The World Cocoa Foundation (formerly the American Cocoa Research Institute has had long relationship with the CRU, starting in the 1960's with their invaluable support of W.S. Chalmers' collection expeditions.   More recently (from 1993-1998), an evaluation of cocoa butterfat content of 450 accessions of the ICG, T was undertaken with funding from the WCF when it was known as ACRI.

Details of the current research project financed by WCF are summarised here. CRU staff members involved in the project are also listed and they may be contacted directly with any questions or comments.

Evaluation of cacao germplasm for resistance to Witches' Broom disease

Witches' Broom (WB) disease, caused by Crinipellis perniciosa, is one of the major diseases faced by cocoa producers in Latin America. The disease is endemic to the forests of the Amazon basin and it has long been known in the Upper Amazon regions of Brazil, with pod losses in this region reaching 95% on occasions. Witches' Broom disease was first observed in Trinidad in 1927 and the search for resistance to Witches' Broom disease began in the 1930s at the Imperial College of Tropical Agriculture (now the University of the West Indies). Since that time, research into cacao and cacao diseases in Trinidad has continued uninterrupted to the present day. In the 1980's, various collections of cacao germplasm previously brought into Trinidad were re-established on a single site to form the International Cocoa Genebank, Trinidad (ICG, T). Almost half of these accessions had been selected for the lack of of WB symptoms on the parent tree in the area where they were found.

Detailed information is required on the level of resistance to WB in accessions at the ICG, T, with a view to selecting parents for germplasm enhancement. In order to acquire this information, a project for the mass screening of cacao germplasm is in progress.

Phase I of this project took place from July, 1998 to July, 2003. Phase II began in August, 2003 A spray inoculation method is being used, based on an automated belt spray system developed by Purdy et al.., (1997), which was designed for inoculation of large numbers of seedlings. We have adapted the system to screen grafted clones rather than seedlings. The plant material to be screened is collected from the ICG,T as budwood and top-grafted onto TSH rootstocks, and then kept for three months to allow the grafts to become established.
During Phase I of the project we screened over 700 accessions from the ICG,T.

Project Staff

Penina Deberdt (until March, 2008)
Annelle Holder-John
Romina Umaharan
Surendra S.-Maharaj (until June, 2008)