The germinability of soft seed of a number of strains of subterranean clover

Abstract

The effect of several seed treatments on germination of 13 strains of subterranean clover (Trifolium subterraneum) seed was examined at two constant temperatures in the laboratory. Tests were conducted on soft seed obtained after scarification of seed sampled on three occasions during the summer and autumn. Germinability varied between strains, but always increased with time after harvest ripeness. Leaching with water promoted some germination in even the most dormant seed. Treatment with carbon dioxide was effective in promoting germination at 20°C, but was less effective than leaching at 30°C. The results suggest that protection against germination by embryo dormancy is likely to be confined to conditions of comparatively high temperatures (>20°C) when associated with summer rains having little or no leaching effect.