Germination performance of different forage grass species at different salinity (NaCl) concentrations

Abstract

Certain grasses show potential for the rehabilitation of coalmine spoils. Species selection and evaluation are used to guide the choice of the most appropriate grass species. This study evaluated the germination performance of seven forage grass species, with some represented by two varieties, under varying salinity conditions of 0 (distilled H₂O), 100, 200, 400, 600, 800 and 1 000 mS m⁻¹ of NaCl. Cumulative germination, final germination percentage (FG%), and time taken to reach 50% of the final germination (T₅₀) were determined for each species–treatment combination. Species × salinity interaction was significant (p < 0.01) for cumulative germination, FG% and T₅₀. Cumulative germination increased gradually up to 17 days and thereafter declined. The highest FG% for all grass species was attained under distilled water (0 mS m⁻¹), ranging from 38% to 94%, and declined significantly (p < 0.01) with an increase in salinity. T₅₀ increased with increasing salinity for all grass species. Eragrostis curvula var. Ermelo and Lolium multiflorum var. Archie were the quickest to germinate and attained significantly (p < 0.01) higher values of FG%, of 45% and 50%, respectively, at 600 mS m⁻¹, indicating higher salt tolerance than the other species. Overall, increasing salinity reduced the germination performance of all grass species tested; however, Archie and Ermelo showed higher potential for rehabilitation of coalmine spoils irrigated with saline water.