Efficacy of post emergence herbicides on direct-seeded rice (Oryza sativa) in Chhattisgarh plains of India

A field experiment was conducted in Inceptisol during wet seasons of 2006 and 2007 at University Farm, Indira Gandhi Krishi Vishwavidyalaya, Raipur, Chhattisgarh, India to standardize post emergence herbicide use in direct-seeded rice. At 50–60 days after sowing broad leaf weeds dominated the weed flora by more than 50% during both the years. The dose of azimsulfuron 50 DF + surfactant applied @ 30–40 g ha⁻¹ was superior to other doses during first and second year. Higher grain yield up to 55.63 and 72.47% in first and second year, respectively, over untreated check and weed control efficiency up to 73.69% was obtained at this rate of application. Combination of fenoxaprop-p-ethyl with ethoxysulfuron and chorimuron + metsulfuron also proved better than lower doses of azimsulfuron 50 DF.