The Ecology and Control of Perennial Pepperweed (Lepidium latifoliumL.)

Abstract

Field experiments were conducted for the control of perennial pepperweed with tillage and herbicides. Perennial pepperweed infests a wide range of soils and plant communities. These studies were conducted in native hay meadows, with wild-flooding irrigation and saline/alkaline soils. Such meadows are typical of livestock ranches throughout the Intermountain Area. Tillage with periodic disking over a 2-yr period resulted in no permanent reduction in perennial pepperweed cover. Applications of 2,4-D or glyphosate eliminated perennial pepperweed seed production and greatly reduced top growth but had no permanent influence on cover of the weed by the second season following application. Applications of chlorsulfuron in the spring at flowering, in late summer after hay harvesting, or in the autumn, were effective in suppressing perennial pepperweed for 2 yr or more following application.