Comparative Evaluation of the Influence of Organic and Inorganic Fertilizers on Growth Performance of Tetrapleura tetraptera

The continuous destruction of our rainforest has threatened the existence of many useful and multipurpose plant species such as Tetrapleura tetraptera. To revert this situation, efforts must be made towards its sustainable use by encouraging reforestation which entails raising of seedlings for mass propagation of this crop. This study was aimed at comparing the effects of organic (chicken litter) and inorganic (NPK 15:15:15) fertilizers on seedling growth in four accessions of Tetrapleura tetraptera and hence determining fertilizer preference for this forest species. The Complete Randomized Design (CRD) was used in a factorial arrangement with four accessions and three fertilizer types in eight replicates. One month after transplanting, the fertilizers (organic and inorganic) were uniformly applied at the rate of 45 kg/hectare according to the experimental design. Data were collected monthly for a period of three months on plant height, stem diameter, leaf area, leaf length, member of branches, number of leaves, primary and secondary internode length per plant. Data on seedling emergence were also taken. Data collected were subjected to a two-way analysis of variance. Least significant difference (LSD) was used to separate significant means at p = 0.05. Result obtained revealed that the soil was rich in calcium, phosphorus and organic matter but low in nitrogen and potassium which were adequately complemented in mean days to seedling emergence in four accessions studied. Our findings also revealed that the organic (chicken litter) fertilizer did better (P<0.05) in all accessions than inorganic (NPK 15:15:15) fertilizer for all morphological traits studied. The performance of Cross River accession was outstanding as illustrated by the significant interaction obtained in most parameters. With chicken, litter fertilizer, Cross River accession produced the tallest plant (27.38 cm), largest leaf area (1.99 cm2), highest number of branches (20.13), highest number of leaves (66.75), longest stem diameter (0.93 cm), longest leaf length (1.94 cm), lowest primary (0.80) and lowest secondary (0.83) internode length. The use of organic fertilizers is therefore recommended for improved seedling growth of Tetrapleura tetraptera.