Root Segment Cuttings of Bombax costatum Pellegr. & Vuillet: Effects of Diameter and Alignment

Bombax costatum is a very important agroforestry species in the Guinean savannahs highland of Adamawa. The objective of this work is to contribute to the domestication of this species by cuttings of root segment. The cuttings of root segment of this species were carried out according to a split-plot design with three replications. The diameter range of cuttings used (0.5-1.1 cm; 1.2-2 cm and 2.1-3.8 cm) and the alignment of the cuttings (vertical, horizontal and oblique) in the substrate consisting of sand/sawdust represented the main treatment and the secondary treatment respectively. The experimental unit was 10 cuttings. The result showed that cuttings with large diameters between 2.1 and 3.8 cm (62.22±1.75%) are the best for budding. The diameter significantly influences the budding of the cuttings (0.0004 < 0.001). Regarding the alignment of the cuttings in the substrate, the maximum budding (52.22±2.01%) is obtained in those placed in an oblique alignment. However, this alignment did not significantly influence the budding of root segment cuttings (0.33 > 0.05). Regarding the rooting of cuttings, a high rate (28.88±1.36%) is observed in cuttings whose diameter class is between 2.1 and 3.8 cm. The diameter range significantly influences rooting (0.002 < 0.01). The alignment of the cuttings in the substrate did not significantly impact the rooting of the cuttings (0.90 > 0.05). These results show that vegetative propagation of Bombax costatum from root segment cuttings is possible. This is an important step for the domestication of this species.