Abstract

Gallery DF (isoxaben), Snapshot DF (isoxaben + oryzalin), and Snapshot TG (isoxaben + trifluralin) were applied to four species in 1991 and to nine species in 1992 of container-grown herbaceous flowering perennials to evaluate efficacy, phytotoxicity, and effect on plant growth. Surflan AS (oryzalin) and Treflan 5G (trifluralin) were used as standard herbicide checks. Gallery was applied at 0.56, 0.84, and 1.12 kg ai/ha (0.5, 0.75, and 1.0 lb ai/A). Snapshot DF and Snapshot TG were applied at 2.8, 4.2, and 5.6 kg ai/A (2.5, 3.75, and 5.0 lb ai/A). Coreopsis was not affected by any herbicide treatment either year. Painted daisy was injured by all treatments except Snapshot TG at 2.5 lb ai/A and Treflan. Gallery at 1.12 kg ai/ha (1.0 lb ai/A) and Snapshot DF at 5.6 kg ailha (5.0 lb ai/A), injured all species except coreopsis and hibiscus. Surflan injured gloriosa daisy (1991 only), chrysanthemumhollyhock, hibiscus, and painted daisy. Snapshot TG applied at 5.6 kg ai/A (5.0 lb ai/A) injured hollyhock. Height of coreopsis, shasta daisy, gloriosa daisy, and columbine was not affected or only slightly reduced by any treatment. Hollyhock, hibiscus, painted daisy, and chrysanthemum were generally shorter in containers treated with Snapshot DF at 4.2 kg/ha or higher rates.