Factors affecting Pterocarpus erinaceus Poir. seed germination and seedlings growth in the Republic of Benin

Abstract

African rosewood (Pterocarpus erinaceus Poir.) is a multi-purpose woody species threatened by an insufficient natural regeneration in the wild. Seed pre-treatments are expected to improve seed germination, but their effect may vary according to seeds provenance. In the present study, differences in seed germination capacity and seedling growth among three provenances of pre-treated seeds of P. erinaceus were evaluated. Seeds were collected in the three biogeographical zones of Benin. Two seed treatments were tested: treatment 1, seed left in cool water (15°C) for 24 hours; treatment 2, scarified seed; and seed with no treatment (control). The treatments and provenances were combined in a randomized complete block design with three replicates. The germination dynamics, seedling growth in diameter, total height and number of leaves as well as parasitic pressure (the number of attack) of seedlings were analysed using linear mixed effects model. The highest germination rate was recorded for seeds from the Sudanian zone, up to 45% on day 39 resulting to the adaptability of this species to new environment. There was a significant (Prob < 0.05) effect of seed pre-treatment on diameter growth, seedling height and number of leaves. High parasitic pressure was observed on seedlings and further researches are needed for controlling parasite. Based on these observations Sudanian seeds must be proposed and strategies are required for the efficient ex situ conservation of P. erinaceus.

Keywords:  P. erinaceus, seeds provenances, pre-treatment, germination capacity, seedling growth