Abstract:

To address the production challenge posed by resistant barnyard grass in rice fields，this study investigated the control efficacy of the novel HPPD inhibitor herbicide flusulfinam in combination with propanil，florpyrauxifen-benzyl，propanil·triasulfuron，and triasulfuron against resistant barnyard grass，aiming to identify effective strategies for managing resistance in rice fields. It was shown that plant control rates were 81.9%-95.0% at 14 days after treatment （DAT），84.7%-94.8% at 21 DAT，and fresh weight control rates reached 87.1%-97.7% at 35 DAT. Among the treatments，treatment 1 consistently showed the lowest efficacy across all evaluation periods， whereas treatment 4 achieved the highest control efficacy at 14，21，and 35 DAT，which was significantly （p0.05） higher than that of Treatment 1. Furthermore，when scientifically formulated with adjuvant agents，flusulfinam demonstrated enhanced efficacy against resistant barnyard grass，with the optimal control performance achieved when combined with propanil. At 14 DAT，fixed-point surveys of seedling growth indicated that all formulations had no significant impact on rice growth indicators such as leaf age，tiller number，or plant height，demonstrating good safety.

Key words: rice field, flusulfinam, resistant barnyard grass, control efficacy, safety