Efficacy of Herbicide Mixture to Control Mixed Weed Flora in Direct Seeded Puddled Rice

Field studies conducted during kharif 1997 and 1998 at experimental farm of CSK Himachal Pradesh Krishi Vishvavidyalaya, Palampur revealed that while cyhalofopbutyl 90 g ha⁻¹ (20 DAS) was superior in decreasing the dry weight of Echinochloa crusgalli, 2,4-DEE 1.0 kg ha⁻¹ (20 DAS) was superior to control sedges and broadleaf weed species when applied alone. Tank mix application of 2,4-DEE with cyhalofopbutyl reduced the efficiency of the latter to reduce dry matter of E. crusgalli and of total weeds indicating their antagonistic effect. Although sequential application of cyhalofopbutyl 75 g ha⁻¹ (20 DAS) fb. butachlor 1.0 kg+2,4-DEE 1.0 kg ha⁻¹ (30 PAS) being at par with cyhalofopbutyl at 90 g ha⁻¹ (20 DAS) fb. 2,4-DEE 1.0 kg ha⁻¹ (30 DAS) was effective to reduce the dry matter of all weeds except Cyperus iria, but cyhalofopbutyl at 90 g ha⁻¹ (20 DAS) when applied alone resulted in significantly highest grain yield of rice by causing significant reduction in dry matter of E. crusgalli, the major and most competitive weed.