Americas may be hit by catastrophic banana disease

Tropical Race 4 (TR4) of Fusarium wilt (aka Panama disease), attacks Cavendish varieties, which comprises 45 percent of the bananas that are produced in the world, said Randy Ploetz, a professor of plant pathology at UF/FAS Tropical Research and Education Center. The disease kills plants and is very difficult to control, he said. "Fusarium wilt has been a destructive problem for well over a century. Race 1 was responsible for the demise of the first export trades of bananas," Ploetz said. "Recently, TR4 moved from Southeast Asia to the Middle East and Africa."

Cavendish bananas are very resistant to race 1 but not TR4, Ploetz said. There is no other cultivar of banana to replace Cavendish if TR4 hits the Americas, Ploetz said. In 2011, combined global production of bananas was 145 million tons worldwide, with a gross production value of $44 billion, he said.

According to the Food and Agricultural Organization of the United Nations, in 2007 the United States imported 4,003,801 tons of bananas, or 25 percent of the world total. "The banana is arguably the world's most important fruit crop," Ploetz said.

Reports of TR4 have been documented in Jordan, Lebanon, Oman, Pakistan and Mozambique, Ploetz said. "It's not in the Americas yet, but if it moved from Southeast Asia to Africa and the Middle East, then a jump from these areas to the Americas is certainly possible," he said.

Researchers speculate that TR4 spread via Southeast Asian workers who helped establish banana plantations in other parts of the world, Ploetz said. "We are not sure how, but we believe that these workers transported the pathogen with them."

The only way to manage TR4 is to develop resistant bananas, Ploetz said. "Meanwhile, there is no cultural, physical, or biological treatments to manage TR4."