Sequential herbicide strategies for mitigating weed stress in direct-seeded rice (Oryza sativa) systems

Effective sequential herbicide strategies are required for stable productivity in the cultivation of direct-seeded rice (DSR; Oryza sativa). A field experiment was conducted in Sheikhupura, Pakistan to evaluate sequential pre-emergence (PRE) and post-emergence (POST) herbicides in DSR. A split plot experiment was arranged with three PRE herbicides treatments, which were the main plots: (1) M1, Pendimethalin 30 EC @ 2500 mL ha−1; (2) M2, Triafamone + Ethoxysulfuron-ethyl 30% WP @ 185 g ha−1; and (3) M3, No PRE (control). There were also seven POST herbicide treatments, which were the sub-plots: (1) T1, Bispyribac-sodium + Bensulfuron-methyl @ 250 g ha−1 + Fenoxaprop-P-ethyl @ 500 mL ha−1; (2) T2, Bispyribac-sodium + Cyhalofop-butyl @ 250 g ha−1 + Fenoxaprop-P-ethyl @ 500 mL ha−1; (3) T3, Metamifop + Cyhalofop-butyl 20% EC @ 1000 mL ha−1; (4) T4, Fenoxaprop-P-ethyl + Penoxsulam @ 625 mL ha−1; (5) T5, Penoxsulam + Cyhalofop-butyl @ 2000 mL ha−1; (6) T6, Florpyrauxifen-benzyl + Cyhalofop-butyl @ 2750 mL ha−1; and (7) T7, untreated weedy check (control). Sequential herbicide application significantly improved weed control and crop growth. The combination M2T6 recorded lowest weed density and highest weed control efficiency. Weed index declined to 12%, while rice grain yield reached 6752 kg ha−1. Sequential herbicide integration proved effective for sustainable weed management and yield improvement in direct seeded rice.