Is Coffee Leaf Rust Due to Climate Change?

It is fashionable these days to blame any natural phenomena on global warming. With this in mind we ask a question. Is coffee leaf rust due to climate change? This is a pertinent question as Arabica coffee production has been devastated in several nations in the Western Hemisphere due to coffee leaf rust. There is a strong argument that temperatures are up and there certainly is a high incidence of leaf rust, la rolla in Spanish, devastating coffee crops. Over two thirds of coffee consumed worldwide is Arabica coffee. The other common variety, Robusta, is resistant to leaf rust but generally considered to be an inferior coffee. Let us take a look at the history of coffee leaf rust and efforts to control it such as with Colombian rust resistant coffee .

La Rolla

Coffee leaf rust is a fungal disease. It wiped out coffee plantations in Asia in the middle of the 19 th century. The country of Ceylon (Sri Lanka) was a coffee producer before the leaf rust drove planters to grow tea! The disease spread from the East Indies to South Asia and Africa and eventually arrived in the new world, almost a century later around 1970. Today coffee leaf rust threatens the livelihoods of coffee growers and workers throughout Central America. Due to foresight and hard work a country such as Colombia has produced a couple of leaf rust resistant strains over the last quarter of a century and greatly reduced the incidence of the plant disease in that country. Our original question was this: Is coffee leaf rust due to climate change? If that is the case you need to make the case for climate change in South Asia, the East Indies, and East Africa more than a century ago!

Dealing with Coffee Leaf Rust

Leaf rust kills organic coffee crops as well as regular coffee. The basic problem with coffee leaf rust is that when there is a big infestation the planter needs to remove all plants, treat the soil, and replant. This takes five years to produce a crop with new plants. In addition, if the planter simply chooses to use effective fungicides he loses his organic coffee certification for three years or more. The cost issues are such that leaf rust not only threatens coffee growers in general but also threatens to drive organic producers out of their niche. Is coffee leaf rust due to climate change? This is not an issue for the small grower. Finding rust resistant strains, treating outbreaks, and making a profit to support the family are the important issues.

Help Is on the Way

In the coffee producing nation of Colombia, the workers at the Cenicafé have found a cure for la rolla. Cenicafé is a research organization funded by the Colombian Coffee Growers Federation – the folks who bring you Juan Valdez coffee . In the early 1970’s coffee leaf rust was found in the Americas. In the early 1980’s Cenicafé started work on producing a Colombian leaf rust resistant coffee.

The Colombian leaf rust resistant coffee comes in two varieties, Colombian and Castillo. The first is a cross between an old Colombian variety, Caturra, and a rust-resistant strain from Southeast Asia, the Timor hybrid. Castillo is an offshoot of further cross breeding of the first Colombian leaf rust resistant coffee strain. Replanting with Colombian leaf rust resistant coffee in Colombia has reduced the incidence of leaf rust from 40% to 5% from 2011 to 2013.

Is coffee leaf rust due to climate change? Although the fungus does better at warmer temperatures it has been around for a century and a half. It is always there and ready to grow and devastate crops with conditions warrant. Replanting with rust resistant strains throughout the Americas will probably be the solution to this devastating disease.

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