Glyphosate tolerant and insect resistant transgenic Bt maize efficacy against shoot borer, cob borer and non-target insect pests

Abstract

Introducing Bt insect resistance genes into hybrid maize seems to be the most feasible and effective technique accessible to control the pest. Transgenic stack hybrid maize (MON 89034X NK 603) was developed by Monsanto for checking yield losses of maize crop to increase productivity. Transgenic stack hybrid maize was claimed to have both insect protection and herbicide tolerant traits to provide protection to the crop from target pests and also provide effective weed management. MON 89034X NK 603 is 2nd generation glyphosate tolerant with Bt maize technology effective against lepidopteron insect pests with “dual mode of action”. A field experiment was carried out at ICAR-Directorate of Weed Research, Jabalpur for two years during Kharif (rainy season) 2009 and 2010 to evaluate the efficacy of transgenic stack hybrid maize (MON 89034X NK 603) against shoot borer (Chilo partellus), cob borer (Helicoverpa armigera), non-target insect pests and beneficial insects. Treatments consisted of two transgenic stacked hybrids named ‘Hishell’ and ‘‘900M Gold’’ with two conventional hybrids namely ‘Proagro-4640’ and ‘‘HQPM-1’’. Artificial infestation of Chilo partelus revealed complete absence of stem borer infestation in all the transgenic entries of ‘Hishell’ and ‘900M Gold’ with less than one leaf injury score (LIS), while in other conventional entries, stem borer infestation was observed and LIS was more than one. Hlicovepa armigera infestation was also not observed on transgenic hybrids whereas in the remaining non-transgenic maize treatment, significant attack of Helicoverpa armigera was observed in the range of 37 to 56%. These transgenic entries were not found resistant to aphids and grass hoppers. Beneficial insects were observed to visit transgenic Bt maize and conventional maize entries with no significant difference.