Abstract
The results of studying the effect of tropical storage periods on acidity percentage of five insecticides Chlorpyrifos .Alphacypermethrin .and mixture of Chlorpyrifos and Cypermethrin .Malathion and Methomyl,showed that increasing the tropical storage periods leades to increase the acidity percentage of emulsifiable insecticides and the mean values of their acidity reached 0.322,0.275,o.265% for the mixture of Chlorpyrifos and Cypermetherin, Alphacypermetherin, and Chlorpyrifos respectively in comparison with the control which reached 0.049,0.037, 0.049% respectivley, while the acidity percentage of wettable powder insecticides reached 0.019,0.004% for malathion and methomyl as compared with the control 0.001,0.008% respectively.
