Toxic properties and allelopathic activity of Melilotus officinalis (L.) Pall.

Melilotus officinalis (L.) Pall., known as yellow sweetclover (Fabaceae), is widely used in medicine and agriculture. At the same time, yellow sweetclover is a weed and invasive plant in Siberia. In Russia, M. officinalis is cultivated as a valuable medicinal, fodder and honey plant. Its widespread use is due to its high ecological plasticity. In recent years, an interest in cultivation of M. officinalis as a low maintenance multipurpose crop has increased in biological agriculture. The herb M. officinalis contains a rich complex of biologically active compounds. However, along with positive properties, this species, though with a rich chemical composition and high physiological activity, is toxic towards different groups of living organisms. The toxic effect of M. officinalis extracts is primarily due to the presence of coumarin. A high allelopathic activity of M. officinalis was revealed. The phytotoxic effect of herb extracts on germination of crop and weed seeds was studied in detail. Data on the fungicidal and insecticidal activity of M. officinalis were obtained. Laboratory and in situ studies showed that the aboveground part of M. officinalis is a potential source of biopesticides with a broad-spectrum effect (bioherbicidal, insecticidal and fungicidal).