Natural herbicides: medicinal oils as an eco-friendly tool for controlling weeds associated with wheat plant
摘要
Weeds are a major challenge in crop production due to their management costs and potential yield losses. The extensive use of synthetic chemical herbicides has frequently led to negative impacts on both the environment and human health concerns. In response to these concerns, recent research has intensified promising approach involves identifying natural compounds with allelopathic properties that could serve as natural herbicides. Medicinal oils, such as black cumin, garlic, thyme, and moringa oils, have offered as potential sustainable tools for weed management. Hence, two greenhouse experiments were conducted along two successive winter seasons to evaluate the bioherbicidal effects of these oils on wild oat and mallow weeds, as well as their impact on wheat plants. Results showed that all tested oils significantly reduced the fresh and dry weights of both weed species, with varying sensitivity observed between both weeds. The reduction in weeds biomass increased with higher oil concentrations. Specifically, moringa, black cumin, and thyme oils at 15% concentration exhibited the strongest suppression of weed growth at the first age (45 days after sowing), while moringa, thyme, and garlic oils at 15% were most effective at the second age (70 days after sowing). Furthermore, treatments with black cumin oil at 15%, moringa oil at 10% and thyme oil at 15% improved wheat yield traits compared to unweeded controls. Gas chromatography–mass spectrometry (GC–MS) analysis identified seven common fatty acids in the oils, including arachidic, caprylic, cis-10-heptadecenoic, linoleic, linolenic, oleic, and palmitic acids. Among these, linoleic, oleic and palmitic acids were most abundant and may responsible for the observed herbicidal activity.