Propagation of Pentaclethra macrophylla Benth (Fabaceae) through seed and rooting of leafy stem cuttings

Abstract We assessed a number of factors controlling seed germination and rooting success of leafy stem cuttings of a high priority fruit (food and medicine) tree species from West and Central Africa, i.e. Pentaclethra macrophylla Benth (Fabaceae). In the case of seed germination, we tested three substrates (soil, sand, and a mixture of soil + sand (2:1)), mechanical seed scarification and seed position in the pod (proximal, median and distal), while for leafy stem cuttings, the two factors tested were substrate (sawdust, river sand and the mixture of sawdust + river sand (1:1)), seradix-2 (an auxin used for rooting stimulation, compared to a control) and type of auxin (naphthalene acetic acid (NAA), indol butyric acid (IBA) and indol acetic acid (IAA)). The study was conducted in Yaoundé, Cameroon in 2011. Data analysis shows that there was no significant difference between germination substrates (P = 0.445). Meanwhile, mechanical scarification significantly increased germination percentage (P = 0.04), whereas seed position induced significantly higher germination rates with the median position (100%, P > 0.001). Concerning leafy stem cuttings, the study showed sawdust to be the best rooting medium followed by river sand and mixture. Rooting percentages were at 60.26 ± 6.22%, 32.22 ± 6.04% and 25.27 ± 5.67%, respectively (P < 0.001). Seradix-2 and type of auxin had significant effects on rooting ability of leafy stem cuttings (P = 0.05 and P = 0.002, respectively). NAA and IBA were the best hormones. Our results show P. macrophylla is moderately amenable to rooting of leafy stem cuttings. Choosing seeds from median position in a pod can optimize germination percentage.