Does pesticides pollution affect rice plants in the southern coastline of the Caspian Sea?

Considering the increasing rice consumption in the world and also the excessive application of pesticides to increase production, an experiment was conducted to determine the pesticide residues and their effects on nitrogen, potassium and phosphorus content of Hashemi, Khazar and Gohar (SA13) rice cultivars, in a factorial design at randomized complete block design with three replications. In this study, rice plants were treated with three pesticides including insecticide Diazinon, herbicide Butachlor and fungicide Tricyclazole which are commonly used in the paddy fields of the southern coastline of the Caspian Sea, with standard concentrations recommended for these pesticides. The results indicated that the impacts of different pesticides on nitrogen, phosphorus and potassium contents in rice grains of Hashemi and Khazar cultivars were not significantly different. However, the nitrogen content reduced significantly in Gohar cultivar treated by Butachlor and Tricyclazole in comparison with control (p≤0.01). Determination of pesticides residues showed that Diazinon residue in white grains of Hashemi, Khazar and Gohar cultivars was lower than recommended limit determined by Codex (0.1 ppm), and also Tricyclazole amount was below the limit of detection. Therefore, using pesticides in permissible limits is strongly recommended. However, it cannot be concluded that using pesticides; even in permissible limits, does not have dangerous impacts over time on living organisms of the Caspian ecosystem.