Interacting Effects of Imidazolinone Herbicide Mixtures on Translocation in Pitted Morningglory (Ipomoea lacunosa)

Individual herbicides and all double combinations of imazaquin, imazethapyr, and imazapyr were applied alone and in combination to the foliage of pitted morningglory plants in order to evaluate potential influences on translocation. Unlabeled imazethapyr at 5.62 μg plant−1stimulated basipetal translocation of both14C-imazaquin and14C–imazapyr. Unlabeled imazaquin at 7.49 μg plant−1also increased basipetal translocation of14C–imazethapyr but did not influence14C–imazapyr translocation. No combination affected the amount of14C herbicide remaining in treated leaves or moving into foliage above treated leaves. Unlabeled imazapyr at 0.11 μg plant−1did not affect movement of either imazaquin or imazethapyr.