Contribution to the Domestication of Beilschmiedia mannii in Côte d'Ivoire: Effect of Cutting Size and Indole-3-Butyric Acid (IBA) on Rooting and Growth

Beilschmiedia mannii, or spicy cedar, is a tree species of significant food and medicinal value that naturally grows in the tropical forests of Côte d'Ivoire. Unfortunately, severe deforestation and climate change pose a serious threat to the survival of this species, raising concerns about its conservation status. This study aims to develop methods for propagating Beilschmiedia mannii plants through the cutting technique. For this, three categories of cutting (small, medium, and large diameter) were treated with three concentrations (0, 2.5, and 5 mg/L) of Indole-3-Butyric Acid (IBA) and planted in a polypropagator on forest topsoil mixed with construction sand. Once rooted, the cuttings were transplanted into black polyethene bags. As a result, the 100% survival rate observed after plant acclimatisation demonstrates the strong propagation capacity of Beilschmiedia mannii through cutting. The cuttings of small- and medium-diameter exhibited good rooting ability, unlike those with a large-diameter. The 5 mg/L IBA concentration produced the highest rooting success with 36% for small and 53% for medium cuttings, and resulted in the greatest number and length of roots per cutting. The best vegetative growth was observed in plants grown from medium- and small-diameter cuttings treated with 5 mg/L and 2.5 mg/L of IBA, respectively. These findings demonstrate that combinations of IBA and cutting propagation is an effective method for producing uniform, vigorous and healthy seedlings of Beilschmiedia mannii intended for integration into agroforestry systems and sustainable reforestation programs.