Résumé
Coffee is one of the world’s most valuable export commodities, ranking second on the world market after petroleum products. The total retail sales value exceeded US $70 billion in 2003 and about 125 million people depend on coffee for their livelihoods in Latin America, Africa, and Asia (Osorio 2002). Commercial production relies on two species, Coffea arabica L. and C. canephora Pierre. The cup quality (low caffeine content and fine aroma) of C. arabica makes it by far the most important species, representing 70% of the world production.