Factors Influencing the Germination of Six Perennial Grasses of Central New South Wales

Abstract

The effect of light, storage time, temperature regimes and water potential were examined on the germination of five native grasses of central New South Wales (Enteropogon ramosus, Bothriochloa macra, Elymus scabrus, Chloris truncata and Danthonia caespitosa), and one introduced grass (Eragrostis curvula).

Caryopses of E. ramosus, B. macra and E. curvula reached maximum germination soon after harvest. The remaining species reached maximum germination after 6-10 months storage. For all species, except E. scabrus, the effect of light on germination changed with duration of storage and with the presence of the lemma and palea. The viability of naked caryopses was reduced more rapidly than the viability of caryopses stored with the lemma and palea intact, for all tested species; E. scabrus and E. curvula were not tested. E. scabrus, C. truncata, D. caespitosa and E. curvula had greater than 50% germination over a range of alternating temperatures. E. ramosus had the narrowest temperature range for good germination, exceeding 50% germination only at temperatures above 30/20*#176 (day/night). E. ramosus and E. curvula germinated over a wider range of water potential than the other species. The germination of D. caespitosa, B. macra and C. truncata fell significantly at a water potential of -0.1 MPa.

It is concluded that temperature is likely to impede the germination of most of these grasses only in mid winter, and that soil water potential will probably have an overriding influence on the season of germination.