The increase in non-native invasive annual grasses, primarily Bromus tectorum (cheatgrass) and Taeniatherum asperum (medusahead) have placed western arid landscapes in peril. Invasive annual grasses have increased fire frequency, which prevents the reestablishment of sagebrush and reduces or eliminates native forbs and grasses (Link et al. 2006). Fire is linked to accelerated loss of sagebrush-steppe habitat and corresponding population declines of greater sage-grouse and other sagebrush obligate species (USFWS 2014; Lockyer et al. 2015). There has been limited success of traditional mechanical and chemical efforts to treat invasive grasses over the past 50 years. Weed suppressive bacteria, Pseudomonas fluorescens (P. fluorescens), as a host-specific biopesticide is a new technology in the integrated pest management toolbox for invasive annual grass control. P. fluorescens is a naturally occurring, ubiquitous, non-pathogenic soil bacterium shown through testing required for registration by the Environmental Protection Agency (EPA), to have specificity for cheatgrass, medusahead, and jointed goat grass (Aegilops cylindrical) (Kennedy et al. 1991; Johnson et al. 1993; Tranel et al. 1993; Gurusiddaiah et al. 1994). Unpublished studies have also shown that the biopesticide does not have a negative effect on non-target species or resources such as native grasses and forbs; however, there is a lack of peer-reviewed literature documenting impacts to non-target species and resources at landscape-scales.
Revised: November 6, 2015 |
Published: October 30, 2015