水稻抽穗前后施用农药情况对稻米中农药残留量的影响研究

水稻抽穗前、后施药的时期，农药种类，施药剂量与次数和稻米的安全性密切相关。供试的有机磷农药除敌敌畏未检出外，其余农药都在稻米中残留，残留量三唑磷〉乙酰甲胺磷〉甲胺磷〉毒死蜱〉吡虫啉〉敌敌畏。水稻抽穗前用药2次，甲胺磷、三唑磷均超标；用药3次，毒死蜱残留量与国家标准相当，乙酰甲胺磷未达标。上述农药剂量提高1倍，残留量提高30％～50％，用药2次除毒死蜱外，残留量均超过国家标准。水稻抽穗后用药，农药残留量明显提高，甲胺磷、乙酰甲胺磷、三唑磷、毒死蜱常规剂量用药2次，除乙酰甲胺磷未超标外，其余残留量都高于国家标准。吡虫啉抽穗前后使用，其残留量均低于食品中最高允许标准。农药残留量与糙米贮存期有关，一般贮存90d后，农药残量即低于允许残留标准。降低农药施用次数，适当降低用药量，尽量选择抽穗前用药，选用高效、安全、低残留农药，是无公害水稻生产中的重要措施。

Effects of Different Pesticides,Application Rate and Dosage Used Before and After Rice Heading on Pesticide's Residue in Rice

The variety of pesticide,the date and dosage and frequency of employing pesticides were connected with the security of rice grain.Among the pesticides for experiments,besides dichlorovos,others were all detected in the rice grain and the pesticicde residues of triazophos were the most,that of acephate and methamidophos were next and that of chlorpyrifos was the least.When pesticides were employed two times in the period before heading,residues of methamidophos and triazophos were beyond the national standar...