849 PB 390 PREEMERGENT WEED CONTROL IN CONTAINER-GROWN HERBACEOUS PERENNIALS
in HortScienceDuring the 1992 season six preemergent herbicides (Devrinol) at 4.5 and 9.1 kg/ha, Metolachlor (Pennant) at 4.5 and 9.1 kg/ha, Isoxaben (Gallery) at 1.1 and 2.3 kg/ha, Oxyfluorfen + Oryzalin (Rout) at 3.4 and 13.6 kg/ha, Oryzalin (Surflan) at 2.8 and 4.5 kg/ha and Trifluralin (Treflan) at 4.5 and 9.1 kg/ha, were tested on Rudbeckia fulgida “Goldstrum”, Digitalis purpurea “Excelsior”, Chrysanthemum maximum “Alaska”, Stokesia laevis “Blue Danube”, and Geum hybrids “Mrs. Bradshaw”. Gallery at both rates resulted in visual phytotoxicity on Chrysanthemum, Digitalis and stunting in Rudbeckia at the 2.3 kg/ha rate. During the 1993 season the same herbicides plus Oxadiazon (Ronstar) at 4.5 and 9.1 kg/ha, were tested on Achillea tomentosa, and Thymus pseudolanuginosus. Gallery and Pennent at both rates resulted in visual phytotoxicity and stunted growth on Thymus pseudolanuginosus. Rout at the 13.6 kg/ha rate resulted in visual phytotoxicity on Achilles tomentosa.
