Conyza bonariensis (L.) Cronq. (syn. of Erigeron bonariensis L.) is a difficult-to-control summer weed species in the cropping belt of south-eastern Australia. Herbicide resistance may be affecting the ability to control C. bonariensis in the agricultural region of north-eastern Victoria; therefore, a survey was conducted to evaluate resistance to herbicides from several mode-of-action groups. Of the populations collected, 40% were resistant to glyphosate at 1080 g ha^–1. Chlorsulfuron failed to control any of the populations collected. Further research identified multiple herbicide resistance to glyphosate, chlorsulfuron, metsulfuron-methyl and sulfometuron-methyl in five of nine populations fully characterised. Resistance was not found to 2,4-D, clopyralid or paraquat. There was no correlation between prevailing land use and the frequency of glyphosate-resistant populations, suggesting that resistance had been selected in multiple production systems. The high frequency of resistance could explain the difficulty experienced in controlling C. bonariensis across north-eastern Victoria and demonstrates the importance of integrated weed management to manage this weed.

Conyza bonariensis（L.）（Erigeron bonariensis L.的同种）是澳大利亚东南部种植带中一种难以控制的夏季杂草物种。在维多利亚州东北部的农业地区，除草剂的抗性可能会影响防治博纳木梭菌的能力。因此，进行了一项调查以评估几个作用模式组对除草剂的抗性。在收集的人群中，有40％的人对1080 g ha ^–1的草甘膦有抗性。氯磺隆无法控制所收集的任何种群。进一步的研究确定了9个种群中有5个种群对草甘膦，氯磺隆，甲基磺隆和甲基磺隆的多种除草剂抗性。未发现对2,4-D，氯吡格雷或百草枯有抗药性。普遍的土地利用与抗草甘膦种群的发生频率之间没有相关性，这表明已经在多种生产系统中选择了抗药性。抗药性的高频率可能解释了在维多利亚州东北部控制邦纳梭菌的过程中遇到的困难，并表明了综合杂草处理对这种杂草进行管理的重要性。