Vegetative propagation of cocoa (Theobroma cacao) by grafting: Aptitude of grafting on four clones

Abstract

The objective of this study is to evaluate the effect of hormones and fertilizers on the aptitude of grafting of four types of clones used in the seed fields for the creation, the regeneration, and the production of pods. The experimental design is a factorial trial (4 × 3 × 2 × 2) with hormone as the main block and other factors completely randomized within the blocks with three replicates. The aptitude of cocoa clones for grafting was assessed from 4320 grafted plants by recording survival rates, budding rates and number of leaves on a weekly basis from the 28th day after application of the hormones. Evaluation results indicated that there is a significant impact of clones, fertilizers, and grafting types on both the survival rate and growth parameters. Notably, the Trinitario ICS40 clone exhibited superior performance with an impressive 82.6% survival rate, a budding rate of 59.3%, and a total leaf count of 404. The different hormones did not have a significant impact on the measured parameters, whereas YaraMilla™ fertilizer demonstrated superior performance in enhancing the growth of grafted plants. Interestingly, side grafting displayed the highest survival rates (83.3, 69.4, 52.7 and 46.9% at 4 weeks, respectively) as well as a budding rate of 56%. However, it did not result in the highest number of leaves. This study represents the first report of grafting cocoa clones at the SODECAO experimental farm, and these findings open up possibilities for the propagation of disease-resistant clones.