Shade management in coffee and cacao plantations

Background

Shade trees reduce the stress of coffee (Coffea spp.) and cacao (Theobroma cacao) by ameliorating adverse climatic conditions and nutritional imbalances and increase the biodiversity of coffee farms, but they may also compete for growth resources. This review summarizes the literature on ecological aspects of shade-grown coffee and cacao and on management of shade trees, but does not address economic and social aspects of shade-grown coffee and cacao.

Research goals & methods

Shade trees buffer high and low temperature extremes by as much as 5 °C and can produce up to 14 Mg ha^–1 yr^–1 of litterfall and pruning residues, containing up to 340 kg N ha^-1 yr^-1. Separately from litterfall, N2 fixation by leguminous shade trees grown at a density of 100 to 300 trees ha may not exceed 60 kg N ha^-1 yr^-1. Shade tree selection and management are potentially important tools for integrated pest management because increased shade may increase the incidence of some commercially important pests and diseases and decrease the incidence of others.

Conclusions & takeaways

The relative importance and overall effect of the different interactions between shade trees and coffee/cacao are dependent upon site conditions, species/varietal selection, belowground and aboveground characteristics of the trees and crops, and management practices. On optimal sites, coffee can be grown without shade using high agrochemical inputs. However, economic evaluations, which include off-site impacts such as ground water contamination, are needed to judge the desirability of this approach. Standard silvicultural practices need to be adapted for open-grown trees within coffee/cacao plantations.