Germination Response to Leaching in Dormant Seed of Trifolium subterraneum L

DORMANCY in Trifolium subterraneum L. (subterranean clover) has been reviewed by Morley1. Dormancy in imbibed seed is usually high at harvest maturity but declines with time at rates which differ with strain. High temperatures are inhibitory to germination, and the younger the seed the lower is the inhibiting temperature. Ballard2,3 has shown that dormancy in new seed is readily overcome by cold treatment and also by subjecting the imbibed seed to an atmosphere enriched with carbon dioxide at temperatures of up to 25° C; above 25° C, carbon dioxide is unable to abolish completely the inhibition of germination at high temperatures. Dormancy may also be relieved by heat treatment of dry seed4, by removal of the seed coat5 and by other means1. The presence of an inhibitor in the seed which is soluble in water has in the past been questioned6 if not discounted2.