Coffee Leaf Rust: The Disease That Changed Coffee History

Few plant diseases have redrawn the map of a global crop the way coffee leaf rust has. In the 1870s, it ruined the coffee plantations of Ceylon, now Sri Lanka, and pushed the island toward tea. A century later it reached Brazil, and in 2012 it swept Central America, hitting smallholders hard. Coffee leaf rust is caused by the fungus Hemileia vastatrix, which covers the underside of coffee leaves in orange powder until the plant drops them.

Here is the timeline, the biology in plain terms and what farmers, breeders and roasters are doing about it.

Key takeaways

• Coffee leaf rust is a fungus that attacks only coffee plants. It originated in East Africa.
• In Ceylon, coffee land fell by about 80% in the late 19th century as planters switched to crops such as tea.
• By 1990 the disease was established in all major coffee-producing countries.
• The 2012–2014 outbreak in Latin America caused an estimated US$1 billion in damage, according to USAID.
• Resistant varieties, often bred from the Timor Hybrid, are the most durable defense.

In this article

1. What is coffee leaf rust?
2. Ceylon: the collapse that made a tea nation
3. How rust spread around the world
4. The 2012 Central American epidemic
5. How farmers fight rust today
6. FAQ

What is coffee leaf rust?

Coffee leaf rust, called roya in Spanish-speaking countries, is caused by Hemileia vastatrix. It is an obligate parasite, meaning it can only live on living coffee plants. British mycologists Michael Joseph Berkeley and Christopher Edmund Broome named it in 1869, from specimens sent from Ceylon.

How an infection works

1. Spores land on a leaf and need free water, such as dew or rain, to germinate.
2. They enter through the stomata, the tiny pores on the underside of the leaf. Infection can be completed within 24 to 48 hours.
3. Pale yellow spots appear on the upper surface; underneath, yellow-orange powdery spore masses form.
4. A single lesion can release 300,000 to 400,000 spores over three to five months, spread mainly by wind and rain splash.
5. Badly infected trees shed their leaves, cannot feed their cherries and can die back. The next year’s crop suffers too.

The fungus develops between about 16 and 28°C, and spore germination peaks around 21°C. That is why cooler, high-altitude farms have traditionally suffered less, and why warming temperatures are a concern, a link explored in our article on coffee and climate change.

Ceylon: the collapse that made a tea nation

In the mid-19th century, Ceylon was one of the world’s major coffee producers. Rust was first reported there in 1867, and within two decades the industry was in ruins. Historical data suggest production fell by about 75%, and the area under coffee shrank by roughly 80%, from 68,787 to 14,170 hectares. Planters nicknamed the disease “Devastating Emily.”

Many estates replanted with tea. By 1890 the island’s coffee industry was nearly gone, and the Ceylon tea industry that replaced it went on to become one of the world’s best known. One microscopic fungus helped change what Britain drank.

How rust spread around the world

Rust in Asia also pushed producers toward Robusta, which is naturally more resistant. That is part of why Indonesia and India grow so much Robusta today.

The 2012 Central American epidemic

For decades, Central American farms lived with rust at manageable levels. Then, in 2012, an outbreak spread across ten Latin American and Caribbean countries. Regional coffee output fell by about 16%. The US Agency for International Development estimated roughly US$1 billion in damage and more than 2 million people affected between 2012 and 2014. Guatemala declared a national emergency in February 2013.

Honduras was among the hardest hit, with about 80,000 hectares infected. Around 30,000 farmers lost more than half their production capacity and about 10,000 lost all of it. Since around 84% of Honduran producers are smallholders, the losses fell on families with little cushion. For context on that origin, see our Honduran coffee guide.

Temperature and moisture are the main drivers of rust outbreaks, and much of the region was planted with susceptible varieties such as Caturra, Bourbon and Typica, which left farms with little natural defense.

How farmers fight rust today

Resistant varieties

Plant scientists consider resistant varieties the most effective and durable control. Many descend from the Timor Hybrid, a natural cross between Arabica and Robusta found on the island of Timor in the early 20th century, which inherited Robusta’s resistance. Researchers at the Coffee Rust Research Center (CIFC) in Oeiras, Portugal, crossed Timor Hybrid selections with Caturra to create Catimor, the ancestor of many modern resistant lines. Newer options include F1 hybrids such as Starmaya, developed with the French research agency CIRAD.

Catimors long had a reputation for ordinary flavor, but careful farming and processing can produce very good cups. Rust resistance can also break down as the fungus evolves, so breeding never really ends. Our guide to coffee varieties explains the family tree.

Farm management

• Fungicides: copper-based sprays such as Bordeaux mixture are used preventively; systemic fungicides treat active infections. Chemicals can make up a large share of production costs.
• Pruning and spacing: better airflow lets leaves dry faster.
• Nutrition: well-fed trees, with adequate nitrogen and potassium, resist better.
• Renovation: replacing old trees with young, resistant plants, which takes years to pay off.

What it means for your cup

Every coffee you drink comes from a country that has dealt with rust. Sumatra has lived with it since the 1870s, Colombia and Costa Rica since the 1980s, and Honduras rebuilt after 2012. Buying from established origins and paying for quality helps keep farmers able to invest in healthy trees. Browse them all in our Single Origins collection.

Coffee leaf rust FAQ

Can coffee leaf rust affect the taste of coffee?

Indirectly. Infected trees lose leaves and ripen cherries poorly, which can reduce quality. Rust does not make roasted coffee unsafe.

Does leaf rust affect Robusta?

Robusta is generally much more resistant than Arabica, which is why it spread in rust-hit regions of Asia.

Can I get rust on a coffee houseplant?

It is rare indoors, because the fungus needs spores and wet leaves, but check any orange powder under the leaves and remove affected leaves.

Is there a cure for coffee leaf rust?

No permanent cure exists. Farmers combine resistant varieties, fungicides and good farm management to keep it under control.

Sources

1. Hemileia vastatrix, Wikipedia (citing USAID, APS and historical records).
2. Catimor: The Controversial Superhero of Coffee, Ozone Coffee.

Facts checked in October 2026.

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