Cover photo: Jairo Cajina
By Dr. Francisco Anzueto Rodriguez, researcher with ANACAFE (National Coffe Association)
“La roya,” a fungus that attacks coffee plants, arrived in Central America in 1976 and caused relatively few losses during its first three decades in the region. But since 2010, it has become a severe and growing problem and recent climate variation is a principal factor.
In 2010, Guatemala saw sporadic roya attacks in several high-altitude regions. In 2011-2012, the attacks became more severe and caused substantial losses in coffee production at local levels.
In 2012-2013, the fungus spread throughout the southeast, northeast, north, central, and southern coast regions of Guatemala. In 2013-2014, the southeast and northeast were again affected, along with Huehuetenango in the northwest. Combined losses from 2012 to 2014 are estimated at 80,000,000 pounds of peeled coffee beans and 100,000 jobs. The climatic conditions of this period are similar to those projected for the future by some models that predict climate change. This means that similar behavior of la roya and other coffee plant diseases could continue well into the future.
The plantations most affected by the roya were those with less productive, older, less pruned coffee plants without synthetic fertilizers. These plants are common to small-scale producers, to whom less credit or financing, necessary to recover from the fungus, is available.
Certified organic coffee has been the sector most gravely affected by the outbreak, because organic producers cannot use synthetic chemicals like “systemic” fungicides. The “non-systemic,” or contact, fungicides that contain copper and are allowed in organic production have not been able to contain the spread of the fungus that has reached epidemic proportions. Before the outbreak, the average production quantity for organic coffee was 1,200 dried pounds per manzana (1.75 acres), which has now fallen to 600 pounds and even less. One strategy to confront la roya is to substitute traditional plants for more resistant ones, which requires large investments of capital and time without harvests.
An ANACAFË analysis of climate data shows that in 2010 and 2011 conditions were favorable to the roya, allowing it to subsequently spread through several regions at over 1,000 meters above sea level. In 2012, the outbreak reached a peak because of several factors: favorable climate conditions, the high proportion of plants with past damage, the predominance of susceptible coffee plant varieties (88% of the varieties used in Guatemala), and little technical management of fields.
There currently exists high prevalence of both damage from previous infections and climate conditions favorable to a new outbreak of la roya in 2015.
In 2012, minimum daily temperatures increased an average of 0.9°C while maximum daily temperatures fell 1.2°C, which implies a reduction of daily temperature fluctuations. This very probably caused la roya’s latency period to shrink and for its reproductive cycles to accelerate, which in turn led to more roya. In 2014, the outbreak continued with high prevalence of both fungus spores and damage in coffee plant leaves. Fungus sporulation increased, as did dispersion of the spores on infected coffee leaves.
There currently exists high prevalence of both damage from previous infections and climate conditions favorable to a new outbreak of la roya in 2015. This makes appropriate prevention and control measures with systemic fungicides and good technical management of coffee fields (fertilization, modifications, pruning, weeding, etc.) all the more important. (Editorial note: Entremundos does not endorse the use of non-organic methods.)
It will be necessary to adjust coffee-growing methods, and to expand the predominant shade-growing system that uses trees to shade coffee plants. This method enables a better adaptation to climate change so that Guatemala can continue to produce its coffee of world-renowned quality.