Bio-efficacy evaluation of herbicide resistant transgenic corn hybrids for crop safety and productivity (MON 89034 × NK603).

Herbicide resistant corn plants confer tolerance to glyphosate by production of the glyphosate-tolerant CP4 5-enolpyruvylshikimate3phosphate synthase (CP4 EPSPS) proteins. As an initiative on transgenic corn in India, transgenic stacked corn hybrids evolved by Monsanto India Ltd., NK603 is the glyphosate tolerant technology for the effective weed management system. The plant becomes tolerant to the herbicide while all other weed flora suppressed after application of glyphosate. The transgenic corn hybrids were evaluated during kharif 2009 and rabi 2009-10 at experimental site of Tamil Nadu Agricultural University, Coimbatore, India. Glyphosate was applied as early POE application at 900, 1800 and 3600 g a.e/ha in Hishell and 900 M Gold transgenic corn hybrids compared with non-transgenic counterparts with PE atrazine at 0.5 kg/ha + HW on 40 DAS and with and without insect management. Early POE application of glyphosate at 900, 1800 and 3600 g a.e/ha reduced weed density, dry weight and WCE in transgenic Hishell and 900 M Gold corn hybrids compared to non-transgenic corn hybrids with herbicidal treatment. Higher grain yield was recorded with POE application of glyphosate at 900, 1800 and 3600 g a.e/ha in Hishell and 900 M Gold transgenic corn hybrids. Average yield obtained in transgenic corn hybrid was 10 t/ha and conventional transgenic corn hybrid was 8 t/ha.