The name of the compound and allelopathic effect of metabolites produced by common ragweed (Ambrosia artemisiifolia L.)

Purpose. To identify the phytochemical composition of the aboveground biomass of Ambrosia artemisiifolia L., the effect of its root exudates on major crops within agroecosystems, and the competitiveness of this weed species compared to other plants. Methods. Allelopathic, chemical, physiological-biochemical, analytical, and statistical methods. Results. The biomass of A. artemisiifolia contains a high concentration of essential physiologically active components, with coumarins being the most prevalent at 2.97%. The roots of A. artemisiifolia release protocatechuic acid, n-hydroxybenzoic acid, vanillic acid, syringic acid, n-coumaric acid, and ferulic acid into the rhizosphere. Phytotoxic extracts from the vegetative organs of A. artemisiifolia reduced seed germination in winter pea by an average of 37–50%, in maize by 27–40%, in sorghum by 17–22%, and in sugar beet by 12–28%. Root phytotoxic extracts and rhizosphere soil extracts significantly decreased seed germination in the studied crops: in winter pea by 71% and 78%, respectively, in maize by 42% and 38%, respectively, in sugar beet by an average of 26%, and in sorghum by 33% and 16%. Sunflower demonstrated the highest resistance, with seed germination reduced by only 7%, 5%, and 4% when treated with phytotoxic extracts from the stems, leaves, and inflorescences of A. artemisiifolia, respectively. Phytotoxic extracts from the soil and roots reduced sunflower seed germination by 11% and 6%, respectively. The highest competitiveness against the allelopathically active components of the weed species was exhibited by yellow mustard (Sinapis alba), sorghum, and creeping couch grass (Elymus repens), as their phytotoxic soil extracts reduced A. artemisiifolia seed germination by 75%, with creeping couch grass and sorghum extracts reducing germination by 88% and 68%, respectively. Conclusions. Water extracts from the vegetative and generative organs of A. artemisiifolia contain significant amounts of physiologically active components that impact the quality of seed germination in the studied crops. It was found that sunflower seeds are resistant to the allelopathically active substances of the A. artemisiifolia. Yellow mustard, sorghum, and creeping couch grass demonstrate resistance to the phytotoxic components of A. artemisiifolia, due to their high levels of phytochemical compounds capable of inhibiting seed germination of this highly allelopathic weed.