Response of Common Wildflower Species to Postemergence Herbicides

Wildflowers attract wildlife, increase pollinator habitat, and enhance the aesthetic value of landscape. Wildflower establishment is increasingly part an effort to reduce maintained turfgrass on golf courses, lawns, other environments. Weed competition decreases wildflower results in poor long-term stands. Research was conducted a controlled environment investigate tolerance species common postemergence herbicides. included California poppy ( Eschscholzia californica Cham.), sunflower Helianthus annuus L.), cornflower Centaurea cyanus garden coreopsis Coreopsis lanceolata partridge pea [ Chamaecrista fasciculata (Michx.) Greene], plains tinctoria Nutt.), purple coneflower Echinacea purpurea (L.) Moench], rosering gaillardia Gaillardia pulchella Foug.), violet prairie clover Dalea Vent.). Herbicides evaluated were fluazifop at 0.28 kg⋅ha –1 a.i., mesotrione 0.14 clopyralid 0.29 bentazon 0.56 halosulfuron 0.053 imazaquin 0.42 a.i. An untreated check for comparison. Excessive damage (≥ 53% phytotoxicity) observed all response clopyralid, except poppy. Fluazifop relatively safe (≤ 19% phytotoxicity, regardless herbicide) species; however, resulted ≥ 40% aboveground biomass reduction several species. Common susceptible (37% 73% respectively) 87% respectively), but species, phytotoxicity ≤ 18%. Although both only 18% coneflower, 43% 44% recorded. Mesotrione 11% 24% reduction). Results suggest high variability across herbicides considered, may prompt new investigation safety utility within field production scenarios.