Determination of the herbicide resistance status of local population of barnyard grass (Echinochloa crus-galli) weeds collected from paddy fields in different regions of Türkiye using rapid method

In this study, the resistance status of local barnyard grass (Echinochloa crus-galli (L.) P. Beauv.) collected from 63 paddy fields in the Marmara (Balıkesir, Çanakkale, Edirne) and Blacksea (Samsun, Çorum, Sinop) regions of Türkiye to cyhalofop-butyl, penoxulam and pinoxaden were determined in herbicide-amended media under in vitro coniditions. Among the populations tested, the highest resistance was observed with penoxulam (73.01%), followed by cyhalofop-buyl (52.38%) and pinoxaden (46.03%). High-level resistance to all three herbicides tested was observed at only one population, which was obtained from Edirne/Ipsala/Sarpdere location. The highest level of resistance to at least one herbicide was found in Çanakkale (76.16%), followed by Balıkesir (66.67%), Edirne (62.5%), Sinop (50%), Samsun (43.59%) and Çorum (26.67%). This study reveals the current resistance levels of E. crus-galli populations to common herbicides in various rice-growing regions of Türkiye, providing valuable insights for the development of effective weed control strategies. Additionally, the rapid testing method developed in this study could be a valuable tool for future research providing a quick and cost-effective way to determine herbicide resistance in important weed species that infest various host plants.