Effects of shade trees on Coffea Arabica pests and diseases

Abstract

The coffee tree is a shade tolerant plant originating from Africa. Its cultivation however developed mainly apart from its zone of origin, particularly in Latin America, with intensive systems in full sun. With the extension of the zones of cultivation, certain traditional pests and diseases of the coffee tree, such as the coffee berry borer, also colonized new territories while others, such as the agent of the coffee berry disease Colletotrichum kahawae, remained on the continent of origin. During the extension of its zone of cultivation, the coffee tree encountered other pests and diseases which were already adapted to the new zones. The cultivation in full sun facilitates high production but requires more inputs, particularly pesticides. Today, the association of the coffee tree with shade trees in agroforestry systems is being studied from the point of view of greater crop and environmental sustainability. This paper presents an overview of the impact of shade trees on several important pests and diseases of the coffee tree. Various mechanisms, such as the barrier effect or the microclimate modification, will be discussed using examples. Lastly, recommendations will be proposed according to the pest and disease existing in the cultivation zones. The use of shade trees is particularly recommended in zones where the coffee berry disease prevails and agroforestry systems are especially recommended for use in these areas. © 2007 John Libbey Eurotext.