Fates of fruits and seeds of Ligustrum lucidum W.T.Ait. and L. sinense Lour. maintained under natural rainfall or irrigation

Abstract

Factors influencing germination and seed survival of Ligustrum lucidum W.T.Ait. and L. sinense Lour., two serious environmental weeds in subcoastal eastern Australia, were investigated in a series of experiments conducted under natural rainfall regimes (field experiments) and under irrigation in a growth tunnel. In the field experiments, no seedlings of either species were observed where seeds and intact fruits had been surface-sown; seedlings originated only from shallowly buried seeds and fruits, with generally higher levels of emergence from seeds. Where soil moisture levels were maintained at or above field capacity, however, moderate to high levels of germination occurred from surface-sown seeds and fruits of both species. Total seedling emergence varied considerably between years for each moisture regime. Seeds of both species were short-lived, with most (>95%) not persisting for 12 months in any case.