功夫在大豆及土壤中的残留动态研究

为了制订功夫在大豆上安全使用标准，采用田间试验了研究了功夫在大豆茎叶和土壤中的残留动态，应用ＧＬＣ法测定了功夫在青事，成熟大豆和土壤中的残留量。２年的试验结果表明，功夫在大豆茎叶和土壤中消失较快，其半衰期分别为６．６－７．１ｄ和６．７－１１．６ｄ。施药量为１５ｇ／ｈｍ＾２，施药２次，收获时土壤中的残留量为０．００８ｍｇ／ｋｇ；在青豆和成熟大豆中残留量均低于最低检测浓度。

Study on the Residual Dynamics of Cyhalothrin in Soybeen and Soil

In order to make up the standards for safe use of cyhalothrin on soybeen, a field experiment was conducted to study the residual dynamics of cyhalothrin in soil and leaves of soybeen. The residues of cyhalothrin in green soybeen, mature soybeen and soil were determined by GLC. Results of two years'study showed that cyhalothrin dissipated rapidly from leaves and soil. Its half lives in leaves and soil were 6.6-7.1 and 6.7-11.6 days, respectively. The soybeen field was sprayed twice with cyhalothrin at a rate of 15 g a.i./hm². At harvest, the final residues of cyhalothrin in soil was 0.008 mg/kg, the residues of cyhalothrin in green and mature soybeen were all below their detectable limits(0.004 mg/kg). Cyhalothrin is a pesticide of easy dissipation (T_1/2<30 d). It is safe if applied twice at a recommended rate (7.5 g a.i./hm²).