The tolerance of transplanted lanceleaf coreopsis (Coreopsis lanceolata L.), ox-eye daisy (Chrysanthemum leucantheum L.), purple cone flower [Echinacea purpurea (L.) Moench.], and blanket flower (Gaillardia aristata Pursh) to metolachlor was determined in field trials. Metolachlor at 4.5 kg·ha-1 (maximum use rate) and 9.0 kg·ha-1 (twice the maximum use rate) did not reduce stand or flowering of any wildflower species after one or two applications, although plants developed transient visible injury. Combining metolachlor with the broadleaf herbicides simazine or isoxaben resulted in unacceptable injury and stand reduction, especially in ox-eye daisy. Metolachlor plus oxadiazon was less injurious to the wildflowers than metolachlor plus either simazine or isoxaben. Treatments containing metolachlor controlled yellow nutsedge (Cyperus esculentus L.) by at least 89% in both experiments. Treatments containing isoxaben controlled eclipta (Eclipta alba L.). 100% in both studies. Chemical names used: N-[3-(1-ethyl-1-methylpropyl)-5-isoxazolyl]-2,6-dimethoxybenzamide (isoxaben); 2-chloro -N-(2-ethyl-6-methylphenyl) -N-(2-methoxy-1-methylethyl)acetamide (metolachlor); 3-[2,4-di-chloro-5-(1-methylethoxy)phenyl]-5-(1,1-dimethylethyl)-1,3,4-oxadiazol-2-(3 H) -one (oxadiazon); 6-chloro -N,N' -diethyl-1,3,5-triazine-2,4-diamine (simazine).
If the inline PDF is not rendering correctly, you can download the PDF file here.