Ecology and herbicide tolerance of the native weeds that cause pimelea poisoning

Abstract

Three annual species of native Pimelea (Thymelaeaceae) cause intermittent but serious problems for cattle producers in inland Australia. The causal toxin and related compounds have been known for decades but no well-defined relationship between the incidence and abundance of the plant in pastures and levels of animal morbidity has been established.
We report on early efforts to germinate the seeds reliably so that appropriate toxicity and herbicide trials can be conducted. A strong embryonic dormancy has been shown to exist in fresh seed, particularly in P. simplex. Also, germination and recruitment conditions for P. elongata are apparently very different to those favourable to recruitment of P. trichostachya, even though they often grow in close proximity.