Screening different plant species for herbicidal activity and identifying new allelochemicals with novel structures and phytochemical activity could be promising candidates for reducing the negative consequences of chemical herbicides. Our study aims to investigate the allelopathic substance(s) and herbicidal efficacy of Cleome rutidosperma DC. on rice filed weeds in the lab and glasshouse. The phytochemical constituents of the methanol extract of Cleome rutidosperma were analyzed by high-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (HPLC-ESI-QTOF-MS). The allelopathic effect of C. rutidosperma has been further studied on the germination and early development of five common rice field weeds: Echinochloa crus-galli (L.) P. Beauv., Fimbristylis miliacea (L.) Vahl, Oryza sativa f. spontanea Roshev., Leptochloa chinensis (L.) Nees, and Cyperus iria L. The seed germination and growth of tested weeds under lab and glasshouse conditions were compared to three concentrations of C. rutidosperma methanol extract at 2.5, 5, and 10% with the control (only distilled water). The results indicated the presence of 64 and 10 known chemicals using positive and negative ionization techniques, the majority of which were toxic. The inhibitory effect of C. rutidosperma was stronger in the lab than in the glasshouse. No seed germination of the tested species was observed when 10% C. rutidosperma extract was applied. The photosynthesis rate of C. iria exhibited a higher reduction (70.56%) compared to other species at higher doses (10%) of C. rutidosperma. These findings demonstrated that C. rutidosperma is a significant source of phytotoxic components and can be used to develop future bio-herbicides. The outcome of this study can be employed in the organic management of weeds and reduce our heavy reliance on synthetic herbicides.

• Abu Bakar, F. I., Abu Bakar, M. F., Abdullah, N., Endrini, S., & Fatmawati, S. (2020). Optimization of extraction conditions of phytochemical compounds and anti-gout activity of Euphorbia hirta L. (Ara tanah) using response surface methodology and liquid chromatography-mass spectrometry (LC-MS) analysis. Evidence-Based Complementary and Alternative Medicine, 2020, 4501261. https://doi.org/10.1155/2020/4501261

• Aslani, F., Juraimi, A. S., Ahmad-Hamdani, M. S., Hashemi, F. S. G., Alam, M. A., Hakim, M. A., & Uddin, M. K. (2016). Effects of Tinospora tuberculata leaf methanol extract on seedling growth of rice and associated weed species in hydroponic culture. Journal of Integrative Agriculture, 15(7), 1521-1531. https://doi.org/10.1016/S2095-3119(15)61256-4

• Awan, T. H., Ali, H. H., & Chauhan, B. S. (2022). Cyperus iria weed growth, survival, and fecundity in response to varying weed emergence times and densities in dry-seeded rice systems. Agronomy, 12(5), 1006. https://doi.org/10.3390/agronomy12051006

• Bose, A., Mondal, S., Gupta, J. K., Ghosh, T., Dash, G. K., & Si, S. (2007). Analgesic, anti-inflammatory and antipyretic activities of the ethanolic extract and its fractions of Cleome rutidosperma. Fitoterapia, 78(7-8), 515-520. https://doi.org/10.1016/j.fitote.2007.05.002

• Burrill, L. C., Cárdenas, J., & Locatelli, E. (1976). Field manual for weed control research. Oregon State University Press.

• Cheng, F., & Cheng, Z. (2015). Research progress on the use of plant allelopathy in agriculture and the physiological and ecological mechanisms of allelopathy. Frontiers in Plant Science, 6, 1020. https://doi.org/10.3389/fpls.2015.01020

• Clements, D. R., & Ditommaso, A. (2011). Climate change and weed adaptation: Can evolution of invasive plants lead to greater range expansion than forecasted? Weed Research, 51(3), 227-240. https://doi.org/10.1111/j.1365-3180.2011.00850.x

• Fukagawa, N. K., & Ziska, L. H. (2019). Rice: Importance for global nutrition. Journal of Nutritional Science and Vitaminology, 65, S2-S3. https://doi.org/10.3177/jnsv.65.S2

• Guiochon, G., & Beaver, L. A. (2011). Separation science is the key to successful biopharmaceuticals. Journal of Chromatography A, 1218(49), 8836-8858. https://doi.org/10.1016/j.chroma.2011.09.008

• Hasan, M., Ahmad-Hamdani, M. S., Rosli, A. M., & Hamdan, H. (2021). Bioherbicides: An eco-friendly tool for sustainable weed management. Plants, 10(6), 1212. https://doi.org/10.3390/plants10061212

• Hasan, M., Mokhtar, A. S., Mahmud, K., Berahim, Z., Rosli, A. M., Hamdan, H., Motmainna, M., & Ahmad-Hamdani, M. S. (2022). Physiological and biochemical responses of selected weed and crop species to the plant-based bioherbicide WeedLock. Scientific Reports, 12, 19602. https://doi.org/10.1038/s41598-022-24144-2

• Hasan, M., Mokhtar, A. S., Rosli, A. M., Hamdan, H., Motmainna, M., & Ahmad-Hamdani, M. S. (2021). Weed control efficacy and crop-weed selectivity of a new bioherbicide WeedLock. Agronomy, 11(8), 1488. https://doi.org/10.3390/agronomy11081488

• Hu, Y., Na, X., Li, J., Yang, L., You, J., Liang, X., Wang, J., Peng, L., & Bi, Y. (2015). Narciclasine, a potential allelochemical, affects subcellular trafficking of auxin transporter proteins and actin cytoskeleton dynamics in Arabidopsis roots. Planta, 242, 1349-1360. https://doi.org/10.1007/s00425-015-2373-6

• Huang, S., Zhu, J., Zhang, L., Peng, X., Zhang, X., Ge, F., Liu, B., & Wu, Z. (2020). Combined effects of allelopathic polyphenols on Microcystis aeruginosa and response of different chlorophyll fluorescence parameters. Frontiers in Microbiology, 11, 614570. https://doi.org/10.3389/fmicb.2020.614570

• Jiang, Y., Ownley, B. H., & Chen, F. (2018). Terpenoids from weedy ricefield flatsedge (Cyperus iria L.) are developmentally regulated and stress-induced, and have antifungal properties. Molecules, 23(12), 3149. https://doi.org/10.3390/molecules23123149

• Juliano, L. M., Donayre, D. K. M., Martin, E. C., & Beltran, J. C. (2020). Weedy rice: An expanding problem in direct‐seeded rice in the Philippines. Weed Biology and Management, 20(2), 27-37. https://doi.org/10.1111/wbm.12196

• Juraimi, A. S., Uddin, M. K., Anwar, M. P., Mohamed, M. T. M., Ismail, M. R., & Man, A. (2013). Sustainable weed management in direct seeded rice culture: A review. Australian Journal of Crop Science, 7(7), 989-1002.

• Kato-Noguchi, H., Kobayashi, A., Ohno, O., Kimura, F., Fujii, Y., & Suenaga, K. (2014). Phytotoxic substances with allelopathic activity may be central to the strong invasive potential of Brachiaria brizantha. Journal of Plant Physiology, 171(7), 525-530. https://doi.org/10.1016/j.jplph.2013.11.010

• Krishnappa, K., & Elumalai, K. (2013). Mosquitocidal properties of Basella rubra and Cleome viscosa against Aedes aegypti (Linn.) (Diptera: Culicidae). European Review for Medical and Pharmacological Sciences, 17(9), 1273-1277.

• Lakshmanan, G., Sathiyaseelan, A., Kalaichelvan, P. T., & Murugesan, K. (2018). Plant-mediated synthesis of silver nanoparticles using fruit extract of Cleome viscosa L.: Assessment of their antibacterial and anticancer activity. Karbala International Journal of Modern Science, 4(1), 61-68. https://doi.org/10.1016/j.kijoms.2017.10.007

• Li, C., Tian, Q., u Rahman, M. K., & Wu, F. (2020). Effect of anti-fungal compound phytosphingosine in wheat root exudates on the rhizosphere soil microbial community of watermelon. Plant and Soil, 456, 223-240. https://doi.org/10.1007/s11104-020-04702-1

• Li, Z. R., Amist, N., & Bai, L. Y. (2019). Allelopathy in sustainable weeds management. Allelopathy Journal, 48(2), 109-138. https://doi.org/10.26651/allelo.j/2019-48-2-1249

• Lorenzo, P., Hussain, M. I., & González, L. (2012). Role of allelopathy during invasion process by alien invasive plants in terrestrial ecosystems. In Z. A. Cheema, M. Farooq, & A. Wahid, (Eds.), Allelopathy: Current trends and future applications (pp. 3-21). Springer. https://doi.org/10.1007/978-3-642-30595-5_1

• Mali, R. G. (2010). Cleome viscosa (wild mustard): A review on ethnobotany, phytochemistry, and pharmacology. Pharmaceutical Biology, 48(1), 105-112. https://doi.org/10.3109/13880200903114209

• Malmierca, M. G., McCormick, S. P., Cardoza, R. E., Alexander, N. J., Monte, E., & Gutiérrez, S. (2015). Production of trichodiene by Trichoderma harzianum alters the perception of this biocontrol strain by plants and antagonized fungi. Environmental Microbiology, 17(8), 2628-2646. https://doi.org/10.1111/1462-2920.12506

• Mendoza, N., & Silva, E. M. E. (2018). Introduction to phytochemicals: Secondary metabolites from plants with active principles for pharmacological importance. In T. Asao & M. Asaduzzaman (Eds.), Phytochemicals: Source of antioxidants and role in disease prevention. IntechOpen. https://doi.org/10.5772/intechopen.78226

• Mispan, M. S., Bzoor, M., Mahmod, I., Md-Akhir, A. H., & Zulrushdi, A. (2019). Managing weedy rice (Oryza sativa L.) in Malaysia: Challenges and ways forward. Journal of Research in Weed Science, 2, 149-167. https://doi.org/10.26655/jrweedsci.2019.3.6

• Motmainna, M., Juraimi, A. S., Uddin, M. K., Asib, N. B., Islam, A. K. M. M., Ahmad-Hamdani, M. S., Berahim, Z., & Hasan, M. (2021). Physiological and biochemical responses of Ageratum conyzoides, Oryza sativa f. spontanea (weedy rice) and Cyperus iria to Parthenium hysterophorus methanol extract. Plants, 10(6), 1205. https://doi.org/10.3390/plants10061205

• Motmainna, M., Juraimi, A. S., Uddin, M. K., Asib, N. B., Islam, A. K. M. M., & Hasan, M. (2021a). Assessment of allelopathic compounds to develop new natural herbicides: A review. Allelopathy Journal, 52(1), 19-38. https://doi.org/10.26651/allelo.j/2021-52-1-1305

• Motmainna, M., Juraimi, A. S., Uddin, M. K., Asib, N. B., Islam, A. K. M. M., Ahmad-Hamdani, M. S., & Hasan, M. (2021). Phytochemical constituents and allelopathic potential of Parthenium hysterophorus L. in comparison to commercial herbicides to control weeds. Plants, 10(7), 1445. https://doi.org/10.3390/plants10071445

• Motmainna, M., Juraimi, A. S., Uddin, M. K., Asib, N. B., Islam, A. K. M. M., & Hasan, M. (2021b). Allelopathic potential of Malaysian invasive weed species on weedy rice (Oryza sativa f. spontanea Roshev). Allelopathy Journal, 53(1), 53-68. https://doi.org/10.26651/allelo.j/2021-53-1-1327

• Motmainna, M., Juraimi, A. S., Uddin, M. K., Asib, N. B., Islam, A. K. M. M., & Hasan, M. (2021c). Bioherbicidal properties of Parthenium hysterophorus, Cleome rutidosperma and Borreria alata extracts on selected crop and weed species. Agronomy, 11(4), 643. https://doi.org/10.3390/agronomy11040643

• Mushtaq, W., Siddiqui, M. B., Hakeem, K. R. (2020). Allelopathy: Potential for green agriculture. Springer. https://doi.org/10.1007/978-3-030-40807-7

• Nadir, S., Xiong, H.-B., Zhu, Q., Zhang, X.-L., Xu, H.-Y., Li, J., Dongchen, W., Henry, D., Guo, X.-Q., Khan, S., Suh, H.-S., Lee, D. S., & Chen, L.-J. (2017). Weedy rice in sustainable rice production. A review. Agronomy for Sustainable Development, 37, 46. https://doi.org/10.1007/s13593-017-0456-4

• Prabha, S. B., Mohini, R., & Ramesh, K. M. R. (2017). Evaluation of in vitro antioxidant, antibacterial and anticancer activities of leaf extracts of Cleome rutidosperma. Research Journal of Pharmacy and Technology, 10(8), 2492-2496. https://doi.org/10.5958/0974-360X.2017.00440.1

• Ray, D. K., Mueller, N. D., West, P. C., & Foley, J. A. (2013). Yield trends are insufficient to double global crop production by 2050. PLOS One, 8(6), e66428. https://doi.org/10.1371/journal.pone.0066428

• Razavi, S. M., Imanzadeh, G., & Davari, M. (2010). Coumarins from Zosima absinthifolia seeds, with allelopatic effects. EurAsian Journal of BioSciences, 4, 17-22. https://doi.org/10.5053/ejobios.2010.4.0.3

• Reynolds, T. W., Waddington, S. R., Anderson, C. L., Chew, A., True, Z., & Cullen, A. (2015). Environmental impacts and constraints associated with the production of major food crops in Sub-Saharan Africa and South Asia. Food Security, 7, 795-822. https://doi.org/10.1007/s12571-015-0478-1

• Ruzmi, R., Ahmad‐Hamdani, M. S., & Bakar, B. B. (2017). Prevalence of herbicide‐resistant weed species in Malaysian rice fields: A review. Weed Biology and Management, 17(1), 3-16. https://doi.org/10.1111/wbm.12112

• Shah, A., & Smith, D. L. (2020). Flavonoids in agriculture: Chemistry and roles in, biotic and abiotic stress responses, and microbial associations. Agronomy, 10(8), 1209. https://doi.org/10.3390/agronomy10081209

• Shang, X.-F., Morris‐Natschke, S. L., Liu, Y.-Q., Guo, X., Xu, X.-S., Goto, M., Li, J.-C., Yang, G.-Z., & Lee, K.-H. (2018). Biologically active quinoline and quinazoline alkaloids part I. Medicinal Research Reviews, 38(3), 775-828. https://doi.org/10.1002/med.21466

• Sharma, A., Kumar, V., Shahzad, B., Tanveer, M., Sidhu, G. P. S., Handa, N., Kohli, S. K., Yadav, P., Bali, A. S., Parihar, R. D., Dar, O. I., Singh, K., Jasrotia, S., Bakshi, P., Ramakrishnan, M., Kumar, S., Bhardwaj, R., & Thukral, A. K. (2019). Worldwide pesticide usage and its impacts on ecosystem. SN Applied Sciences, 1, 1446. https://doi.org/10.1007/s42452-019-1485-1

• Sherwani, S. I., Arif, I. A., & Khan, H. A. (2015). Modes of action of different classes of herbicides. In A. Price, J. Kelton, & L. Srunaite (Eds.), Herbicides, physiology of action, and safety. IntechOpen. https://doi.org/10.5772/61779

• Siddique, M. A. B., & Ismail, B. S. (2013). Allelopathic effects of Fimbristylis miliacea on the physiological activities of five Malaysian rice varieties. Australian Journal of Crop Science, 7(13), 2062-2067.

• Singh, H., Mishra, A., & Mishra, A. K. (2016). Phytochemical screening, in vivo anthelmintic and anticonvulsant activity of Cleome viscosa Linn seeds extract. The Natural Products Journal, 6(3), 213-218. https://doi.org/10.2174/2210315506666160902163223

• Stephan, Z. A., Ruman, O. K., Al-Obaeidy, J. F. W., & Tawfeek, K. H. (2001). Nematicidal activity in some plant extracts against root-knot nematode Meloidogyne javanica on eggplant. Pakistan Journal of Nematology, 19(1/2), 81-86.

• Tamsir, N. M., Esa, N. M., Omar, S. N. C., & Shafie, N. H. (2020). Manilkara zapota (L.) P. Royen: Potential source of natural antioxidants. Malaysian Journal of Medicine and Health Sciences, 16(Supp6), 193-201.

• Travlos, I., Rapti, E., Gazoulis, I., Kanatas, P., Tataridas, A., Kakabouki, I., & Papastylianou, P. (2020). The herbicidal potential of different pelargonic acid products and essential oils against several important weed species. Agronomy, 10(11), 1687. https://doi.org/10.3390/agronomy10111687

• Upadhyay, R. K. (2015). Cleome viscosa Linn: A natural source of pharmaceuticals and pesticides. International Journal of Green Pharmacy, 9(2), 71-85. https://doi.org/10.22377/IJGP.V9I2.441

• Verdeguer, M., Sánchez-Moreiras, A. M., & Araniti, F. (2020). Phytotoxic effects and mechanism of action of essential oils and terpenoids. Plants, 9(11), 1571. https://doi.org/10.3390/plants9111571

• Wang, L., Sun, X., Peng, Y., Chen, K., Wu, S., Guo, Y., Zhang, J., Yang, H., Jin, T., Wu, L., Zhou, X., Liang, B., Zhao, Z., Liu, D., Fei, Z., & Bai, L. (2022). Genomic insights into the origin, adaptive evolution, and herbicide resistance of Leptochloa chinensis, a devastating tetraploid weedy grass in rice fields. Molecular Plant, 15(6), 1045-1058. https://doi.org/10.1016/j.molp.2022.05.001

• Weston, L. A., Alsaadawi, I. S., & Baerson, S. R. (2013). Sorghum allelopathy — From ecosystem to molecule. Journal of Chemical Ecology, 39, 142-153. https://doi.org/10.1007/s10886-013-0245-8

• Yang, N., He, X., Ran, L., Yang, F., Ma, C., Chen, H., Xiang, D., Shen, G., Zhang, P., He, L. & Qian, K. (2023). The mechanism of coumarin inhibits germination of ryegrass (Lolium perenne) and its application as coumarin–carbon dots nanocomposites. Pest Management Science, 79(6), 2182-2190. https://doi.org/10.1002/ps.7397

• Yang, Q., Yang, X., Zhang, Z., Wang, J., Fu, W., & Li, Y. (2021). Investigating the resistance levels and mechanisms to penoxsulam and cyhalofop-butyl in barnyardgrass (Echinochloa crus-galli) from Ningxia Province, China. Weed Science, 69(4), 422-429. https://doi.org/10.1017/wsc.2021.37

• Yu, J., Gao, H., Pan, L., Yao, Z., & Dong, L. (2017). Mechanism of resistance to cyhalofop-butyl in Chinese sprangletop (Leptochloa chinensis (L.) Nees). Pesticide Biochemistry and Physiology, 143, 306-311. https://doi.org/10.1016/j.pestbp.2016.11.001

• Ziska, L. H., Gealy, D. R., Burgos, N., Caicedo, A. L., Gressel, J., Lawton-Rauh, A. L., Avila, L. A., Theisen, G., Norsworthy, J., Ferrero, A., Vidotto, F., Johnson, D. E., Ferreira, F. G., Marchesan, E., Menezes, V., Cohn, M. A., Linscombe, S., Carmona, L., … Merotto Jr., A. (2015). Weedy (red) rice: an emerging constraint to global rice production. In D. L. Sparks (Ed.), Advances in agronomy (Vol. 129, pp. 181–228). Academic Press. https://doi.org/10.1016/bs.agron.2014.09.003