Allelopathy Journal

Control options for weeds such as annual ryegrass in winter wheat crops are limited due to the development of herbicide resistance. This study reports the potential of shepherd's purse (Capsella bursa-pastoris) as a source for novel compounds for weed control. The extract of shepherd's purse was tested for phytotoxicity against annual ryegrass and wild radish. All concentrations of 5% and above significantly reduced the growth of both test species. The stability of the extract was also tested, and there was no significant change in phytotoxicity of the extract over 256 days. The negative effect of shepherd's purse extract was also observed (in trays filled with soil) on annual ryegrass root growth. The 400% extract inhibited shoot length and weight by > 70% compared to the control.

In addition to biological studies, the chemical components of shepherd's purse extract were also investigated. Bioassay guided fractionation determined that the ethyl acetate fraction was most phytotoxic. All fractions were analysed by GC/MS and tentative identifications of detected compounds were conducted and the overall phytotoxicity of extract was also determined.