Banana: a key crop for food security that is under threat

Bananas, an essential crop for global food security and the subsistence of millions of small agricultural producers, face their most serious threat in decades: the Tropical Race 4 (TR4) strain of the Fusarium fungus causes a true pandemic in plantations and is devastating in several countries.

TR4, which causes a disease that spreads very easily, is already present in Latin America and the Caribbean. There is no known cure, which makes a coordinated effort by various actors from the public and private sectors essential to generate scientific knowledge, build capacity among producers and contain the disease, in order to ensure the continued production of a crop that is food. and source of income for a significant portion of the population, especially in developing countries.

This was stated by scientists Gert Kema and Chelly Hresko, two of the experts who have most investigated the topic in the world, in a conversation organized by the Inter-American Institute for Cooperation on Agriculture (IICA).

“It may be surprising to learn how important bananas are to so many people, especially vulnerable people whose food selection is limited. It represents up to 25% of the calories you consume daily. And it is grown in 135 countries, supporting the incomes of countless small producers,” said Hresko.

Hresko, responsible for Disease Research and Development Innovation and Agricultural Efficiency at the Bayer Biotechnology Organization, added: “The main difficulty we face is that we cannot rely on the magic of chemistry to get rid of this disease. All we can do, while developing scientific knowledge, is train producers on the best forms of containment. It is a very complex challenge.”

Kema explained that the TR4 strain of the Fusarium fungus attacks the Cavendish banana variety, which today covers approximately 50% of global banana production, 95% of export markets and is the only one that is massively commercialized in Latin America and the Caribbean, as well as in the West in general.

This variety has been dominant in global markets for around 70 years, due to its natural resistance to the so-called Fusarium Race 1, which had decimated the production of the Gros Michel banana, the most widespread until then.

“Cavendish has been such a wonderful solution for the last 70 years that there has been virtually no research into what exactly TR4 disease is and how crops can protect themselves from it,” reported Kema, who runs the plant pathology laboratory — the science that studies plant diseases — from Wageningen University, in the Netherlands.

“Therefore, it is not surprising that, as soon as this disease came to light, it quickly became a threat to all production. We now face a situation that, in some respects, is a repeat of the history that happened with the Gros Michel variety,” he added.

The specialist explained that the disease, now a global threat, was first detected in Jordan, but originated in Southeast Asia, just like the banana itself: “TR4 is a particular species of Fusarium that started in Indonesia and spread throughout the world. across the rest of Southeast Asia and is now moving west: India, Pakistan, the Middle East, Africa, and then Colombia.”

The presence of the disease in Colombia — the only country in Latin America and the Caribbean to date — was officially confirmed in 2019 by the Colombian Agricultural Institute (ICA), which detected it in plantations in the north of the country. There is no precise answer as to how and why it got there.

“It could also have been any other banana-producing country in Latin America or the Caribbean. It was completely random,” Kema said.

The scientist, who has 38 years of experience studying plant pathologies, explained: “We know that the disease is transmitted through the soil, but there is no reason to conclude that, with the transport of bananas, contamination spreads. We understand that the main reason for the spread is travelers and, in this sense, in the banana sector there are many risks, as workers often go from one country to another”, explained Kema.

Therefore, as a preventive measure, it is necessary to ensure the hygiene of those near banana plantations. “If you wear your boots on a plantation in the Philippines,” said Kema, “and then put them back on in Costa Rica, that is very dangerous. If the soil is contaminated, it will contaminate your shoes, your clothes, your tools.”

The expert suggested that producers reduce the presence of visitors to their plantations and recommended that, if they have no other alternative than to receive visitors, they should “arrive clean and leave clean”, so that there is no risk of them bringing or carry the disease.

Chelly Hresko added that the first disease caused by the Fusarium fungus, in the first half of the 20th century, which killed the Gros Michel banana variety, expanded at a much slower rate as, at the time, people traveled less around the world.

In this sense, the Covid-19 pandemic, with the severe travel restrictions it brought along, is a factor that could slow the spread of TR4.