Abstract
BACKGROUND: Indaziflam is an alkylazine herbicide used to control annual bluegrass (Poa annua L.). Several locations in the southeastern USA reported poor annual bluegrass control following treatment with indaziflam during autumn 2015. A series of controlled environment experiments were conducted to confirm putative resistance to indaziflam in annual bluegrass collected from these field locations. RESULTS: Indaziflam (25 g ha−1) effectively controlled all putative-resistant annual bluegrass collections when applied preemergence (PRE), but was ineffective when applied early-postemergence (< 2.5 cm plant height; BBCH scale = 1; EPOST). In agarose-based plate assays, EPOST I50 values for putative-resistant collections ranged from 2424 to 4305 pm compared with 633 pm for the herbicide-susceptible control; therefore, resistance indexes (R/S) ranged from 3.8 to 6.8. Resistant collections were not controlled by foramsulfuron, flumioxazin, glyphosate, glufosinate, metribuzin, pronamide, or simazine applied EPOST. Indaziflam content in herbicide-susceptible annual bluegrass was greater than a resistant collection from 0 to 10 days after treatment (DAT). Susceptibility was not restored when resistant collections were treated with indaziflam plus 1-aminobenzotriazole (10 mg L−1), tebuconazole (1510 g ha−1), or malathion (400 g ha−1). CONCLUSIONS: This is a first report of resistance to indaziflam in any plant. Additionally, we confirm that these annual bluegrass collections are resistant to several other herbicidal modes-of-action. It is unclear if this multi-herbicide resistance is due to a single resistance gene, multiple resistance genes, non-target site mechanisms, or a combination thereof. Additional research to better understand resistance mechanisms in these annual bluegrass collections is warranted.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 2049-2057 |
| Number of pages | 9 |
| Journal | Pest management science |
| Volume | 76 |
| Issue number | 6 |
| DOIs | |
| State | Published - Jun 1 2020 |
Bibliographical note
Funding Information:The authors would like to acknowledge Doug Karcher for assistance in non-linear regression analysis of metabolism data. Several individuals also assisted in maintaining plant material used in these experiments: Greg Breeden, Roberto Viggiani, Robert Trigiano, Sarah Boggess, Dallas Taylor, and Mitchell Riffey. The authors would like to thank Qin Yu for reviewing this manuscript prior to submission. Lastly, the authors would like to thank Bayer Environmental Science as well as the University of Tennessee Office of AgResearch for their financial support of this research. Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the University of Tennessee.
Funding Information:
The authors would like to acknowledge Doug Karcher for assistance in non‐linear regression analysis of metabolism data. Several individuals also assisted in maintaining plant material used in these experiments: Greg Breeden, Roberto Viggiani, Robert Trigiano, Sarah Boggess, Dallas Taylor, and Mitchell Riffey. The authors would like to thank Qin Yu for reviewing this manuscript prior to submission. Lastly, the authors would like to thank Bayer Environmental Science as well as the University of Tennessee Office of AgResearch for their financial support of this research. Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the University of Tennessee.
Publisher Copyright:
© 2020 Society of Chemical Industry
Keywords
- annual bluegrass
- cellulose biosynthesis
- indaziflam
- non-target site resistance (NTSR)
- resistance
- turfgrass
PubMed: MeSH publication types
- Journal Article