Vanishing Bananas

Every year, more than 100 billion bananas are consumed worldwide, 47 percent of which is the classic yellow Cavendish cultivar. According to a recent report in ScienceAlert, a strain of the Fusarium fungus known as Tropical Race 4 (TR4) is causing an outbreak of a wilting disease commonly referred to as Panama disease, which threatens to eradicate this popular varietal. First discovered in Australia in 1997, TR4 has spread worldwide. The infection begins in the tree’s roots and ultimately disables its ability to absorb water or conduct photosynthesis. Because of its slow progression, experts believe the disease will take about a decade to completely wipe out Cavendish bananas.

Although there is no simple solution to TR4, scientists are exploring several options, such as genetically modifying the fruit to be more resistant to TR4, grafting Cavendish onto other trees to make them more resistant, and evolving Cavendish seedlings by exposing them to TR4 and selecting those that fare best. These may turn out to be short-term approaches, however, as the fungi could mutate.

The best solution may be for farmers to stop growing only one variety of banana. By increasing the genetic diversity of the world’s favorite fruit, bananas may become less susceptible to diseases. On the other hand, introducing a wider variety of bananas could drive up costs and would require an overhaul of ripening and transportation practices.