Allelopathic Potential of Aqueous Extracts from Fleagrass (<i>Adenosma buchneroides</i> Bonati) against Two Crop and Three Weed Species

Abstract

This study aimed to assess the phytotoxic potential of fleagrass (Adenosma buchneroides) on weeds and crops. We assessed the effects of applying aqueous extracts of fleagrass on the seed germination and seedling growth of three weeds (Bidens pilosa, Paspalum thunbergia, and Bromus japonicus) and two crops (Oryza sativa and Zea mays). The influence of six doses of fleagrass aqueous extract on seed germination and seedling growth was assessed through a Petri dish experiment. The aqueous extract of fleagrass was qualitatively characterized using widely targeted metabolomics analysis and found to mainly comprise flavonoids, phenolic acids, alkaloids, polysaccharides, phenylpropanoids, terpenoids, phenolamides, and quinones. The mean IC50 for crop seed germination was 168,796, and the mean IC50 for weed seed germination was 11,454. The inhibition effect on the tested species, from highest to lowest, followed the order of B. japonicus > B. Pilosa > P. thunbergii > O. sativa > Z. mays. These results indicate the remarkable species-specific sensitivity of seed germination and seedling growth to fleagrass extract treatment, and that crops are more tolerant than weeds. Elucidation of the details of the fleagrass–weed/crop interaction can serve as a basis for intercropping fleagrass with crops in weed management strategies aimed at controlling weeds.

Keywords

• <i>Adenosma buchneroides</i>
• seed germination
• allelopathy
• aqueous extract