Field assessment for resistance to Witches' Broom and Black Pod Diseases

Witches' Broom (WB) and Black Pod (BP) diseases are of great economic importance in cocoa producing countries. Worldwide, losses due to BP have been estimated at 20%.WB, however, only occurs in South America and some islands of the Caribbean where it is responsible for 20 to 50% of pod losses. In addition, this disease can also pose a serious problem in the establishment of new plantings.

Current control measures for these diseases, which include chemical and phytosanitary methods, have often proved to be unsatisfactory and very expensive. To compliment laboratory screening programmes for these diseases (using detached pod inoculations for Black Pod and a spray inoculations for Witches' Broom), field observations of disease incidence in the ICG,T are being made. About 230 accessions were observed each year between 1999 and 2001, choosing clones with interesting traits or those found resistant in laboratory screening trials.

Project Staff
Jean-Marc Thévenin
Romina Umaharan