Ecological Mechanisms for Pest and Disease Control in Coffee and Cacao Agroecosystems of the Neotropics

Pests and diseases can have impacts upon most ecosystem services (ES), including food production and yield (Cheatham et al, 2009). Food production, according to the Millennium Ecosystem Assessment (MEA, 2005) is one of the most important ES. In severe cases, pest and disease damage results in plantation abandonment, famine and emigration. The Irish potato famine, caused by potato blight (Phytophthora infestans) in Ireland between 1846 and 1851, is one of the best-known cases. In the tropics, examples of disasters caused by pests include the coffee leaf rust (Hemileia vastatrix) in Ceylon (now Sri Lanka) during the 1870s, the coffee wilt disease (Gibberella xylarioides) in Central Africa during the 1940s and 1950s, and Fusarium oxysporum, the causal agent of Panama disease on bananas in Latin America during the 1960s. More recently, two closely related cacao pathogens, Moniliophthora perniciosa (previously Crinipellis perniciosa), the causal agent of witches’ broom, and Moniliophthora roreri, the causal agent of frosty pod rot, have wreaked havoc among cocoa producers in the Neotropics. After the arrival of witches’ broomin Bahia in 1989, Brazil moved from being the second largest cocoa producer in the world (374,000 tonnes in 1988) to the fifth rank in 2000, with a 47 per cent decrease in production despite a 6 per cent increase of the planted area during the same period (Meinhardt et al, 2008; FAO, 2010). Similarly, frosty pod rot led to the almost total disappearance of cacao cultivation in Costa Rica during the 1970s.