Successful grafting elite cocoa clones (Theobroma cacao L.) as a function of the age of rootstock

Côte d'Ivoire, the world's largest cocoa producer, faces numerous challenges because the yield of orchards is low due to several factors including the non-use of improved plant materials. This work is part of ICRAF's Vision for Change (V4C) project, which aimed at contributing to the regeneration of cocoa farms by making effective plant materials available to small cocoa producers. It essentially consisted in evaluating the effect of the age of the rootstock on the success of grafting to obtain a satisfactory quantity of improved plants in the nursery. The study was carried out in Adiopodoumé at the National Agronomic Research Center (CNRA). Ten elite cocoa clones from the “Vision for Change” project were used as scions. Top grafting was performed on seedlings of 2, 3- and 4-months used as rootstocks. The experimental design was a randomized complete block design with 3 replications. Data collection was focused on the grafting success rate and morphological parameters. The results showed that the grafting success rate is proportional to the rootstock age. Two months after grafting, the success rate was low. This indicates that grafting should eventually start at 3 months. This period could therefore represent a good stage to successfully graft and replant cocoa seedlings.