Effects of Cold Water, Mechanical and Acid Scarifications on Germination and Seedling Growth of Pre-Chilled Seeds of Leucaena leucocephala

The effects of pre-chilling on seed germination and seedling growth of Leucaena leucocephala were examined, alone and combined with soaking in cold water, clipping and immersing in concentrated sulfuric acid. Results showed that germination percentage of freshly harvested seeds was improved significantly by pre-chilling. Germination percentages of pre-chilled seeds soaked in cold water in the short duration were significantly lower than control, but their radicle length and seedling vigor index were higher. Sandpapering in conjunction with pre-chilling is the most efficient methods for high germination percentage, germination time and seedling growth index. Immersion of seeds in sulfuric until 20 minutes period had no significant effect on germination percentage, but it significantly reduced radicle length, hypocotyls length and seedling vigor index. These results confirm the earlier findings that seed dormancy in Leucaena leucocephala to be external and internal type.