Effect of pre-sowing treatments on the germination of five legume species and their tolerance to desiccation

Two Experiments were conducted to understand the suitable pre-treatment methods to know the germination behaviour of five selected legume species (Albizia thompsonii, Calopogonium mucunoides, Crotalaria micans, Tephrosia candida, Albizia procera) and their desiccation tolerance. Pre-treatments given were control (no treatment), mechanical scarification (seed coat cutting), H₂SO₄ (97%) for different durations (30 sec, 5 min, 15 min and 30 min) and heat scarification 60°C (9, 19 and 24 hours) and 80°C (4, 19 and 24 hours). Out of the 11 pre-treatments tested, conc. H₂SO₄ and mechanical scarification provided significant results in all the five species. Mechanical scarification provided maximum germination (96.25%) of C. micans while, conc. H₂SO₄ treatment for 30 min provided maximum germination of T. candida (97.50%). Seeds of all species were dried down to the target moisture contents (TMC) of 9, 7, 5, 3 and 2.5 per cent using silica gel for the second experiment to study the effect of seed desiccation on viability of these seeds. The viability of C. mucunoides reduced to 80 per cent at 3 per cent TMC while for T. candida, it was 75 per cent at 5 per cent TMC. In addition, the viability of both the species reduced greatly when dried below 3 per cent TMC. Both species i.e. C. mucunoides and T. candida took 37 days to reach the set TMC of 2.5 per cent using silica gel drying.