Are herbicide mixtures unaffected by resistance? A case study with Lolium rigidum

Lolium rigidum, a grass weed species infesting winter field crops, has evolved resistance to the largest number of herbicide modes of action. In this study, 140 field populations of L. rigidum were screened with 14 herbicide treatments. Herbicide resistance at the recommended label dosage of pre-emergence (PRE), post-emergence (POST) and binary herbicide mixtures was considered present when plant survival was ≥6%. Plant survival to four acetyl-CoA carboxylase (ACCase) POST herbicides averaged across all populations was approximately 15%, indicating substantial herbicide resistance. In contrast, the mean survival to the PRE treatments was only 2%, reflecting effective control of L. rigidum. Herbicide … Continue reading Are herbicide mixtures unaffected by resistance? A case study with Lolium rigidum