Cinmethylin

Cinmethylin is a herbicide that inhibits plant fatty acid biosynthesis. It effectively reduces the emergence rate and above-ground biomass of rigid ryegrass. By suppressing cell division in root meristems, cinmethylin kills weeds. It is active against rice field weeds, including Echinochloa crus-galli (L.) var. formosensis and Scirpus juncoides var. ohwianus, and is utilized in agricultural herbicide research.

Cinmethylin, applied at various rates (12-600 g ha⁻¹), selectively controls herbicide-sensitive and resistant rigid ryegrass populations (with LD₅₀ values of 20-165 g ha⁻¹). At 375 g ha⁻¹, cinmethylin effectively eradicates 130 field-collected rigid ryegrass populations, showing a 0% median survival rate, even for populations resistant to trifluralin. In doses of 188-400 g ha⁻¹, it selectively targets rigid ryegrass (S populations). Cinmethylin's tolerance in wheat (12-600 g ha⁻¹; 28 days after treatment) is mediated through cytochrome P450 activity. Moreover, cinmethylin (2.4-300 g a.i./hectare; applied 7 days after seeding) exhibits potent herbicidal activity against barnyardgrass (Echinochloa crus-galli (L.) var. formosensis) and small-flowered umbrella sedge (Scirpus juncoides var. ohwianus), achieving complete control of both weeds when applied pre- and early post-emergence at rates ≥75 g a.i./hectare; all tested rates achieve full control of ECHCS when applied pre-emergence.