Résumé
Creation and dissemination of Arabica coffee varieties: What varietal innovations?
Over 80 % of all Coffea arabica - a species of African origin - is produced in Latin America. The gene pool of C. arabica, which was introduced in Latin America in the 19th century, includes only two relatively similar varieties (Bourbon and Typica). Despite this very weak gene pool, researchers have managed to develop pure line varieties that are very well adapted to crop intensification (1950-1980) and that produce coffee of recognised standard quality. With the advent of coffee rust, resistance genes of the diploid species C. canephora were transferred to these improved C. arabica varieties. Lines combining resistance to several diseases, and having a cup quality equivalent to or less than standard, were developed (1980-2000). As of 1990, to fulfill market requirements, new hybrid F1 varieties were bred to be adapted to agroforestry-based ecologically intensive cropping systems. After some 20 years of testing in controlled environments or on coffee farms, F1 hybrids were found to produce 30-60 % more than the best lines grown in agroforestry systems. This performance is achieved without any supplementary fertilizer input. Little of the genetic progress is currently disseminated to growers. In many countries, varieties are propagated without any control of their varietal purity. There are no existing catalogues and information that does reach growers is not sufficient to help them make varietal choices according to their cropping systems or market requirements. Generally, for such an economically important crop, there is a strikingly low degree of research and investment in coffee improvement simply because improved seed production is not profitable for private stakeholders. In areas where the State has withdrawn, the private sector should be given the opportunity of investing in quality seed production and research.