Investigation on the effects of water quality on chlorpyriphos (EC 40.8%)‎‏ ‏and ‎imidacloprid (SC 35%) stability indexes‎

Water is an important carrier for pesticide spraying. Physical and chemical properties of water can affect the quality control indexes and the efficiency of diluted pesticides. So, the study of the water characteristics in different regions of the country is very important. For this purpose, water samples from Mazandaran, Fars, Isfahan, Markazi, Guilan, Qazvin, Kerman (two regions), Khorasan Razavi, Yazd and Tehran provinces were collected. The effects of water hardness, pH and electrical conductivity (ec) on the quality control of two insecticides chlorpyrifos (EC 40.8%) and imidacloprid (SC 35%) as prevalent and highly-consumption formulations in the country were studied. The results of water hardness test showed that water sample from Kerman with 2255 ppm and then the water of Fars with 744 ppm had the highest hardness and sample of water in Guilan region with 60 ppm had the lowest degree of hardness in water tested areas. The emulsion stability of chlorpyrifos in water samples from Qazvin, Guilan and Khorasan Razavi (with low water hardness), showed no creaming, while in provinces which hardness was high, including Kerman, Fars and Yazd, creaming at diluted insecticides were high. The suspensibility of imidacloprid in water samples showed that suspension in water from Kerman, Fars and Yazd samples was unacceptable and suspensions from the other areas were acceptable.