Pages: 28-33

Abstract

This research was carried out at the Research Center for Agricultural Jihad and Natural Resources center of Golestan province and Farm No. 1 of Gorgan University of Agricultural Sciences and Natural Resources in 2011 and 2012. In this research, we used four cultivars of single Cros 704, Single Cross 403, sweet Maize hybrid variety chayse and Sweet Maize Variety (Armaghan 66), which was designed as split plot design and based on data on the number of polluted bushes and severity of pollution. Taking notes of different maize varieties were 30, 45 and 60 days after sowing date, respectively. Regarding the significance of infection severity in different planting dates in 2011 and 2012, and by comparing the mean comparison table in these two years, it was found that from the 3 selected time periods for corn planting, we had the least infection in the first date of 15 June and the highest level of infection in the last sowing date, August 15th.