The Influence of Encoding BT Corn Hybrids (Mon 810 Event) on the Infestation
of the Corn Borers in Egypt

• Magdy A. Massoud
• Department of Plant Protection, Faculty of Agriculture, Saba Basha, University of Alexandria, Egypt P.O. Box 21531 Bolkly-Alexandria, Egypt..
• The Third International Conference onIPM Role in Integrated Crop management and Impacts on Environment and Agricultural Products. 26-29 November 2005, Giza, Egypt.

Abstract

Field experiments were carried out to study the effect of encoding Bt gene in corn plants on the incidence of infestation of three corn borers namely : the pink corn borer Sesamia cretica Led., the purple-lined corn borer Chilo Agamemnon Bles. and the European corn borer Ostrinia nubilalis Hbn., during the subsequent growing seasons of 2002,2003 and 2004, in Kaha, Kaliobia governorate, Egypt. The XL214, MSA852 and CRN3505 hybrids (MON810 event) were planted as genetically modified with Bt toxin gene and as conventionÑÉ æÏæÏÉ ÇáÐÑÉ ÇáÃæÑÈíÉ Ýí ãÕÑal non-Bt plants, while Pioneer3062 hybrid was planted only as conventional non-Bt plants. The infestation rates of the three inspected corn borers were determined for all of the growing stages of tested plants during the different adopted sowing dates. The results clearly indicated that both the corn borers, Sesamia cretica Led and Chilo Agamemnon Bles. Were more deleterious to non-Bt plants sown on the end of May; their infestation level gradually decreased during June and July. As for Ostrinia nubilalis Hbn., the infestation highly increased with delaying the time of sowing date and exhibited the maximum level on plants sown on the end of June and July. The infestation of Sesamia cretica Led, Chilo Agamemnon Bles and Ostrinia nubilalis Hbn. was negligible or completely prevented in Bt plants (XL214, MSA852 and CRN3505) throughout the whole season and the different times of sowing dates, whereas encoding Bt.-gene acquired the plants about 93.6-100% reduction of the inspected infestation. Symptoms of few failed attempts of larvae to bore inside the plants were revealed, without the presence of any alive or dead larvae within the stalk. However, no significant difference of Sesamia cretica Led infestation were observed between Bt plants and the diazinon-treated ones of the tested hybrids during the 8-leaf and flowering stages. In preharvest stage, the pesticide treatment can't protect plants from Sesamia cretica Led. infestation. However, the infestation of Chilo Agamemnon Bles. and Ostrinia nubilalis Hbn. in diazinon-treated plants was increased significantly more than in Bt-plants and didn't differ significantly from the untreated check during all the conducted sowing dates. The maximum reduction percent of Sesamia cretica Led, Chilo Agamemnon Bles and Ostrinia nubilalis Hbn. infestation induced by diazinon was 69.86, 51.85, and 53.70%, respectively, indicating the insufficient efficacy of diazinon in controlling these corn borers. So, these results prove and assure the valued importance of cultivating Bt corn in Egypt.