Coffee: a vulnerable crop

In connection with our trip to Colombia (which is getting close!), we wanted to mention something that has quite worrying repercussions for our daily coffee. Like most plants, coffee is under constant threat from various diseases and pests—which are getting more and more devastating in the context of climate change and globalization.

Leaf rust

Leaf rust has been known for decades, and has already wreaked havoc worldwide. Rust is caused by a fungus that attacks the leaves of the coffee plant, giving them an orangey hue, hence the name rust. The result? Every leaf on the bush may be destroyed, which translates into no fruit produced and no coffee.

Ever wondered why the British are such hard-core tea-drinkers? Well, it’s partly due to a leaf rust epidemic that hit the former British colony of Ceylon (now the country Sri Lanka). Coffee growing had to be completely abandoned, cutting off the entire British coffee supply. They switched to tea.

Leaf rust first appeared in Central America in 1976 and has since raged in a number of countries, notably in Colombia since 2008. A number of factors foster its development:

• The high temperatures observed in recent years allow the disease to survive and do its damage even at high altitudes.
• Winds help the fungus spread over great distances.
• Plantation shade levels need to be considered. Plots in full sun are more likely to develop the disease than shaded ones.
• We must consider the possibility that the disease has evolved over time, becoming more resistant and aggressive

Broca (coffee berry borer)

The coffee berry borer is another threat to coffee production, and it’s far from minor. Native to Africa, this small (2 mm) beetle is now found in all of the world’s coffee-producing countries, with those in the Americas being the most susceptible. It bores right into the coffee berry and spends nearly its entire life inside, drilling tiny tunnels in which it reproduces copiously. These tunnels also allow diseases to enter the bean. The result? The bean deteriorates, losing its aromas, and the fruits fall from the bush before ripening. The problem with broca is that it is closely linked to climate change: the hotter the climate, the shorter the borer’s life cycle and the more desperately it reproduces.

Fighting diseases and pests

There are a number of ways to fight these problems. Chemical treatment is one, obviously—particularly insecticides against the coffee berry borer. But the organisms adapt and the chemicals seem to have less and less effect. Some biological controls are also used, such as inoculating the crop with bacteria that are toxic to the insect, to eliminate the pest without ill effects on the coffee.

Colombia has an advantage in the fight against coffee diseases and pests: the Cenicafé research centre (we talked a bit about this in a previous blog).

This organ of the FNC has been in place since 1938. Its goal is to develop knowledge and new technology in the coffee sector. Specimens of 38,000 different coffees are preserved at Cenicafé, where they are studied to learn how to fight pests and diseases. In the early 2000s, Cenicafé thus created a brand new coffee variety: Castillo. The result of years of cross-breeding and testing, the variety is more productive and, above all, has better rust resistance. It was launched in 2005, but in 2011, the year of Colombia’s worst rust epidemic, only 25% of the country’s coffee bushes were of this variety. Note that it takes at least 5 years for a coffee bush to reach optimal yields, slowing the variety’s introduction at plantations.

The future of coffee remains threatened. Diseases and pests are adapting, becoming more resistant and spreading faster. Indeed, Castillo is already starting to fail: leaf rust is managing to develop on bushes of the new variety. Research is progressing, but changes in agricultural practices (shading, fertilization management, discontinuation of chemicals) will be needed to save harvests and let us continue enjoying a good cuppa.