The beloved yellow fruit is in danger.
Enjoy your smoothies and pancakes while you still can; bananas could soon disappear. According to The Conversation, a disease known as Tropical Race (TR4) is threatening banana crops in the Middle East, Africa and many Southeast Asian countries.
This is not the banana industry’s first encounter with disease. In the 1960s, a fungal pandemic known as Fusarium wilt (Panama disease) almost wiped out the world’s preferred banana breed, Gros Michel. Fusarium wilt, which prevents banana plants from absorbing water and nutrients, is hard to control; it spreads easily in soil and fungicide applications have not been effective. After the pandemic, producers replaced Gros Michel bananas with a variety called Cavendish.
Unfortunately, Cavendish bananas are not immune to fungal disease. Black Sigatoka, a disease caused by a pathogen called Pseudocercospora fijiensis, attacks the plants’ leaves, causes cell death and reduces fruit production. If Black Sigatoka is not controlled, banana yields can decline by 35 to 50 percent. It's possible to manage Black Sigatoka with a combination of leaf pruning and fungicide application, but that's not a long term solution. Fungicides are hard on the environment, promote resistant strains and can also put banana workers at risk for health complications. The prevalence of Black Sigatoka, along with the rise of TR4, signals trouble for Cavendish bananas.
Luckily, TR4 has not yet made its way to Latin America and the Caribbean, so scientists still have time to find a replacement banana breed. Researchers have now identified the genome sequencing of both the banana and the fungi that cause Fusarium wilt and Black Sigatoka, which will help pinpoint disease-resistant genes in wild and cultivated bananas.