INTEGRATED MANAGEMENT OF FIMBRISTYLIS MILIACEA (L.) VAHL IN RICE SYSTEMS: SEED ECOLOGY, HERBICIDE SENSITIVITY, AND CROP COMPETITION EFFECTS

This study investigated the biological characteristics of Fimbristylis miliacea (L.) Vahl (globe fringerush), a prevalent paddy weed, and evaluated its competitive effects on rice growth to inform targeted control strategies.Seed dormancy patterns were characterized through chemical treatments (Sodium hypochlorite (NaClO), Sodium hydroxide (NaOH), Gibberellic acid (GA3)) and germination assays under varying soil moisture conditions.Herbicide sensitivity was assessed via pot experiments, while field trials quantified the weed's impact on rice physiology (plant height, tillering, yield) across competition gradients.Results demonstrated that 0.25% NaClO, 0.4% NaOH, and 800 mg/L GA3 effectively broke seed dormancy, achieving germination rates of 31.70%,25.07%, and 20.23%, respectively.Optimal germination (89.63%) occurred at 100% soil humidity, but submersion inhibited emergence.The F. miliacea population exhibited susceptibility to MCPA dimethylamine salt (ED90 = 396.9g ai/ha), bentazone (314.9 g ai/ha), and propanil (2779.9g ai/ha), but resistance to triafamone, penoxsulam, florpyrauxifen-benzyl, and benzobicyclon.Increasing weed density progressively reduced rice plant height, effective panicles, and yield, with panicle weight significantly declining at densities > 60 plants/m 2 .These findings identify F. miliacea as a dormant-seeded species controllable by selective herbicides, while highlighting its yield-limiting competitive effect in rice production systems.