Hardseededness and seed dormancy of Townsville Lucerne (Stylosanthes humilis) selections

Abstract

Eleven selections of Townsville lucerne (Stylosanthes humilis H.B.K.) were grown with Rhodes grass (Chloris gayana Kunth.) in field plots near Townsville, North Queensland, and seed was collected at monthly intervals. At the first sampling in July hard seed contents were high (74-99 per cent), but declined steadily to values of 31-49 per cent in November. Dormancy, as assessed from the germination of scarified seed, was also high in July but declined rapidly so that by September the selections showed from 89 per cent to 99 per cent germination. The significance of hardseededness and dormancy in seed preservation and the importance of hardseededness in commercial sowings is discussed.