Fusarium Wilt: Indonesia’s Silent Epidemic

By: Gert Antonio Tobing–Indonesian Science Affairs Fellow 2026

A fungal strain attacks banana production across the Indonesian archipelago. What does science say about it?

In Aceh, at the northern tip of Sumatra, farmers were planting new gardens of Pisang Barangan, a banana variety popularly known for its sweetness. To get started, they dug up young shoots from gardens nearby. “The seedlings looked healthy,” says Catur Hermanto, a plant disease researcher at Indonesia’s National Research and Innovation Agency (BRIN), who saw those gardens. No wilting, no yellow leaves. But some carried something deadly, Fusarium oxysporum, a fungus that can sleep in the soil for decades.

Fusarium wilt, also called Panama disease, is a silent killer. The fungus enters through the roots and blocks the tubes that carry water. The leaves turn yellow, then collapse. Cut the trunk open, and the inside is stained brown or black.

Last century it wiped out Gros Michel, the banana variety that once dominated the global market. Now a more aggressive strain, Tropical Race 4 (TR4), threatens the Cavendish sold in most supermarkets. Local favourites such as Barangan, Raja, Ambon and Kepok are also threatened. In the early 2000s, the Indonesian Institute of Sciences (now merged into BRIN) found that TR4 was found in almost all of the 15 provinces it surveyed.

Province’s banana production had fallen by about 60%, blaming Fusarium and bacterial wilt. In July 2026, Mandailing Natal in North Sumatra began preparing a four-hectare pilot plot of land to revive Kepok bananas, which local academics say have been declining for about 20 years.

The problem persists. In October 2026, Kosasih, head of horticulture production at East Kalimantan’s food and horticulture office, said the province’s banana production had fallen by about 60%, blaming Fusarium and bacterial wilt. In July 2026, Mandailing Natal in North Sumatra began preparing a four-hectare pilot plot of land to revive Kepok bananas, which local academics say have been declining for about 20 years.

Researchers are testing ways to slow the disease, such as rotating bananas with other crops and treating plants with silicon. But big challenges lie ahead. No banana yet fully resists TR4 and suits Indonesian tastes, and there is still no system to certify healthy seedlings.

A fungus that keeps winning

Fusarium comes in strains called races, and each race kills certain banana varieties. By the 1950s, one race had wiped out 40,000 hectares of Gros Michel in Latin America. Growers switched to Cavendish, which resisted that race, until TR4 attacked it. Hermanto describes a pattern: a new, more resistant variety arrives, and “it turns out the next variety is also broken by the next race.”

TR4 is now a global problem. Since 2018, the number of countries reporting it has risen from 16 to 26, according to the Alliance of Bioversity International and the Center for International Tropical Agriculture (CIAT). In the Philippines, about 15,000 hectares have been lost in recent years, nearly three-quarters of it belonging to smallholder farmers. One projection says TR4 could take out 17% of the world’s banana-growing area by 2040, some 36 million tonnes worth over US$10 billion. Another study in 2018 saw the spread of TR4 in South and Southeast Asia, along with Australia and even South America.

Where TR4 came from is debated. Arif Wibowo, a plant pathologist at Universitas Gadjah Mada (UGM), says bananas originated in Southeast Asia, so their diseases evolved there too. Hermanto is more cautious as people tend to claim origin from the earliest publications; he says, “but adaptation of living things can happen anywhere.”

What does it cost? No one has measured it nationwide, Wibowo’s 2025 review says. Hermanto’s 2011 paper offered a rough estimate: with a price of Rp1,000 a kilogram, the loss was worth up to Rp1.21 trillion in that year alone. That is an assumption, not a measured loss, says Hermanto.

Indonesia’s quiet epidemic

Hermanto led the most comprehensive survey of the disease in Indonesia, published in 2011 when he worked at the Indonesian Tropical Fruit Research Institute in Solok, West Sumatra. His team visited farms in 15 provinces between 2006 and 2009. On those farms, wilt had significantly infected banana tree populations. South Sulawesi (about 60%) and East Kalimantan (about 43%) were worst affected. About 63% of the fungus samples tested were TR4. His team has not repeated the survey, and he has no current national figures.

What does it cost? No one has measured it nationwide, Wibowo’s 2025 review says. Hermanto’s 2011 paper offered a rough estimate: with a price of Rp1,000 a kilogram, the loss was worth up to Rp1.21 trillion in that year alone. That is an assumption, not a measured loss, says Hermanto.

Many farmers cannot tell what’s killing their plants. In Gunung Kidul, Yogyakarta, farmers told Wibowo their bananas had Fusarium wilt when in fact it was bacterial wilt. Others nearby blamed Fusarium when it was actually pests. Extension officers, he says, now cover several districts each, so information rarely reaches backyard growers. For many families, bananas are just side crops.

What science can do?

Large plantations have fought back. A commercial farm in Lampung, which exports Cavendish, once saw its banana land shrink from about 7,000 hectares to about 2,000, Wibowo recalls. It recovered by uprooting infected blocks, planting pineapple for a cycle or two, then returning to bananas. Disease incidence is now under 5%, he says. But rotation is impossible for a farmer with a few plants.

Other tools are being tested. In Wibowo’s trials, planting Chinese chives alongside bananas cut disease incidence by up to 40%. In a greenhouse experiment, Arief Pambudi, a biologist at Universitas Al Azhar Indonesia, found that silicon helps Cavendish plants infected with TR4, where damaged tissue in the corm covered about 10% of the cross-section in silicon-treated plants versus about 30% without silicon, and roots kept their structure better. The 2025 study suggests silicon modifies the plant’s ethylene-based defence signals and protects root tissue.

Resistant bananas are further away. No banana is fully resistant, Wibowo says. French breeders created TR4-resistant types; however, the type was tailored for African taste, which Indonesian markets wouldn’t accept. In Mandailing Natal, academics from Universitas Medan Area say they are developing disease-resistant Kepok seedlings, and warn that infected soil can take up to 20 years to recover.

From lab to policy

Wibowo’s message to policymakers is for better quarantine mechanisms. Unlike citrus and coffee, bananas have no certificate to show seedlings are healthy, and he says the fastest spread comes from the seedlings themselves. It is important to quarantine infected areas. “Quarantine, yes, quarantine is important when it comes to the spread of diseases”, said Wibowo.

Pambudi added that it’s not just about raising a single resistant cultivar, but rather in figuring out how we can still keep our biodiversity. “So, not moving toward a monoculture where only a single cultivar is grown… after all, Indonesia’s true wealth lies in its biodiversity. How we can preserve that condition should actually be our strength”, said Pambudi.

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Gert Tobing wrote this article as a participant in the ISA Fellowship Program 2026.
He is a neuroscientist based in Jakarta, Indonesia. He earned a Bachelor of Science (B.S.) in Biology from the University of Indonesia and a Master of Science (M.S.) in Molecular Neuroscience from the University of Bristol, with research experience spanning neuroscience and molecular biology. As part of the ISA Scholarship Program, Gert will explore Biomni, a newly launched artificial intelligence (AI) agent capable of autonomously designing and conducting biomedical experiments, and what such a tool means for research capabilities in a country like Indonesia.