Fruit and canopy pathogens of unknown potential risk

Abstract

The worldwide threat to cacao production from the major pests and diseases continues to overshadow other problems of local or sporadic importance. Since the introduction of cacao (Theobroma cacao, L.) from its center of diversity in the Amazon forest into other regions of the world, several diseases, often regarded as minor pests, affects production of the crop in various cacao-producing regions and countries. These diseases may not be globally important, but may have very great local impact on production wherever they are found. Among these minor diseases are pink diseases caused by Erythricium salmonicolor, charcoal pod rot, caused by Lasiodiplodia theobromae, warty pod, a disease of unknown etiology, mealy pod caused by Trachysphaera fructigena, thread blight caused by Marasmius species, brown root rot caused by Phellinus noxious, and anthracnose of cacao caused by Colletotrichum species. Most often, the symptoms of cacao pod diseases are similar, and this often confuses farmers and extension personnel, resulting in either the overestimation or underestimation of these diseases in the field. This chapter discusses the situation and outlook, taxonomy, distribution, symptoms, modes of spread, and impact of these diseases on cacao. It also discusses control measures available for these diseases and future prospects for their management.