Conservation of cacao germplasm in the International Cocoa Genebank, Trinidad

Each cacao accession in the ICG,T is represented by up to 16 closely planted trees. This system is designed to quickly obtain a closed canopy that, once established, will withstand periods of low input with minimum risk to the genetic material. This design has proved to work well for accessions which are easy to establish from cuttings, but for those that are difficult to establish, gaps in the canopy make weed control a constant problem.

There is a need for shade management, particularly for newly planted cacao until it is established. Banana provides shade during the first few years, after which it is replaced by Erythrina spp. trees. Existing shade trees, conserved when the ICG,T was planted, are now old and are liable to fall and damage the cacao, so need to be replaced.

Trees propagated for use as windbreakers to protect cocoa germplasm in the International Cocoa Genebank, Trinidad. Image copyright Cocoa Research Centre

There is usually a marked dry season in Trinidad from January to June. During this period, irrigation is necessary to ensure the survival of recently established trees. It is particularly important to water rooted cuttings that lack the deep tap roots of seedlings. If accessions have proved difficult to establish from rooted cuttings, it may be necessary to conserve them by grafting their budwood onto rootstocks in a clonal garden. Once established, cuttings can be taken from this material and rooted to fill gaps in the ICG,T.

New introductions, difficulties of establishment, and filling gaps in the ICG,T mean that field maps and databases need to be continuously updated. Each tree is given a unique number to accurately record the source of material for research and other purposes, so that identified off-types can be recognised.


Other CRA Projects

Disease Screening | Characterisation | Verification | Germplasm Enhancement | Collection/Distribution