Influence of herbicide mixture on composite weed flora and yield of transplanted rice under system of rice intensification

The present investigation was carried out during Kharif season of 2014–15 and 2015–16 at farmer's field Nadia, West Bengal, India with the rice variety ‘IET-4786’ by following System of Rice Intensification (SRI) methodology to study the effect of ready mix herbicide on growth of composite weed flora and productivity of transplanted puddle rice. Eight treatments were assigned in randomized block design with three replications. Results revealed that ready mix application of Pyrazosulfuron ethyl 0.75%+ Pretilachlor 30% WG @ 1.75 and 3.5 kg ha⁻¹ resulted better weed management and highest Weed Control Efficiency (WCE). Pyrazosulfuron ethyl 0.75% + Pretilachlor 30% WG @ 3.50 kg ha⁻¹ yielded a maximum of 4.33 t ha⁻¹ of rice followed by farmers ’practice (4.32 t ha⁻¹) and lower dose of Pyrazosulfuron ethyl 0.75% + Pretilachlor 30% WG @ 1.75 kg ha⁻¹ (4.29 t ha⁻¹). These findings are useful in conditions when farmers skip or miss pre-emergence herbicide application, good weed control efficiency and higher yield can still be obtained with the pre-mix application of Pyrazosulfuron ethyl 0.75% + Pretilachlor 30% WG @ 1.75 kg ha⁻¹ in transplanted puddle rice.