Control options for weeds such as annual ryegrass (Lolium rigidum) in winter wheat crops are limited due to the development of herbicide resistance. This study reports on the potential of shepherd's purse as a source for novel compounds for weed control. The extract of shepherd's purse was tested for phytotoxicity against annual ryegrass, wild radish (Raphinus raphanistrum) and wheat (Triticum aestivum). The growth of all test species was significantly reduced at all extract concentrations of 5 % and above. The stability of the extract was also tested. There was no significant change in phytotoxicity of the extract over a period of 256 days. The negative effect of shepherd's purse extract on annual ryegrass root growth was also observed in trays filled with soil. The 400 % extract inhibited shoot length and weight by at least 70 % compared to the control. In addition to biological studies, research into the chemical components of shepherd's purse extract was also conducted. Bioassay guided fractionation determined that the ethyl acetate fraction was the most phytotoxic. All fractions were analysed by GC/MS and tentative identifications of detected compounds are presented here, along with discussion about their potential contribution to the overall phytotoxicity of the extract.
|Number of pages||12|
|Publication status||Published - Jul 2009|