fatemeh shakib

In order to assess the effects of different pesticides on nutrient levels of rice، three pesticides (Diazinon، Tricyclazole and Butachlor) which are commonly used in paddy fields in Iran were selected in a randomized complete block with 3 replicates in field condition. The result indicated that the impact of different pesticides on total protein and nitrogen، phosphorus and potassium content in brown and white rice grain of varieties of Hashemi and Khazar did not show significant differences. Also، results indicated that nitrogen content was significantly reduced in Gohar variety using herbicide of Butachlor in white and brown grain of rice، and for fungicide Tricyclazole only in brown rice at 1% level compared with control. Phosphorus content increased significantly in brown grain Gohar variety of rice for two pesticides of Butachlor and Tricyclazole at 5% levels and for Diazinon at 1% level but، potassium content was not significantly different in brown and white grain of rice. Also total protein content of brown grain was significantly reduced using three pesticides compared with control. The above results were due to the impacts of pesticides on leaf photosynthesis and mineral assimilation and transportation in plants. Also different crop cultivars in response to the same or different pesticides differed in morphology، physiology، growth habit and phenology. Therefore، any selective pesticide on a specific crop cultivar might induce injury to other cultivars.