Abstract

Tree species are fast disappearing from the forest due to over exploitation without adequate regeneration which makes some of these tree species going to extinction, there is little information about breaking dormancy of Picralima nitida. This study was conducted to examine the effects of various dormancy breaking treatments under different conditions of tap water for 24 hours, hot water treatment 30 seconds, acid scarification, (H₂SO₄, HNO₃ and HCl for 30 seconds, 1 minute and 2 minutes respectively).The experiment was laid out in a Completely Randomized Design (CRD) with 12 treatments and replicated four times, A total number of one thousand three hundred (1300) seeds were used for this experiment, Germination count was observed for a period of 8weeks.and data generated was subjected to analysis of variance while LSD used to separate the means. The results of the effect of pre – sowing treatment on P. nitida showed the total germination was between 5% and 95% seeds. Seeds treated with H₂SO₄ (30% diluted acids) for 2 minutes produced the highest germination percentage (PG) of 95% while those treated with HNO₃ (30% diluted acids) for 30 seconds had 68%., followed by seeds treated with H₂SO₄ (30% diluted acids) for 1 minute had 59%. While control (without treatment had the least 5%) However, pre-sowing treatments had significant effects on germination of P. nitida seeds. In conclusion, this work has established an effective approach for breaking seed dormancy and enhancing seed germination of Picralima nitida and recommends the use of sulphuric acid for breaking dormancy of P. nitida seed and the time for soaking the seed in sulphuric acid should be 2 minutes in other to promote the germination process and improve the early germination of seedlings in the nursery.

Key Words: Picralima nitida, Seed, Dormancy, Germination and Acid scarification