Effect of Rooting Media, Nitrogen and Phosphorus Fertilization on the Seedling Growth of Gmelina (Gmelina) and Teak (Tectona)

Abstract

The rising increase in the quest for wood materials necessitates the need to produce more within the shortest time. This can be achieved by increasing the seedling growth of the tree species either by improving the fertility level of the rooting medium or using the most suitable rooting medium, thus necessitating the study. This study was laid out in a completely randomized design with three replications. Treatments include rooting media levels (soil, sawdust, soil: sawdust 1:1, 1:2, 2:1) and poultry manure (0, 5, 10 t ha-1) for the first experiment while the second experiment involved varying rates of N fertilizers (0, 30, 60, 90, 120 kg ha-1) and P fertilizers (0, 45 and 90 kg ha-1). It involved two pot experiments carried out concurrently at the agro forestry arboretum of the Federal University of Agriculture, Abeokuta with each set transplanted to gmelina and tectona seedlings. Data were collected on plant height, stem girth and number of leaves fortnightly for 16 weeks. There was significant increase in height, stem girth and number of leaf gmelina at all weeks while tectona significantly increased only in height and stem girth using soil as a medium in comparison to other rooting media. N and P fertilizers produced no significant effect on the seedling growth of both tree seedlings. The use of N and P fertilizers on the seedling growth of the tree species was not encouraging as results obtained weeks after transplanting were not consistent. However, if there is a need for its use, 60 kg N ha-1 and 45 kg P ha-1 produced desirable seedling growth parameters. It is concluded that the use of soil and application of poultry manure at 5 t ha-1 remains the most effective rooting medium for gmelina and tectona seedlings.