What

Bye-Bye, Bananas?

A disease threatens the world’s most popular banana

DECEMBER 18, 2015

By Glenn Greenberg

Healthy bananas ripen on trees in Ica, Peru.

The world’s most popular type of banana is facing a major health crisis. According to a new study, a disease caused by a powerful fungus is killing the Cavendish banana, which accounts for 99% of the banana market around the globe. The disease, called Tropical Race 4 (TR4), has affected banana crops in southeast Asia for decades. In recent years, it has spread to the Middle East and the African nation of Mozambique. Now experts fear the disease will show up in Latin America, where the majority of the world’s bananas are grown.

“It isn’t there yet,“ scientist Randy Ploetz told TFK. He is one of the authors of the study, which was published in November in the journal PLOS Pathogens. “But our concern is that it will somehow jump the Atlantic, establish itself in the Americas, and cause some serious damage there.”

Easy to Spread

A. D'HONT/CIRAD

A banana infected with Tropical Race 4 (top) sits beside a healthy banana.

Once a banana plant is infected with TR4, it cannot get nourishment from water and nutrients, and basically dies of thirst. TR4 lives in soil, and can easily end up on a person’s boots. If the contaminated boots are then worn on a field where Cavendish bananas are grown, the disease could be transferred. “Once a field has been contaminated with the disease, you can’t grow Cavendish bananas there anymore,” Ploetz says. “The disease lasts a long time in the soil.”

Cavendish bananas are produced in mass quantities and are popular among consumers. “They’re what you buy in the grocery store, what you slice up and put on your cereal, and what your mom uses to make banana bread,” Ploetz says. “Consumers like the way Cavendish looks and tastes.”

But Cavendish is also particularly vulnerable to TR4. The banana is grown in what is called monocultures. “You see a big field of bananas and each one is...