Ecophysiological constraints on the production of shaded and unshaded coffee: a review

The ecophysiological constraints on the production of the arabica and robusta coffee under shading or full sunlight are reviewed. These two species, which account for almost all the world's production, were originally considered shade-obligatory, although unshaded plantations may out-yield shaded ones. As a rule, the benefits of shading increase as the environment becomes less favorable for coffee cultivation. Biennial production and branch die-back, which are strongly decreased under shading, are discussed. The relationships between gas exchange performance and key environmental factors are emphasized. Ecophysiological aspects of high density plantings are also examined. (C) 2003 Elsevier B.V. All rights reserved.