Effects of Seed Size on Germination and Early Morphorlogical and Physiological Characteristics of Gmelina Arborea, Roxb

A research was carried out to determine the effects of seed size ongermination and early growth rate of Gmelina arborea. Mature seeds ofGmelina arborea were collected from the mother trees in Uyo LocalGovernment Area, Akwa Ibom State. They were grouped into 3 categories as large seed size (LSS), medium seed size (MSS) and small seed size (SSS), using a predetermined weight method. A total of six hundred depulped seeds from each size class were selected and weighed and had the following values: 0.94g, 0.57g and 0.38g respectively. The seeds were sown in germination boxes measuring (28cm x 14cm x 14cm) and germination was observed for two weeks. Germination percentages were calculated by dividing the number of germinated seeds against the number of seeds sown. At two-leaf stage, seedlings were transplanted into polythene pots and laid out in a Randomized Complete Block Design (RCBD), replicated 3 times. Seedling height (cm), number of leaves, collar diameter (cm), leaf area (cm2) were assessed fortnightly while shoot dry weight (g/m) and root dry weight (g/m) were assessed monthly. Data collected were arc-sine transformed before being subjected to a two-way Analysis of Variance (ANOVA). Least Significant Difference (LSD) at 5% probability level was used to compare the significantly different treatment means. Biomass data were used to calculate Relative Growth Rate (RGR), Average Growth Rate (AGR) and Shoot Root Ratio (S/R) of the species. In all the parameters assessed, LSS had the best performance which was significantly different from other seed sizes. Thus, LSS are recommended to silviculturists and tree planters for best germination and seedling vigour