's no genetic diversity to fight back against threats like Panama disease. The global banana trade is an $11 billion industry. If the fungus infects the crops of a country like Ecuador (which exports one third of all bananas worldwide), the economic toll alone would be devastating.
Fortunately, our knowledge of genetics and pathogens has dramatically increased since the 1950s. New types of fruits could still be cultivated, and awareness of the new threat, combined with only being a couple generations removed from the last epidemic, point to a more optimistic outcome for our beloved banana.
For some very important banana history and facts about Panama disease, you can check out this informative video from Sci Show: