STATUS OF CACAO WITCHES' BROOM: biology, epidemiology, and management.

Origins of Theobroma cacao and Crinipellis perniciosa occurred in the Amazon Basin region of South America, and their interaction, the witches' broom disease, was first described in the late 1700s. The 100 years of scientific investigations of witches' broom of cacao that began in the 1890s developed the present state of knowledge of the biology and epidemiology of witches' broom that are discussed. Recommended management to reduce the deleterious effects of witches' broom on cacao production include the use of phytosanitation (removal of diseased plant parts), applications of chemical fungicides, and the use of host resistance. At present, there is a paucity of resistant planting materials, and efforts to evaluate germplasm for resistance to witches' broom are described. Research topics to augment present knowledge about witches' broom of cacao are presented with the hope that disease management can be improved.