Essential Oil Composition, Antioxidant and Allelopathic Activities of Cleome droserifolia ( Forssk .) Delile

People rely on the synthetic chemical pesticides in most of the agricultural practices, which have a serious problem on human health and ecosystem. Essential oil (EO), derived from wild plants, offers a new opportunity to explore eco‐friendly green biocides. This study aimed to characterize the chemical constituents of EO from Egyptian ecospecies of Cleome droserifolia ( Forssk. ) Delile and evaluate its antioxidant and allelopathic potential. The EO was extracted from aerial parts by hydrodistillation and analyzed by GC/MS. To assess the allelopathic potential, EO concentrations from 50 to 200 μL L −1 were tested on Trifolium repens and three weeds. Antioxidant activity was determined using DPPH. Hydrodistillation yielded 0.64 % of dark yellow oil, which comprises 35 compounds, in which sesquiterpene was a major class and represented by 61.97 % of the total essential oil. Moreover, the dominant sesquiterpenes are cis ‐nerolidol, α ‐cadinol, δ ‐cadinene, and γ ‐muurolene. The speed of germination index, shoot and root length of clover and weeds were reduced in a concentration‐dependent manner. The IC 50 values of C. droserifolia EO on germination of T. repens , Cuscuta trifolii , Melilotus indicus , and Chenopodium murale were 181.6, 183.5, 159.0, and 157.5 μL L −1 , respectively. From the obtained data, we concluded that C. droserifolia EO could provide a hope to produce environment‐friendly bioherbicide as well as a natural resource of antioxidants.