ملخص
This study was conducted in the Researches Station of the Faculty of Agriculture-Tripoli University during the winter and summer of 2017-2018 and 2018-2019. The purpose of this study is to identify weed species spreading at the agricultural and non-agricultural zones of the station, which is with a total a of 45.5 hectares, This study was a completion of a previous study which was conducted at the same station during winter of 2012-2013 and 2013-2014, where 58 species of weed were detected in agricultural zones. In the current study 38 species of weeds were detected, and not included in the previous study, those species were spread in the subject zones of the survey, and belonging to 18 vegetarian families.The results of this study shows that the dominance of the family Fabaceae with 8 species, followed by the families Poaceae, Brassicaceae, Caryophyllaceae, and Asteraceae with 7, 3, 3, 2 species respectively. In this study, the species of yellow sorrel (Oxalis compressa thunb) belonging to the family Oxalidaceae were recorded for the first time from Libya, such species were found in the non-agricultural zones at the station in 16-02-2019. Through the field observation and follow-up, we discovered that some of weed species used to grow in small quantities (as stated in the previous study) become widespread inside station and around it, in addition to that, we found that plowing is the sole method used to control weeds inside the station, which seems to be without any efficient results in preventing the spread of weeds. The main purpose of this study is to provide vital information about controlling weed so as to identify its species, its growing nature and the production and spread of its seeds. Such information will help in identifying the most efficient method of controlling and decreasing the spread of weeds. Therefore, it is necessary to have the above – mentioned information before the implementation of any weed control programs by the interested in this domain. Key Words:Weed survey, Yellow sorrel (Oxalis compressathunb), weed spread.