-Conyza canadensis is a widespread weed species forming dense populations in most regions of China. Petri dish bioassays with aqueous extracts of the aboveground parts and roots of C. canadensis at three concentrations (0.05, 0.1, and 0.2 g mL -1) were undertaken to investigate the autotoxic effects of C. canadensis, and the possible effects on three dominant native weed species, Plantago asiatica, Digitaria sanguinalis and Youngia japonica. The results showed that seed germination and the shoot length of three native species were significantly inhibited by aqueous extracts of C. canadensis at almost all concentrations that generally increased with increasing extract concentration. However, the seed germination and shoot length of C. canadensis itself was not significantly affected by the same extracts at all concentrations. These results suggested that the potential allelopathic compounds produced by the tissue of C. canadensis may contribute to its invasive success in invading southern China.Keywords: invasive alien weed, allelopathy, petri dish bioassay. Palavras-chave: planta daninha invasiva alienígena, alelopatia, bioensaio em placa de Petri. RESUMO -

environment. It is one of the hotspots in Ecology and Agronomy. In this paper, we have retrieved from the Web of Science (WoS) SCI-E database the allelopathy-related studies (1960-2019). The Annual Number of Publications, Authors, Countries, Institutions, Journals and Keywords were analyzed by the bibliometric method to determine the research trends and hotspot changes in this field over the past 6 decades. From 1960-2019, the WoS database included 4,114 studies in the field of plant allelopathy. During this period of 60 years, the number of publications has gone through three stages: (i). Initial Stage (1960-1990), (ii). Growing Stage (1991-2009) and (iii). Stable Stage (2010-2019). The studies were conducted by 9,956 authors at 2,166 institutions across 100 countries. The United States, China, and Japan have the highest number of publications. The top three institutions with the highest number of publications are the Chinese Academy of Sciences, Kagawa University and USDA, USA. The top three authors are H. Kato-Noguchi, F.A. Macias, and C.H. Kong. The major Journals in this field are: (i). Allelopathy Journal, (ii). Journal of Chemical Ecology and (iii). Plant and Soil. The results of keyword clustering showed that the main research directions in this field are: (i). Metabonomics undergoing allelopathy, (ii). Functions of allelopathy substances, (iii). Molecular biology, (iv). Allelopathy of aquatic plants, (v). Alien plants invasion and (vi). Application of plant allelopathy in agroforestry production. Plant allelopathy is a research field that aims to maintain stable development. Future studies should focus on strengthening the cooperation among international scholars in plant allelopathy research and improving the output in frontier and hotspot areas.