Widespread Occurrence of Glyphosate-Resistant Hairy Fleabane (Erigeron bonariensis L.) in Colombia and Weed Control Alternatives

Glyphosate, the most applied herbicide globally, offers effective non-selective and post-emergent weed control. Evolution of herbicide-resistant weeds is commonly associated with recurrent application herbicides same mode action. Native to South America, hairy fleabane (Erigeron bonariensis L.) problematic in this sub-continent has previously been confirmed glyphosate resistant. This research aimed at characterizing glyphosate-resistant populations, thus estimating frequency resistance, resistance levels identifying alternatives control populations. Glyphosate characterization was initially conducted on ten suspected populations collected plantain, banana, cassava, passionfruit, papaya, drybean crops. Two resistant were selected further characterized through dose-response tests; addition, response alternative (paraquat, glufosinate, 2,4-D, pyraflufen-ethyl, mesotrione) determined. All surveyed survived (≥80% individuals) recommended rate 1080 g ae ha−1; conversely, five from non-cropping areas effectively controlled rate. Dose-response tests estimated factors 3.15- 22.3-fold versus susceptible population. Interestingly, profile detected hormesis responses field-recommended rates. The pyraflufen-ethyl mesotrione.