水稻植株不同部位中三唑磷含量动态分布趋势的研究

Dynamic Variation of Triazophos in Different Parts in Rice(Oryza Sativa L.)

为揭示三唑磷农药在水稻中的动态变化,研究了田间栽培条件下两个品种水稻(内2优6号和秀水09)不同组织部位中三唑磷分布和动态趋势。水稻抽穗前,经不同浓度三唑磷(2250、4500mL·hm-2)处理一次,分别于0、1、3、7、14、21、60d测定水稻叶片、叶鞘、茎秆和穗等部位中三唑磷含量。结果表明,水稻叶片、叶鞘中三唑磷含量动态分布趋势均为随时间延长而逐渐降低,施药后第21d,2种水稻品种叶片中三唑磷的降解率均大于95%;水稻茎秆、穗中三唑磷含量动态分布趋势均呈现单峰曲线变化,其含量随时间延长先增加后降低。水稻叶片、叶鞘、茎秆和穗中三唑磷出现最高浓度的时间存在显著性差异,分别为施药后第0、0、1～3和21d,进一步表明,水稻叶鞘中三唑磷含量动态分布与叶片中相应过程具有一致性,而茎秆和穗中三唑磷含量动态分布与其在叶片和叶鞘中相应过程具有显著的滞后性。结合实际生产,水稻抽穗前应严格控制三唑磷的施用量和施用次数。

In order to determine the dynamic variation of triazophos in different parts in rice,the pesticide residue in different plant tissues were examined in two varieties rice（Nei 2 you 6,Xiushui09）grew under field conditions.The triazophos（2 250 and 4 500 mL·hm-2）was sprayed before rice tasselled with one time.Triazophos content in rice leaf,leaf sheath,stem and ear were tested in 0,1,3,7,14,21 and 60 d after spraying,respectively.The results showed that the variation trend of triazophos content in rice leaf and leaf sheath decreased with time,and the triazophos degradation ratios in leaf were higher than 95% in two rice varieties at the 21st day in all treatments with different triazophos concentrations.The variation trend of triazophos concentration in rice stem and ear were all shown as a curve with single peak,and the concentration increased at early stage after spraying then reduced with culturing time.The highest triazophos concentration in rice leaf,leaf sheath,stem and ear appeared at different time,i.e,0 d,0 d,1～3 d and 21 d,respectively.Furthermore,the variation trend of triazophos concentration in leaf sheath was identical with that in leaf,but the trend in stem and ear significantly lagged behind that in leaf and leaf sheath.Conclusively,the application amount and frequency of triazophos must be strictly controlled before the rice heading.