Reproductive Phenology and Morphometric Variability of the Fruits and Seeds of Parkia biglobosa (Jacq.) R. Br. Ex G. Don According to Provenance Areas in Côte d’Ivoire

Background: Non-timber forest products (NTFPs), such as African locust bean (Parkia biglobosa), are strategic resources for food security in sub-Saharan Africa. However, the degradation of parklands and insufficient natural regeneration threaten the sustainability of this resource. Aims: This study assessed the influence of agroecological factors on reproductive phenology and fruit yield potential of P. biglobosa in Côte d’Ivoire. Methodology: Phenological monitoring was carried out on 10 individuals in Korhogo over a two-year period, corresponding to two phenological cycles of the species. Concurrently, ten trees of the species in each area of origin (Tiébissou, Niakara and Korhogo) were identified, and five fruit clusters were harvested from each for morphometric analysis. The data were subjected to statistical tests and multivariate analyses, including principal component analysis (PCA) and hierarchical cluster analysis (HCA). Results: The phenological cycle in Korhogo was relatively stable (123.67 ± 5.11 days; CV = 0.04), although morphological maturity exhibited substantial inter-individual variability (CV = 0.24). Morphometric analysis revealed significant differences among the study areas (p < 0.05). Tiébissou, located within the bimodal pre-forest zone, was characterised by heavier fruits (18.44 ± 4.11 g), greater pulp mass (6.60 ± 2.15 g), and heavier seeds (6.26 ± 1.64 g). PCA and HCA grouped the accessions into three distinct classes, with Class 2 (Tiébissou) comprising individuals exhibiting superior agronomic performance. Strong positive correlations were observed between fruit mass and pulp mass (r = 0.898) and between fruit mass and pulp-coated seed weight (r = 0.992). Conclusion: These findings indicate that agro-ecological gradients strongly influence the productivity of African locust bean. The Tiébissou morphotype represents a promising scientific basis for future breeding, conservation, and participatory domestication programmes for the species.