| Summary: | Essential (EOs) can be considered as an alternative tool to control weeds, as they are eco-friendly and safe bioherbicides. Based on their herbicidal efficacy against coffee weeds in the prescreening under in-vitro, lath-house and field experimentations, five aromatic plants namely, Cymbopogon citratus, C. martinii, C. winterianus, Eucalyptus citriodora and Thymus schimperi were selected to identify their chemical composition using Gas Chromatography-Mass Spectrometry. The chromatographic analysis revealed the presence of 45 compounds in C. citratus oil dominated with citral (84.86%) from the subclasses of trans-Citral and cis-Citral. Thirty-three compounds were fractionated and identified in C. martinii oil containing geraniol (55.27%), trans-Geranyl acetate (16.82%), (6R,7R)-Bisabolone (7.23%) and trans-.beta.-Ocimene (6.18%) as the main inherited components. The EO from C. winterianus contained 47 compounds with citronellal (31.31%), geraniol (21.24%), citronellol (12.06%) and elemol (6.68%) as the major component. Similarly, a total of 52 compounds were identified from the EO of E. citriodora containing two major compounds namely, citronellal (76.93%) and citronellol (15.24%). The EO from T. schimperi were composed of 32 compounds with carvacrol (72.55%) and thymol (9.12%) as the main constituents. The present finding indicated that herbicidal activities of the EOs might be attributed to their fingerprint components such as citral (3,7-dimethylocta-2,6-dienal), geraniol (2E)-3,7-dimethylocta-2,6-dien-1-ol), citronellal (3,7-dimethyloct-6-enal), citronellol (3,7-Dimethyloct-6-en-1-ol), carvacrol (2-methyl-5-propan-2-ylphenol) and thymol (5-methyl-2-propan-2-ylphenol). Therefore, these bioactive agents have the potential to be used as herbicides to manage weed species in coffee farms for the future.
|
|---|