Shade management in coffee and cacao plantations

Abstract

Shade trees reduce the stress of coffee (Coffea spp.) and cacao (Theobroma cacao) by ameliorating adverse climatic conditions and nutritional imbalances, but they may also compete for growth resources. For example, 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. However, N2 fixation by leguminous shade trees grown at a density of 100 to 300 trees ha−1 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 (such as Phythphora palmivora and Mycena citricolor) and decrease the incidence of others (such as Colletotrichum gloeosporioides and Cercospora coffeicola). In Central America, merchantable timber production from commercially important shade tree species, such as Cordia alliodora, is in the range of 4−6 m3 ha−1 yr−1.