Abstract
The results of studying the effect of cold storage periods (one ,two ,three) months at (-5,zero,and 5 0c ) and kind of water (hardwater ,tap water ,river water,and well water)on emulsion stability of Chlorpyrifos and Alphacypermethrin and amixture of Chlorpyrifos and Cypermethrin reaveld that increasing the cold storage period produce a thicker separation layer in a Alphacypermethrin emulsion which reached 5.28 ml when using well water after three month storage at -5c in comparison with control 4.0 ml .,followed by the mixture of Chlorpyrifos and Cypermethrin with an average of separation layer thickness reached 4.48 ml .when stored for three months at 5c using well water in comparison with control 3.8ml well water was more effective on emulsion stability and the average separation layer thickness were 4.13,4.64.and 3.13 ml . for Alphacypermethrin and the mixture of Chlorpyrifos and Cypermethrin and Chlorpyrifos respectively.