Evaluation of Different Pre-Treatments on Seed Germination of Some Cassia Linn. spp.

Abstract

Seed dormancy limits the uniform propagation of several Cassia species because of the presence of a hard, water-impermeable seed coat. This study evaluated the effects of thirteen pre-sowing treatments on seed germination percentage and mean daily germination (MDG) of Cassia fistula L., Cassia glauca Lam. and Cassia tora L. Seeds were collected from Samastipur district, Bihar, India, surface-sterilised and subjected to physical, chemical, hormonal and combined pre-treatments. The experiment was arranged in a completely randomised design with five replications, with 40 seeds per treatment for each species. Germination was recorded daily for 14 days under controlled laboratory conditions. Untreated seeds showed the lowest germination, with 17.5% in C. fistula and 20.0% in both C. glauca and C. tora. Among the treatments, soaking in sulphuric acid (H₂SO₄) at 550 ppm for 5 minutes, followed by gibberellic acid (GA₃) at 550 ppm for 24 hours, gave the highest germination and MDG in all three species. This treatment produced 82.5% germination in C. fistula, 85.0% in C. glauca and 90.0% in C. tora, with corresponding MDG values of 5.89, 6.07 and 6.43. Mechanical scarification followed by GA₃ also improved germination, although it was slightly less effective. The findings indicate that combined scarification and GA₃ treatment can improve laboratory germination of the tested Cassia species.