Influence of pre-germination treatments and seed source on germination and early growth of <i>Dialium guineense</i> (Willd)

Abstract

The study aimed at identifying the best pre-germination treatment that would produce fast and more uniform germination of Dialium guineense seeds obtained from different sources. Seeds obtained from Benin, Awka and Ore in Southern Nigeria were subjected to different pre-germination treatments, namely: Sulphuric acid for 10 minutes, soaking in hot water at 100°C until it cooled, overnight soaking in tepid water and control (untreated). The results revealed that seeds treated with sulphuric acid produced the highest germination rates of 82, 68 and 52% for seeds from Benin, Awka and Ore, respectively, while hot water treatment produced 15, 20 and 28% germination in same order. Overnight soaking in tepid water gave 15, 16 and 17% germination while control (untreated) gave 13, 12 and 10% for seeds from Benin, Awka and Ore, respectively. Seeds treated with sulphuric acid had mean seedling height of 12.30cm, 12.66cm and 12.00cm with mean collar diameter of 1.10cm, 0.91cm and 1.15cm and leaf number of 7, 7 and 7 for Benin, Awka and Ore respectively. Seeds treated with hot water produced mean seedling height value of 11.20cm, 10.90cm and 11.50cm with mean collar diameters of 0.87cm, 0.95cm, 0.94cm. Mean leaf numbers were 4, 6, and 6 for Benin, Awka and Ore seeds, respectively. Seeds soaked in water overnight had mean seedling heights of 11.80cm, 11.10cm and 11.80cm; collar diameter of 0.91cm, 0.95cn and 0.99cm; leaf number of 5, 7 and 6 for seeds from Benin, Awka and Ore, respectively. Control treatment had mean seedling heights of 9.30cm, 10cm and 10.06cm; collar diameter of 0.93cm, 0.90cm, and 0.95cm; leaf number of 5, 5, and 6 for Benin, Awka and Ore seeds, respectively. Source did not significantly affect the germination potential of the seeds but early growth responses significantly varied with source and treatments. Sulphuric acid has been recommended for large scale planters of Dialium guineense while hot water and overnight soaking in tepid water have been recommended for small scale planters. Further researches are needed in the area of early growth rate improvement of the species.