Determination of ragweed (Ambrosia artemisiifolia L.) populations in Düzce

Common ragweed (Ambrosia artemisiifolia L.) is in the most harmful invasive species of Europe from Compositae (Asteraceae) family that is one of the most represented and crowded families in Plantae which has over 20 thousand species. It has been known an important issue in many countries including in Turkey with the first record in 1995 at the roadsides at Trabzon. Within this study, determination of common ragweed populations at the Düzce Province of Turkey where is located at the West Black Sea Region was aimed. The size of populations, largest and smallest plant's sizes and the other weeds in the area were recorded periodically at 10 km intervals throughout the province particularly where populations might be located. Moreover, a common ragweed contaminated area in Düzce University campus was observed and recorded for their biology monitoring at the same experimental units for three years since 2015. A total of 41 populations were identified throughout the province. While 82,6% of populations were found at sandy soil, 17,4% of them were found at clayey soil. In addition to common ragweed, fleabane species (Erigeron spp.) (18 population), black nightshade (Solanum nigrum), black locust (Robinia pseudoacacia) (9), and fat hen (Chenopodium album) (8) were found as the most density populations respectively. It is believed, common ragweed can possibly spread and occupy valuable agricultural lands due to appropriate climate conditions and human activities where have been pure.