Allelotoxic activity of Eucalyptus rostrata Schlecht. on seed germination and seedling growth of Chenopodium album L. and Portulaca oleracea L.

Eucalyptus rostrata is known to contain various substances that are allelopathic. The allelopathic effect of leaf
(ERLAE) and bark (ERBAE) of Eucalyptus rostrata aqueous extracts was evaluated for their potential uses as
control on seed germination and seedling growth of two noxious weeds; Chenopodium album and Portulaca
oleracea. The biological activity of the two types of extracts on germination efficiency differs with respect to the
type of extract and the recipient species. Assertively, the consequence of the extracts on the two weeds was in the
following order: ERLAE > ERBAE and almost, the action was highly effective and significant in C. album
compared to P. oleracea. The reduction in plumule and radical lengths for the two recipient plants in the present
study may be attributed to the reduced rate of cell division and cell elongation due to the presence of
allelochemicals in the aqueous extracts. In conclusion, the obtained results in the present study may share in
solving the problem of heavy use of synthetic herbicides via application and trying of a number of promising
medicinal plants rich in allelochemicals such as E. rostrata.