Effects of Indaziflam on Native Species Seed Emergence
Category: Research Poster
Author(s): Sammy Tetrault
Presenter(s): Sammy Tetrault
Mentors(s): Cynthia Brown, Lauren Myers
Bromus tectorum (cheatgrass), is an annual grass and invasive species that increases risk and severity of wildfires. Indaziflam is a pre-emergence herbicide that is soil applied and inhibits cellulose production, preventing radicle formation. Indaziflam is effective against B. tectorum, but it is not clear how it affects other species. The purpose of this study is to identify the impact of indaziflam on emergence for 11 native and 3 invasive species, including B. tectorum, used as a positive control. To further our understanding of impacts, we investigated the interactions between functional group & rate and seed size & rate. Functional groups included invasive and native grasses and forbs. For our study, we sprayed indaziflam at varying rates (0 fluid oz/acre - 7 fluid oz/acre (2× normally applied rate)) on two types of trays, topsoil and sand mix. For each of 3 repetitions, we had 10 trays of each soil type. We took daily measurements of emergence, height, injury symptoms, and true leaf emergence. Using this data, we created generalized linear models in R. Our results indicate that there are significant interactions between rate & functional group and rate & seed size. Our model suggests that forbs may be more resilient than grasses and that small seeds may be more resilient than large seeds. These results can be used by land managers to better understand vulnerable species, and to inform application and restoration seeding timing, so as to mitigate harm to native species.