You are here

Climate Change and Coffee: Combatting Coffee Rust through Nuclear Techniques

Coffee leaves display symptoms of coffee leaf rust disease

Coffee leaves display symptoms of coffee leaf rust disease at the CIFC in Portugal. (Photo: I. Ingelbrecht/ IAEA)

The coffee industry generates approximately US$ 100 billion per year. But with climate change and the changing weather patterns that come with it, the conditions that were once suitable for coffee plants are deteriorating in many traditional growing areas; in addition, incidence of coffee leaf rust ꟷ a disease that kills coffee trees ꟷ is on the rise.

The IAEA, in partnership with the Food and Agriculture Organization of the United Nations (FAO), has been working with national experts to alleviate the stress of coffee leaf rust on coffee trees using nuclear techniques. A first for the IAEA, experts are being trained to use plant breeding techniques to develop coffee varieties that are resistant to the fungus that causes coffee leaf rust. This training is part of a five-year Coordinated Research Project where scientists from six countries are conducting research on disease resistant coffee plant varieties.

“Growers have been noticing the effects of climate change on their coffee crops resulting in lower harvests and the fact that erratic rainfall, which a lot of these coffee-producing areas are experiencing, favours the spread of disease,” said Ivan Ingelbrecht, Head of the Plant Breeding and Genetics Laboratory at the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture. “The arabica variety of coffee is usually grown in cooler climates, on the slopes of mountains in shaded areas, but now we are seeing the temperatures increase as you go up the mountain, which has an impact on the spread of diseases like coffee leaf rust.”

Farming coffee in Costa Rica

In Costa Rica, most coffee plantations rest on small to medium plots of land. These family-owned farms oftentimes rely on seasonal workers to pick the coffee beans by hand. This process is timely and intensive, requiring up to 14 000 workers from Costa Rica and Panama during the harvesting season.

But as climate change exacerbates weather patterns that are unsuitable for coffee plants, seasonal work opportunities diminish, impacting livelihoods. Changing rainfall patterns and rising temperatures have also been found to shorten the time it takes for a coffee plant with leaf rust to become infectious ꟷ increasing the rate of infection and the spread.

Working with the IAEA and FAO, the Coffee Institute of Costa Rica (ICAFE) has been researching the impact of coffee leaf rust throughout the country and how to manage it. With records since 2010 showing a rise in temperature and changes in rainfall patterns, coffee growers are finding that they cannot harvest their crops at the usual times.

“The reduction in productivity affects the income of growers, reducing the resources available to assist the plantation and putting the conservation of the farms for future generations at risk. This may affect the future model of land possession in our country,” said Reina Cespedes, a biotechnologist at ICAFE. “Advancing the genetics of coffee trees is essential to improve the quality of life for coffee-producing families, maintain land possession and contribute to environmental sustainability.”

Coffee research in Portugal

Portugal, also involved with the IAEA-FAO project, is home to the Coffee Leaf Rust Research Centre (CIFC). About 3600 samples of coffee rust from 40 countries around the world have been evaluated at the CIFC, where scientists identified 50 different races of coffee leaf rust across 23 varieties of the coffee tree. Within the IAEA project, three new races of the coffee rust pathogen were identified. Research into this collection of global coffee rust will facilitate the identification of a variety of coffee plant that is resistant to coffee rust ꟷ a tall task considering the variety of coffee rust species.    

“We were first made aware of the impact changing weather patterns were having on coffee harvests in 2011 from coffee breeders, pathologists and technical bulletins from coffee growing countries,” said Vitor Varzea, plant pathologist at CIFC. “It is urgent to find and characterize new varieties of coffee plants that are resistant to coffee leaf rust which can then be extended to other countries.”

The project’s research into advanced varieties of coffee plants will have the potential to combat the challenges that climate change presents, such as the disease outbreaks seen with coffee leaf rust. Through implementing plant breeding techniques in coffee, FAO/IAEA and researchers from Central and South America, China and Europe are developing new varieties resistant to coffee leaf rust. While coffee plant breeding is a first for the IAEA, plant breeding techniques have been used to enhance food security around the world with over 1000 improved plant varieties released in the past decade, including in cassava, soybean, tomatoes and rice.

Stay in touch