Effects of Seed Treatment on the Germination of Crotalaria verrucosa L.

The study was conducted to ascertain the type of dormancy and evaluate various methods for breaking the dormancy of Crotalaria verrucosa L. seeds. The seed coat anatomy was also carried out to determine the relationship between the seed coat and the nature of dormancy. The seeds were subjected to the following treatments: immersed in 50%, 70% and 100% sulphuric acid (H2SO4) and hydrochloric acid (HCl) for 2, 5, 10, 15, 20 and 30 minutes respectively, soaked for 24 hours in 10 mM, 50 mM, 100 mM, 1000 mM sodium nitrate (NaNO3) and soaked in hot distilled water (50°C, 70°C and 100°C) for 2, 5, 10, 15 and 20 minutes. The treatments were replicated four times. Germination increased significantly after treatment with concentrated H2SO4 for 20 minutes (87.5%), concentrated HCl for 30 minutes (47.5%), 100°C distilled water for 20 minutes (72.5%) and 50 mM NaNO3 (62.5%). All the treatments increased the germination of C. verrucosa seeds significantly at P=.05 when compared with the control (12.5%). However, treatment with concentrated H2SO4 for 20 minutes was most efficient in promoting germination (87.5%). Anatomical analysis of the seed coat revealed several layers of water and gas impermeable sclerenchymatous tissues (macroslereids, osteosclereids and cuticule). From the result obtained, the type of dormancy exhibited was found to be physical or exogenous in nature.