Bioherbicide potential of the aqueous extract of Ridolfia segetum (L.) Moris: Phytotoxic effect on the growth of Sinapis alba

Aromatic and medicinal plants (AMPs) are a valuable source of bioactive compounds with multiple applications. Their valorization allows the development of natural alternatives to chemical inputs and promotes sustainable and environmentally friendly agriculture.

Ridolfia segetum (L.) Moris, belonging to the Apiaceae family, is a plant traditionally used for its medicinal properties, but whose herbicidal potential remains unexplored. This study aims to evaluate the phytotoxic effect of its aqueous extract on the growth of Sinapis alba, a weed widely distributed in northern Morocco.

Phytochemical analysis of R. segetum highlighted the presence of several allelochemical compounds, including polyphenols, steroids, flavonoids, ascorbic acids, quinones, saponins, tannins, and terpenoids, suggesting a potential phytotoxic activity. To test its effect, three concentrations of aqueous extract (100%, 50%, and 25%), prepared at 50 g/L, were applied under laboratory conditions, with glyphosate as a positive control.

The results revealed significant inhibition of S. alba growth, especially with the 100% extract, resulting in a marked reduction in leaf numbers, root and shoot length, and fresh weight of seedlings. In addition, the content of chlorophylls a and b as well as carotenoids decreased significantly with increasing extract concentration. At the same time, the accumulation of oxidative stress markers (MDA, H₂O₂ and O^2-) in treated plants confirmed the inhibitory effect of the extracts on seedling physiology.

These results highlight the potential of R. segetum as a source of biodegradable bioherbicides, offering a natural alternative to chemical herbicides. This study thus contributes to the promotion of this aromatic and medicinal plant by proposing an ecological approach to the management of weeds.