Epyrifenacil, a new systemic PPO-inhibiting herbicide for broad-spectrum weed control

Abstract

Epyrifenacil is a novel PPO-inhibiting herbicide discovered and developed by Sumitomo Chemical. Epyrifenacil belongs to the pyrimidinedione chemical class and has a unique three-ring structure. It is systemically active on a broad range of weeds including grass weeds and some target-site-based PPO-inhibitor resistant broadleaf weeds. Its systemic action is mediated by a phloem movement of the active form of epyrifenacil. In addition, epyrifenacil's vapor action is sufficiently low to not cause an off-target movement to nontarget sensitive crops. It is expected that epyrifenacil will contribute to global food production in the near future. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Keywords: PPO; epyrifenacil; herbicide resistance; pyrimidinedione; systemic action.

Figure 1

Pyrimidinedione PPO inhibitors. The data following the common names include the year of ISO common name approval and the inventor company.

Figure 2

Epyrifenacil inhibition of Palmer amaranth PPO2 (wild‐type). Numbers following the herbicides are median inhibitory concentration (IC₅₀) (nm) ± 95% confidence interval. Each datum is an average of three replications.

Figure 3

Vapor drift detection by bioassay. 2 weeks after placing in the chamber.

Figure 4

Epyrifenacil biokinetics on wild soybeans. DAT, d after treatment

Figure 5

Epyrifenacil biokinetics on corn plants.

Figure 6

Grass activity in glasshouse pot trial. Late‐post application. Spray volume: 200 L ha⁻¹. Crop oil concentrate added at 1% (v/v).

Figure 7

Activity on PPO resistant Palmer amaranth in glasshouse pot trial. Mid‐post application. Spray volume: 200 L ha⁻¹. Crop oil concentrate added at 1% (v/v).

Figure 8

PPO‐inhibitor resistant Palmer amaranth field trial. Early‐post application. Spray volume: 189 L ha⁻¹. Crop oil concentrate added at 0.5% (v/v).

Figure 9

Southern crabgrass field trial. Mid‐post application. Spray volume: 236 L ha⁻¹. Crop oil concentrate added at 1% (v/v).