Allelopathy of Parthenium hysterophorus L.Flowers on Abutilon theophrasti Medic.and Echinochloa crusgalli (L.) Beauv
The allelopathic effect of a Parthenium yh sterophorus L.flower aqueous extract and its ethyl acetate,n-buta-nol,and residual water fractions on seed germination and seedling growth of Abutilon theophrasti Medic.and Echinochloa crusgalli ( L.) Beauv.were studied by petri dish bioassays.Seeds of A.theophrasti and E.crusgalli failed to germinate in an aqueous extract of 50 g/L;the inhibition rate of root growth,shoot growth and fresh weight were 82.6%,89.1%and 84.3%for A.theophrasti,respectively and 91.7%,55.8%and 39.1% for E.crusgalli,respectively.With the butanol extract (50 g/L) the inhibition of root growth,shoot growth and fresh weight were 63.1%,80.0% and 58.3% for A. theophrasti,respectively,and 51.3%,26.7%and 23.3%for E.crusgalli,respectively.The germination rate of A.theo-phrasti and E.crusgalli were 13.3%and 33.3%,respectively.