Effect of Post Emergence Application of Glyphosate on Weed Control and Yield of Herbicide Tolerant Transgenic Stacked Maize Hybrids

Field experiments were conducted during kharif 2009 and rabi 2009-10 at Tamil Nadu Agricultural University, Coimbatore to evaluate the weed control efficiency of various weed management practices and yield of transgenic stacked maize hybrids. Treatments consisted of two transgenic hybrids named Hishell and 900 M Gold applied with glyphosate as early post emergence application (POE) at 900, 1800 and 3600 g a.e ha -1 compared with non-transgenic counterpart maize hybrids applied with pre-emergence (PE) atrazine at 0.5 kg ha -1 followed by one hand weeding (HW) on 40 DAS and with and without insect management. Among the treatments higher weed control efficiency was achieved by POE application of glyphosate at 900, 1800 and 3600 g a.e ha -1 and higher grain yield was recorded with POE application of glyphosate at 1800 g a.e ha -1 in transgenic 900 M Gold and 3600 g a.e ha -1 in transgenic Hishell during kharif 2009 and rabi 2009-10 seasons, respectively.