Tree size partially mediates the influence of climate on fruit and seed production in Ricinodendron heudelotii (Baill.) Heckel

Abstract

Understanding environmental drivers of fruit and seed production in wild edible fruit species is essential for their valorisation. Ricinodendron heudelotii is an oilseed plant whose kernels are particularly treasured in cosmetic and medical industries. This study assessed fruits and seeds production patterns of R. heudelotii. Data were collected for three consecutive years on 30 trees in the phytodistricts of Plateau, Pobè and South Borgou where it naturally occurs. Tree dbh, total height, crown diameter, number of fruits and seed mass were measured. Climatic data were obtained from NASA Power Database. Data were analysed using linear (seed mass) and generalised linear (number of fruits) mixed models and structural equation modelling. Fruit and seed production were significantly higher in the South-Borgou phytodistrict (1433 ± 1144 fruits, 4.26 ± 3.39 kg of Dry matter per tree) and Plateau phytodistrict (1.66 ± 0.35 g DM/seed). Tree dbh further significantly mediated the effect of minimum temperature, and relative humidity on seed mass. Tree dbh, irradiance and dry season rainfall were identified as the best-predictors of seed mass production (kg DM). These results improved current knowledge of the fruit and seed production of R. heudelotii and are of significant importance for the exploitation of the species.