Competitiveness of herbicide-resistant and herbicide-susceptible kochia (Kochia scoparia [L.] Schrad.) under contrasting management practises

Abstract

Kochia (Kochia scoparia [L.] Schrad.), also known as fireweed, belvedere, burning bush, railroad weed or summer cypress, was first introduced to the USA in the early 1900s as an ornamental plant from Eurasia (Undersander et al. 1990). Although it has been grown as a drought-resistant forage crop, this annual plant is a particularly problematic weed in small grain-cropping systems in North America. Kochia is drought-tolerant, has a deep taproot, and its branched stem can grow to a height of almost 2.5 m, making this species an effective competitor for light, nutrients, and soil moisture. Additionally, kochia can produce thousands of seeds per plant and is able to spread these seeds long distances very quickly due to its ability to disperse (as a “tumbleweed”) during windstorms.