Effect of the Bioherbicide Pseudomonas fluorescens D7 on Downy Brome (Bromus tectorum)

Abstract

Downy brome (Bromus tectorum) is one of the most problematic invasive plant species in the United States. Downy brome invasions are associated with reductions in diversity and an increase in fire intensity. Bioherbicides that are reported to effectively control downy brome have been developed. Pseudomonas fluorescens strain D7 is one such bioherbicide that is of significant interest to land managers in Wyoming. A spatially replicated field trial was performed to identify what effect D7 has on downy brome in Wyoming. The field trial showed no response of any downy brome fitness metrics to D7; only commonly used synthetic herbicides were able to reduce downy brome cover. This work suggested D7 may not be a viable product for downy brome control, or more information may be needed about the field conditions required for a positive result when using D7. © 2019 The Society for Range Management