Abstract Vegetative propagation through grafting remains central to cacao ( Theobroma cacao L.) improvement, ensuring genetic fidelity, uniformity, and accelerated productivity. Yet, the determinants of graft success—particularly the optimal segmentation of budwood—remain poorly defined. This study evaluated the effects of scion partitioning (entire, tip, middle, basal) across six National Seed Industry Council (NSIC)-registered clones or cultivars (BR25, PBC123, UF18, K2, K9, K1) under nursery conditions using a 4 × 6 factorial RCBD. Results revealed that significant interaction between scion segment and clone was not detected for graft success, leaf development, or stem girth. The entire scions achieved the highest grafting success (88.88%), statistically comparable to tip segments (85.00%), while middle (80.00%) and basal (78.89%) segments performed less favorably. Foliar initiation at 28 days post-grafting (DPG) was most rapid in entire and tip scions, though by 90 DPG leaf counts did not vary across all segments. Clone type significantly impacted stem diameter. While ‘K2’ outperformed ‘K9’ and ‘K1’ in radial expansion, its growth was comparable to ‘UF18’, ‘BR25’, and ‘PBC123’. Collectively, these findings provide insight into graft union development and practical guidance for optimizing propagation protocols. By validating the compatibility of elite clones with ‘UF18’ rootstocks and demonstrating the viability of scion partitioning, this work strengthens nursery capacity to deliver high-quality planting materials essential for the sustainable expansion of cacao plantations.
Vences C. Valleser (Fri,) studied this question.