Variation of leaf and fruit characteristics of Vitellaria paradoxa (shea tree) according to agronomical performance along south-north climatic gradient in Mali

Abstract

Shea trees identified for agronomical performances were compared through leaf and fruit characteristics. Seventy adult trees were selected using purposive sampling from seven sites along a south-north climatic gradient covering four agro-climatic zones. The effects of two factors (type of performance and site) on leaf and fruit parameters were investigated. Results showed significant effect of the type of the performance as shea trees performant for pulp production had longer petiole and laminar, wider laminar basis and top and had longer, wider and heavier fruits with more abundant pulp as compared to those performant for butter production. The factor site was found significant for all leaf and fruits parameters but the effect of climatic gradient was rare. The leaves in Siby and Kaniko had the longest laminar and the widest laminar basis, but those in Kaniko and Noumoudama had the widest laminar as compared to all other sites. The leaves in Noumoudama had the shortest petiole as compared to the rest. The leaves in Nampossela, Zanzoni, Solosso and Noumoudama had the widest laminar top as compared to those of Kaniko, Siby and Fougatiè. The longest fruits were observed at Nampossela, while the widest and heaviest fruits as well as the most abundant pulp were observed at Kaniko and the heaviest nuts were observed at Siby. The smallest and slightest fruits were observed at Noumoudama and Solosso in more arid zones, but often, not significantly different from some sites in wettest zones regarding certain fruit parameters. This study highlighted phenotypic descriptors of agronomical performance through the leaves and the fruits of this tree species.