Hemileia Vastatri, orange rust of the coffee tree

Dany Marquis

Hemileia Vastatri, orange rust of the coffee tree There is currently a phenomenon that concerns those in the coffee industry and is hurting coffee-producing communities in South America. Hemileia Vastatri, the orange rust of coffee , has already been a source of problems responsible for severe epidemics in Costa Rica in 1989, in Nicaragua in 1995 and in Colombia, from 2008 to 2011. But despite the damage caused, the strike that What producers experienced in 2012 was nothing comparable. Because it is a real epidemic that has been raging since 2012, especially in Central America. The disaster is estimated at a loss of nearly 20% of harvests and experts estimate that the phenomenon could last until 2016. The total economic losses linked to the 2012/13 epidemic amount to hundreds of millions of dollars with social implications that are difficult to estimate.

Caused by a fungus, rust , Hemileia vastatrix, attacks the leaves of the coffee tree and can cause severe defoliation, abnormal leaf fall. Its history is well known: in 1869 it devastated all the coffee growing in Ceylon (today Sri Lanka).

The year 2012 was a year of climate disruption linked to a warming of the Pacific Ocean. This phenomenon is called El Niño . ( El Niñ o less serious version ) . In Central America, this disturbance is mainly characterized by less rainfall. A series of factors would have triggered and worsened the phenomenon in 2012:

del Niño

·           Light rain which did not allow the spores of the fungus to be cleaned from the leaves of the coffee tree, which ensured their germination;

·           Higher average temperature during 2012 reduced the latency period of the disease and greatly increased its ferocity. It also favored attacks at high altitudes, the preferred location for the best arabicas, deemed unfavorable to the disease due to the lower temperatures. Growers generally do not apply treatments to prevent rust in these areas. They got caught and had to do late treatments which had more or less effect having been applied too late.

·           The wind. This spread the rust over great distances which caused a lot of trouble controlling the epidemic.

·           Place of culture. Planting location has a direct effect on rust development. The more the plantations are located in direct sunlight, the more they are affected. Plots located under shaded cover are less affected by rust. Shading seems to slow down the development of the fungus.

·           Evolution of the pathogen. More difficult to move forward for the moment but several experts are leaning towards this phenomenon rather than the conjuncture of direct climatic conditions. The weather would have influenced the fungus causing rust, making it more aggressive, more adapted to extreme climatic conditions. The continued application of fungicides may also have allowed the appearance of a new, more resistant strain.

Hemileia Vastatri, orange rust of the coffee tree It's a state of emergency. The International Coffee Organization (ICO) estimates the number of bags lost during the 2012/2013 campaign, currently underway, at 2.5 million. Losses could climb to 5 million bags, according to Ricardo Villanueva, president of the private sector advisory office at the ICO. He said Central America could take ten years to absorb the damage caused by the rust.

More than 350,000 coffee producers are affected in Central America, recalls the ICO, which adopted a resolution on March 8 according to which cooperation and assistance mechanisms must be deployed between its member countries.


Despite the consequences of this epidemic, production should increase by 4.75% between the 2011/2012 and 2012/2013 campaigns according to the American Department of Agriculture, to 151.2 million bags.

And this is probably why, despite this phenomenon, the price of coffee on the stock market has not flinched and has remained quite low since 2012.

The big loser from this phenomenon will surely be the producers of certified organic coffee. Producers wishing to respect the certification criteria will see their plantation attacked by the phenomenon of rust, which should increase losses and cause an increase in price.


For the moment, this phenomenon does not affect consumers, whether in terms of price or quality of exported coffees. We will see in the coming years how the coffee chain will react to this phenomenon.

To continue reading, I invite you to consult the following texts or to Google the subject:

Some Insights on Coffee Leaf Rust (Hemileia vastatrix) by Emma Bladyka, SCAA Coffee Science Manager/

Coffee rust by The American Phytopathological Society

Danny Marquis

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