Genetic Variations among Fleabane (Conyza bonariensis (L.) Cronquist) Populations in Jordan and Their Susceptibility Levels to Contact Herbicides

A field demonstration and pot experiments were implemented to assess the effect of paraquat, oxadiazon, oxyfluorfen herbicides in controlling selected populations fleabane Conyza bonariensis (L.), grown central valley Jordan. mature seeds collected from six investigated sites (five Jordan named P1, P2, P3, P4, P5, one University Campus P6). Only proved be C. via ITS assessment involved glasshouse at 2017 2019. Results showed that recommended or two-fold higher rates (2.5 5 kg ha−1) paraquat failed affect weed plants a date palm orchard located Tal-al-Ramel Central Valley. Paraquat, oxyfluorfen, oxadiazon (2.5, 3.3, ha−1, respectively), control same population experiments. Treated grew similarly untreated control, mostly due different genetic backgrounds. The other (University Research Station, al-Twal, Campus) effectively controlled with all herbicides. application 10-fold slightly injured resistant population. Seed DNA analysis region differences among populations. It indicated four are (P1, At time, two canadensis (a closely related species) Station (P2) al-Twal (P5), also was genetically distinct is concluded site developed resistance Thus, novel alternative practices necessary prevent its possible spread regions country obstruct development new herbicide-resistance