Common cocklebur (Xanthium strumarium) Resistance to Selected ALS-Inhibiting Herbicides

摘要

Five biotypes of common cocklebur that were not controlled with acetolactate synthase (ALS)-inhibiting herbicides were tested in green house and laboratory studies to determine the mag- nitude of resistance and cross-resistance to four ALS-inhibiting herbicides. In vivo inhibition of ALS was also evaluated. Based on phytotoxicity, all five ALS-resistant biotypes of common cocklebur were ＞390 times more resistant than the susceptible biotype to imazethapyr. However, only four of these biotypes were also resistant to another imidazolinone, imazaquin.