Corn grains collected from North Delta Governorates Behaira, Sharkya and Menofya), Upper Egypt (Sohag, Assuit and Qena) and imported corn (Argentina, USA and Hungary) were investigated and studied under Egyptian storage conditions. Moisture content and kind of variety are considered the primary factors affecting development of storage fungi in grains and consequently influence grains damage percentage i.e. germ, mold, insect and heat damage. This percentage was increased gradually by increasing storage period (0,2,4,6,8,10,and 12 months) of all tested samples (local or imported). Moisture content increased in all samples up to 8 months storage period then decreased gradually. Using thiourea and propionic acid formula (Salmo-Nil-Dry) as preservative materials led to clear significant decrease in damaged grains percentage compared with untreated ones during storage. After 6-12 months storage period, thiourea gave the best effect on stored com grains, while propionic acid formula proved to be highly effective in preventing damaged grains after 12 months storage period and greatly decreased damage percentage on imported corn samples during all storage periods (0,2,4,6,8,10 and 12 months). The tested fungicides, (Topsin M70 and Somi 8) successively and significantly decreased the percentage of the total damage. Each fungicide at the tested rate significantly decrease grain invasion. Both fungicides caused the least
percentage of damage after storage period 12 months.