Fendioxypyracil, a new and systemic PPO-inhibiting herbicide for X-spectrum weed control

Fendioxypyracil is a new protoporphyrinogen oxidase (PPO; HRAC Group 14)-inhibiting herbicide developed to expand post-emergence weed control options. The compound combines a pyridine-based core with an aryloxy side chain, resulting in high biological activity. Physiological profiling and enzyme assays confirmed PPO inhibition as its mode of action, with strong inhibition of both PPO1 and PPO2 from Amaranthus tuberculatus and higher potency than saflufenacil, particularly against PPO2. Greenhouse and field studies demonstrated broad-spectrum efficacy against major broadleaf and grass weeds at low use rates. These results indicate that fendioxypyracil represents a valuable new PPO inhibitor for integrated weed management.

Greenhouse evaluations demonstrated high efficacy of fendioxypyracil against key grass weeds, including wild oat (Avena fatua), crabrass (Digitaria Sanginalis), goosegrass (Eleusina indica) and barnyard grass (Echinochloa crus-galli), as well as strong control of major broadleaf species. Physiological characterization and enzyme inhibition assays confirmed PPO as the primary site and mode of action, with IC₅₀ values lower than those of the commercial standard saflufenacil for both PPO isoforms.

Fendioxypyracil represents a next-generation PPO inhibitor with broad-spectrum and systemic activity, offering a valuable new tool for integrated weed management. Its high biological activity and efficacy across multiple weed taxa supports its potential to enhance on-farm weed control strategies and contributes to resistance management programs. © 2026 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.