Bananas are the world’s most popular fruit, and in North America, they are a cheap, healthy source of food for many. However, according to plant pathologist Steve Savage, a new soil-borne pathogen is destroying banana crops in Asia, Australia and Mozambique, and it might be only a matter of time before someone inadvertently transports it to the Americas.
“There has been a little work on a solution, but nothing close to what would be needed to protect the future supply of this popular fruit or the jobs of a great many people involved in growing it and shipping it,” writes Savage, who holds a Ph.D. from University of California Davis.
It is not the first time the Americas have faced a serious threat to their banana supply.
In the 1950s, a type of fusarium wilt caused serious repercussions in the banana industry.
At that time, the majority of banana exports to the United States and Canada were a variety called Gros Michel, or Big Mike, grown in plantations around the world.
The wilt, called Panama Disease, first hit Brazil before wiping out vast tracts of banana crops on South American and African plantations. Transmitted through soil and water, the fungus could live dormant for 30 years.
Panama Disease was devastating and costly to producers who were forced to grow other disease-resistant varieties of bananas.
As a result, the Americas began importing a variety of banana called the Cavendish, which was found mainly in Thailand and Asia. The Cavendish variety was resistant to disease and suitable for shipping, which made it a popular choice for exporting.
By the end of the 1970s, the Cavendish bananas were being grown in several places around the globe. However, in the 1980s, many of the plants in Malaysia began to die. It appeared that a pathogen was entering the roots, causing leaves to discolour and choking off the water supply. After several years, scientists determined it was a new strain of Panama disease, called F. oxysporum, later named tropical race 4.
Since its discovery, it has spread to Pakistan, the Philippines, Indonesia, Africa and Australia. Plant scientists throughout the world are searching for ways to modify the banana, making it resistant to Panama disease and other fungal, viral and bacterial afflictions.
Scientists are working to create a hybrid banana that will be resistant to disease while others are exploring the addition of other plant genes to make a hardier fruit. The challenge, of course, is producing a fruit that tastes good, travels well, ripens in the right time frame and can be grown in large quantities.
Until then, we might have to prepare for another shortage of bananas on the grocery store shelves.