Climate Change and Coffee: Combatting Coffee Rust through Nuclear Techniques

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.”

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.