Substrate and genotype effects on kola (Cola nitida [Vent.] Schott and Endlicher.) tree cuttings growth in nursery

Abstract

The kola tree (Cola nitida) belongs to family Malvaceae grown mainly for its seed. It is highly prized for its socio-cultural and industrial uses. However, there is a significant high variability due to a high proportion of allogamy in the reproduction mode. The influence of substrate and genotype on kola tree cuttings has been studied in order to propagate it vegetatively. Six growing substrates: 100% Black soil, 50% Black soil + 50% Wood sawdust, 100% Wood sawdust, 50% Soil + 50% Black-Coco, 100% Black-Coco, 50% Wood sawdust + 50% Black-Coco were tested on genotypes 305 and D9L7A1 using a split-plot experimental design with genotype as main factor and substrate as subplot treatment replicated three times. The experimental unit constituted 20 cuttings. Six months after transplanting, the average success rate of tunnel cutting from the kola tree to the nursery was 76.2±7.6%. The best success rates were obtained with 100% Wood sawdust, 100% Black soil and 50% Black coco + 50% Wood sawdust substrates with 85±4.5, 80.8±6.6 and 79.7±5.8%, respectively, regardless of the plant material used. The substrates 100% Black soil and 100% Wood sawdust gave the best results on growth parameters such as aerial dry biomass, height growth, roots number and new formed leaves. It also showed that genotype D9L7A1 had a higher vegetative leaves and roots development than genotype 305. These genotypes were well suited for cutting.