Effects of three pretreatments on seed germination and seedling growth of Mansonia altissima (A. Chev.) in a nursery, a timber species exploited in Cote d'Ivoire

Côte d'Ivoire's forests are a reservoir of biodiversity. Indeed, they offer a diverse ecosystem service. However, they are subject to strong anthropogenic pressures, which have resulted in the disappearance of several plant species. This was the case of Mansonia altissima, a species renowned for the quality of its wood. Given the importance of this species, there is an urgent need to focus on its conservation. It is in this context that this study aims to improve seed multiplication and the growth of M. altissima seedlings with a view to using them in reforestation. To achieve this, three pretreatments were applied to the seeds. These were the control (T0), shelled and unsoaked winged fruit (T1) and winged fruit soaked in cold water for 48 hours and then shelled (T2). Data collected using a data collection form were subjected to statistical analysis. Results showed that T2 treatment recorded the best germination rate (83%). In terms of seedling growth, the pretreatments had a significant effect on seedling diameter (P > 0.05). As for height, which averaged around 8 cm, and number of leaves, which averaged 6 per individual for each pretreatment, no significant effect was observed. However, for a multiplication of the species, the pretreatment (T2) where the winged fruits are soaked in ordinary water for 48 h and then shelled is recommended.