Abstract

Field. experiments were conducted on the clay loam soils of Tamil Nadu Agricultural University, Coimbatore during kharif (June-Sep) and rabi (Oct-Jan) seasons of 1984-85. The herbicide treatments were dicamba at 0.075, 0.125, 0.200, 0.300, and 0.500 kg ha¹ and 2, 4-DEE at 0.200, 0.300, 0.600 and 0.800 kg ha¹ during kharif and 0.200, 0.300, and 0.500 kg ha¹ of dicamba and 0.300, 0.600 and 0.800 kg ha of 2,4-D EE during rabi applied individually and in all combinations. Butachlor 1.5 kg ha¹ and hand weeding twice treatments were included in rabi for comparison. Dicamba +2,4-D EE mixture at 0.300+ 0.600 gave the highest grain yield of 5261 and 4892 kg ha during kharif and rabi seasons, respectively. The grain yields with hand weeding twice (4798 kg ha¹) and butachlor treatments (4816 kg ha-1) were comparable with higher doses of individual application of these herbicides during rabi season. The highest weed control efficiency and index were observed in dicamba + 2,4-D EE mixture at 0.5+0.8 kg ha-1 applied in both seasons closely followed by 0.3+0.60 kg ha-1

Keywords: Herbicides, Dicamba, 2, 4-D EE, Effect, Weeds, Rice Yield