Comparative germination performance of Cenchrus ciliaris and Schmidtia pappophoroides under controlled laboratory conditions

Abstract

Seed germination is a fundamental process, involving series of biochemical changes that lead to the development of a new plant. This study assessed the germination performance of two native perennial decreaser grass species, Cenchrus ciliaris L. and Schmidtia pappophoroides Steud., under controlled laboratory conditions. A completely randomised design was used to evaluate the germination performance of 500 florets per species, divided into five replicates per species incubated at 25 ± 2 °C under a controlled 12 h light dark photoperiod. Germination was monitored over 27 days, and eight germination metrics were evaluated that include first day of germination (T₀), median germination time (T₅₀), mean germination time (MGT), and day of last germination ( $$\:{\text{T}}_{\text{g}}$$ ), time spread (TS), peak germination percentage (PGP), synchrony index (Z), and final germination percentage (FGP). The results showed that C. ciliaris germinated earlier (T₀ = 3.0 days) and completed germination earlier ( $$\:{\text{T}}_{\text{g}}$$ = 15.4 days) than S. pappophoroides (T₀ = 3.4 days; $$\:{\text{T}}_{\text{g}}$$ = 21.0 days). Similarly, the time spread observed in C. ciliaris (TS = 12.40) was relatively shorter in comparison to S. pappophoroides (TS = 17.60 days). Peak germination percentage was correspondingly higher in C. ciliaris (8.20%) than in S. pappophoroides (6.00%). However, germination synchrony was comparable (p > 0.123) between species, C. ciliaris (0.16) and S. pappophoroides (0.14). Final germination percentage differed significantly, with C. ciliaris achieving 31.40%, compared to 22.40% in S. pappophoroides. Overall, the findings revealed that differences in germination performance exist between the two species. Although several metrics did not differ significantly, C. ciliaris consistently achieved a higher final germination percentage and faster completion of germination. However, further evaluation under field conditions is recommended to validate laboratory performance within the degraded Kalahari ecosystems.